In this web service tutorial, we will see the introduction of webservices in java and some jargons of web services.

Webservices in java are used everywhere nowadays. When human interacts with any web page, it involves request and response via HTML. When you interact with the webpage, browser sends a request and then renders response and shows in form of HTML. Similarly, web services also involve request and response but in the form of XML or JSON or plain text. It generally used for other applications or programs to consume and make use of information.

For example:
You are creating a website which shows weather information of important cities in the world. You can actually consume already exposed web services and get the data for the cities. You will get the response in form of XML or JSON, you can parse it and show it on your website.

Let’s go to more formal definition now:

   
<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions targetNamespace="http://webservices.javapostsforlearning.arpit.org" xmlns:apachesoap="http://xml.apache.org/xml-soap" xmlns:impl="http://webservices.javapostsforlearning.arpit.org" xmlns:intf="http://webservices.javapostsforlearning.arpit.org" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdlsoap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<!--WSDL created by Apache Axis version: 1.4
Built on Apr 22, 2006 (06:55:48 PDT)-->
 <wsdl:types>
  <schema elementFormDefault="qualified" targetNamespace="http://webservices.javapostsforlearning.arpit.org" xmlns="http://www.w3.org/2001/XMLSchema">
   <element name="sayHelloWorld">
    <complexType>
     <sequence>
      <element name="name" type="xsd:string"/>
     </sequence>
    </complexType>
   </element>
   <element name="sayHelloWorldResponse">
    <complexType>
     <sequence>
      <element name="sayHelloWorldReturn" type="xsd:string"/>
     </sequence>
    </complexType>
   </element>
  </schema>
 </wsdl:types>
   <wsdl:message name="sayHelloWorldRequest">
      <wsdl:part element="impl:sayHelloWorld" name="parameters"/>
   </wsdl:message>
   <wsdl:message name="sayHelloWorldResponse">
      <wsdl:part element="impl:sayHelloWorldResponse" name="parameters"/>
   </wsdl:message>
   <wsdl:portType name="HelloWorld">
      <wsdl:operation name="sayHelloWorld">
         <wsdl:input message="impl:sayHelloWorldRequest" name="sayHelloWorldRequest"/>
         <wsdl:output message="impl:sayHelloWorldResponse" name="sayHelloWorldResponse"/>
      </wsdl:operation>
   </wsdl:portType>
   <wsdl:binding name="HelloWorldSoapBinding" type="impl:HelloWorld">
      <wsdlsoap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
      <wsdl:operation name="sayHelloWorld">
         <wsdlsoap:operation soapaction="proxy.php?url="/>
         <wsdl:input name="sayHelloWorldRequest">
            <wsdlsoap:body use="literal"/>
         </wsdl:input>
         <wsdl:output name="sayHelloWorldResponse">
            <wsdlsoap:body use="literal"/>
         </wsdl:output>
      </wsdl:operation>
   </wsdl:binding>
   <wsdl:service name="HelloWorldService">
      <wsdl:port binding="impl:HelloWorldSoapBinding" name="HelloWorld">
         <wsdlsoap:address location="http://localhost:8080/SimpleSOAPExample/services/HelloWorld"/>
      </wsdl:port>
   </wsdl:service>
</wsdl:definitions>

Types of webservices in java:

• REST
• SOAP

You can read about differences and usage of REST and SOAP web services.

That’s all about the webservices in java.

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• Difference between SOAP and REST web services
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcat
• Create RESTful web service in java(JAX-RS) using jersey
• RESTful web service JAXRS json example using jersey
• RESTful web service JAXRS CRUD example using jersey
• AngularJS RESTful web service JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Rest simple example
• Spring Rest json example
• Spring Rest xml example
• Spring Rest CRUD example

In previous post, we have created a very simple Spring Restful web services  which returns json. In this post, we will see Spring Restful web services which will return xml as example.

Here are steps to create a simple Spring Restful web services which will return xml.

1) Create a dynamic web project using maven in eclipse.

pom.xml will be as follows:
pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.arpit.java2blog</groupId>
  <artifactId>SpringRestfulWebServicesWithJSONExample</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringRestfulWebServicesWithJSONExample Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
   <groupId>javax.servlet</groupId>
   <artifactId>javax.servlet-api</artifactId>
   <version>3.1.0</version>
  </dependency>

  <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-core</artifactId>
   <version>${spring.version}</version>
  </dependency>
  <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-webmvc</artifactId>
   <version>${spring.version}</version>
  </dependency>

 </dependencies>
 <build>
  <finalName>SpringRestfulWebServicesWithJSONExample</finalName>

  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.1</version>
    <configuration>
     <source>${jdk.version}</source>
     <target>${jdk.version}</target>
    </configuration>
   </plugin>
  </plugins>

 </build>
 <properties>
  <spring.version>4.2.1.RELEASE</spring.version>
  <jdk.version>1.7</jdk.version>
 </properties>
</project>

Spring application configuration:

3) Change web.xml as below:

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
  <servlet>
 <servlet-name>springrest</servlet-name>
 <servlet-class>
  org.springframework.web.servlet.DispatcherServlet
 </servlet-class>
 <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
 <servlet-name>springrest</servlet-name>
 <url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>

4) create a xml file named springrest-servlet.xml in /WEB-INF/ folder.
Please change context:component-scan if you want to use different package for spring to search for controller.Please refer to spring mvc hello world example for more understanding.

<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

 <mvc:annotation-driven/>
<context:component-scan base-package="org.arpit.java2blog.controller" />

</beans>

Create bean class

5) Create a bean name “Country.java” in org.arpit.java2blog.bean.

package org.arpit.java2blog.bean;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="country")
public class Country{

    private int id;
    private String countryName;

    public Country() {

    }
    public Country(int i, String countryName) {
        super();
        this.id = i;
        this.countryName = countryName;
    }

    @XmlElement
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }

    @XmlElement
    public String getCountryName() {
        return countryName;
    }
    public void setCountryName(String countryName) {
        this.countryName = countryName;
    }
}

We need to annotate bean class with @XmlRootElement and @XmlElement to support for xml. As you can see we have annotated Country class with
JAXB annotation but if you want to have support for list, we can not edit ArrayList class, so we can create another class called CountryList  and we can annotate with JAXB annotation in that class to support xml output.
CountryList.java

package org.arpit.java2blog.bean;

import java.util.List;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "country-list")
public class CountryList {

    ListlistOfCountries;

    public CountryList() {
        super();
    }
    public CountryList(ListlistOfCountries) {
        this.listOfCountries=listOfCountries;
    }
    public ListgetListOfCountries() {
        return listOfCountries;
    }

    @XmlElement(name = "country")
    public void setListOfCountries(ListlistOfCountries) {
        this.listOfCountries = listOfCountries;
    }

}

Create controller

6) Create a controller named “CountryController.java”

package org.arpit.java2blog.controller;

import java.util.ArrayList;
import java.util.List;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.bean.CountryList;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CountryController {

    @RequestMapping(value = "/countries", method = RequestMethod.GET,headers="Accept=application/xml")
    public CountryList getCountries()
    {
        CountryList countryList=createCountryList();
        return countryList;
    }

    @RequestMapping(value = "/country/{id}", method = RequestMethod.GET)
    public Country getCountryById(@PathVariable int id)
    {
        ListlistOfCountries = new ArrayList();
        CountryList countryList=createCountryList();
        listOfCountries=countryList.getListOfCountries();
        for (Country country: listOfCountries) {
            if(country.getId()==id)
                return country;
        }

        return null;
    }

    /// Utiliy method to create country list.
    public CountryList createCountryList()
    {
        Country indiaCountry=new Country(1, "India");
        Country chinaCountry=new Country(4, "China");
        Country nepalCountry=new Country(3, "Nepal");
        Country bhutanCountry=new Country(2, "Bhutan");

        ListlistOfCountries = new ArrayList();
        listOfCountries.add(indiaCountry);
        listOfCountries.add(chinaCountry);
        listOfCountries.add(nepalCountry);
        listOfCountries.add(bhutanCountry);
        return new CountryList(listOfCountries);
    }
}

@PathVariable: Used to inject values from the URL into a method parameter.This way you inject id in getCountryById method .

We are not providing any view information in springrest-servlet.xml as we do in Spring MVC. If we need to directly get resource from controller, we need to return @ResponseBody as per Spring 3 but with Spring 4, we can use @RestController for that.
In spring 4.0, we can use @RestController which is combination of @Controller + @ResponseBody.

@RestController = @Controller + @ResponseBody

6) It ‘s time to do maven build.

 

Mar 26, 2016 1:45:51 AM org.springframework.web.servlet.PageNotFound noHandlerFound
WARNING: No mapping found for HTTP request with URI [/SpringRestfulWebServicesWithXMLExample/] in DispatcherServlet with name 'SpringRestfulWebServicesWithJSONExample'

You will get following output:

 

10) Now pass country id as a parameter to url.
“http://localhost:8080/SpringRestfulWebServicesWithXMLExample/country/2”.

 

That’s all about Spring Restful web services xml example.

We have already seen SOAP web services and RESTful web services in detail before. In this post, we are going to see differences between SOAP and REST web services.

This is all about Difference between SOAP and REST web services in java. If you find more differences, please comment, so that I can include them in post.

1. What are web services?

2. What are features of web services?

• Interoperability
• Reuse already developed(old) functionality into new software:
• Loosely Coupled
• Extensibility

3. What are different types of web services?

<?xml version="1.0" encoding="UTF-8"?>
<endpoints xmlns="http://java.sun.com/xml/ns/jax-ws/ri/runtime" version="2.0">
  <endpoint
     name="HelloWorldWS"
     implementation="org.arpit.javapostsforlearning.webservice.HelloWorldImpl"
     url-pattern="/HelloWorldWS"/>
</endpoints> 

You may also like:

• restful web services interview questions
• Data structure and algorithm Interview Questions
• Spring interview questions
• Hibernate interview questions
• Core java interview questions
• Java Collections interview questions
• Java String interview questions
• OOPs interview questions in java
• Java Multithreading interview questions
• Exceptional handling interview questions in java
• Java Serialization interview questions in java

1. What is REST?

REST is an architectural style which was brought in by Roy Fielding in 2000 in his doctoral thesis.

In the REST architecture style, clients and servers exchange representations of resources by using a standardized interface and protocol.REST isn’t protocol specific, but when people talk about REST they usually mean REST over HTTP.

2. What are Restful web services?

In the web services terms, REpresentational State Transfer (REST) is a stateless client-server architecture in which the web services are viewed as resources and can be identified by their URIs. Web services client uses that URI to access the resource.
It consists of two components REST server which provides access to the resources and a REST client which accesses and modify the REST resources.

3. What are important features of Restful web services?

Some important features of Restful web services are:
Resource identification through URI:Resources are identified by their URIs (typically links on internet). So, a client can directly access a RESTful Web Services using the URIs of the resources (same as you put a website address in the browser’s address bar and get some representation as response).
Uniform interface: Resources are manipulated using a fixed set of four create, read, update, delete operations: PUT, GET, POST, and DELETE.
Client-Server: A clear separation concerns is the reason behind this constraint. Separating concerns between the Client and Server helps improve portability in the Client and Scalability of the server components.
Stateless: each request from client to server must contain all the information necessary to understand the request, and cannot take advantage of any stored context on the server.
Cache: to improve network efficiency responses must be capable of being labeled as cacheable or non-cacheable.
Named resources – the system is comprised of resources which are named using a URL.
Interconnected resource representations – the representations of the resources are interconnected using URLs, thereby enabling a client to progress from one state to another.
Layered components – intermediaries, such as proxy servers, cache servers, gateways, etc, can be inserted between clients and resources to support performance, security, etc.
Self-descriptive messages: Resources are decoupled from their representation so that their content can be accessed in a variety of formats, such as HTML, XML, plain text, PDF, JPEG, JSON, and others.

4. What are HTTP methods that can be used in Restful web services?

RESTful web services use HTTP protocol methods for the operations they perform.
Some important Methods are:
GET : It defines a reading access of the resource without side-effects.This operation is idempotent i.e.they can be applied multiple times without changing the result
PUT : It is generally used for updating resource. It must also be idempotent.
DELETE : It removes the resources. The operations are idempotent i.e. they can get repeated without leading to different results.
POST : It is used for creating a new resource. It is not idempotent.

5. What do you mean by Idempotent and which HTTP methods are idempotent?

Idempotent means result of multiple successful request will not change state of resource after initial application
For example : Delete is idempotent method because when you first time use delete, it will delete the resource (initial application) but after that, all other request will have no result because resource is already deleted. Get, put and delete are HTTP Idempotent methods.

6. What are differences between Post and Put Http methods?

POST :It is used for creating a new resource. It is not idempotent.
PUT : It is generally used for updating resource. It is idempotent.
Idempotent means result of multiple successful request will not change state of resource after initial application

7. What happens if resources are shared by multiple clients? Do you need to make it thread safe explicitly?

New resource instance is created for each request, so you don’t need to implement thread safety or synchronization aid. It is by default thread safe.

8. What is JAX-RS?

Java API for RESTful Web Services (JAX-RS), is a set if APIs to developer REST service. JAX-RS is part of the Java EE6, and make developers to develop REST web application easily.

9. What are REST frameworks that you are aware of and which can be used to create Restful webservices?

There are multiple Rest framework that can be used to create Restful web services such as

• Jersey
• RestEasy
• Restlet
• CFX
• Spring Rest webservices

@Path : This is used to set path for URI at class level or method level
@GET,@POST,@PUT,@DELETE  : There are annotations corresponds to HTTP methods
@Produces(MediaType.TEXT_XML [, more-types ]): @Produces defines which MIME type is delivered by a method
@PathParam: Used to inject values from the URL into a method parameter.
@Consumes(MediaType.TEXT_XML) : @Cosumes defines which MIME type will be consumed by the method .

11. Can you use get method to create Resources rather than post?

No, Get should be used only for resource retrieval and not for resource creation.

12.  What are ways to test Restful web services?

You require a restful client to test restful web services. You can use:

• Postman for chrome browser
• poster for firefox

You may also like:

• Web services interview questions
• Data structure and algorithm Interview Questions
• Spring interview questions
• Hibernate interview questions
• Core java interview questions
• Java Collections interview questions
• Java String interview questions
• OOPs interview questions in java
• Java Multithreading interview questions
• Exceptional handling interview questions in java
• Java Serialization interview questions in java

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• Difference between SOAP and REST web services
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcat
• Create RESTful web service in java(JAX-RS) using jersey
• RESTful web service JAXRS json example using jersey
• RESTful web service JAXRS CRUD example using jersey
• AngularJS RESTful web service
• JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Rest simple example
• Spring Rest json example
• Spring Rest xml example
• Spring Rest CRUD example

In previous post, we have already seen Spring Restful web services which returns json as response.In this post, we will extend same example and create Restful web services which will provide CRUD(Create, read, update and delete) operation example.If you want complete integration with hibernate and mysql, you can go through Spring Restful hibernate mysql example.

We will use following annotations for CRUD operation.

Idempotent means result of multiple successful request will not change state of resource after initial application
For example :
Delete is idempotent method because when you first time use delete, it will delete the resource (initial application) but after that, all other request will have no result because resource is already deleted.

Post is not idempotent method because when you use post to create resource , it will keep creating resource for each new request, so result of multiple successful request will not be same.

Source code:

Here are steps to create a Spring Restful web services  which will provide CRUD opertion.

1) Create a dynamic web project using maven in eclipse named “SpringRestfulWebServicesCRUDExample”

Maven dependencies

2) We need to add Jackson json utility in the classpath.

<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
             <version>2.4.1</version>
 </dependency>

Spring will load Jackson2JsonMessageConverter into its application context automatically. Whenever you request resource as json with accept headers=”Accept=application/json”, then Jackson2JsonMessageConverter comes into picture and convert resource to json format.

Now change pom.xml as follows:
pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.arpit.java2blog</groupId>
  <artifactId>SpringRestfulWebServicesWithJSONExample</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringRestfulWebServicesWithJSONExample Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
   <groupId>javax.servlet</groupId>
   <artifactId>javax.servlet-api</artifactId>
   <version>3.1.0</version>
  </dependency>

  <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-core</artifactId>
   <version>${spring.version}</version>
  </dependency>
  <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-webmvc</artifactId>
   <version>${spring.version}</version>
  </dependency>
   <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
             <version>2.4.1</version>
        </dependency>
 </dependencies>
 <build>
  <finalName>SpringRestfulWebServicesWithJSONExample</finalName>

  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.1</version>
    <configuration>
     <source>${jdk.version}</source>
     <target>${jdk.version}</target>
    </configuration>
   </plugin>
  </plugins>

 </build>
 <properties>
  <spring.version>4.2.1.RELEASE</spring.version>
  <jdk.version>1.7</jdk.version>
 </properties>
</project>

Spring application configuration:

3) Change web.xml as below:

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
  <servlet>
 <servlet-name>springrest</servlet-name>
 <servlet-class>
  org.springframework.web.servlet.DispatcherServlet
 </servlet-class>
 <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
 <servlet-name>springrest</servlet-name>
 <url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>

4) create a xml file named springrest-servlet.xml in /WEB-INF/ folder.
Please change context:component-scan if you want to use different package for spring to search for controller.Please refer to spring mvc hello world example for more understanding.

<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

 <mvc:annotation-driven/>
<context:component-scan base-package="org.arpit.java2blog.controller" />

</beans>

Create bean class

4) Create a bean name “Country.java” in org.arpit.java2blog.bean.

package org.arpit.java2blog.bean;

public class Country{

    int id;
    String countryName;
    long population;

    public Country() {
        super();
    }
    public Country(int i, String countryName,long population) {
        super();
        this.id = i;
        this.countryName = countryName;
        this.population=population;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getCountryName() {
        return countryName;
    }
    public void setCountryName(String countryName) {
        this.countryName = countryName;
    }
    public long getPopulation() {
        return population;
    }
    public void setPopulation(long population) {
        this.population = population;
    }

}

Create Controller

5) Create a controller named “CountryController.java” in package org.arpit.java2blog.controller

package org.arpit.java2blog.controller;

import java.util.List;
import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.service.CountryService;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CountryController {

    CountryService countryService = new CountryService();

    @RequestMapping(value = "/countries", method = RequestMethod.GET, headers = "Accept=application/json")
    public List getCountries() {
        List listOfCountries = countryService.getAllCountries();
        return listOfCountries;
    }

    @RequestMapping(value = "/country/{id}", method = RequestMethod.GET, headers = "Accept=application/json")
    public Country getCountryById(@PathVariable int id) {
        return countryService.getCountry(id);
    }

    @RequestMapping(value = "/countries", method = RequestMethod.POST, headers = "Accept=application/json")
    public Country addCountry(@RequestBody Country country) {
        return countryService.addCountry(country);
    }

    @RequestMapping(value = "/countries", method = RequestMethod.PUT, headers = "Accept=application/json")
    public Country updateCountry(@RequestBody Country country) {
        return countryService.updateCountry(country);

    }

    @RequestMapping(value = "/country/{id}", method = RequestMethod.DELETE, headers = "Accept=application/json")
    public void deleteCountry(@PathVariable("id") int id) {
        countryService.deleteCountry(id);

    }
}

Create Service class

6) Create a class CountryService.java in package org.arpit.java2blog.service
It is just a helper class which should be replaced by database implementation. It is not very well written class, it is just used for demonstration.

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.arpit.java2blog.bean.Country;

/*
 * It is just a helper class which should be replaced by database implementation.
 * It is not very well written class, it is just used for demonstration.
 */
public class CountryService {

    static HashMap<Integer,Country> countryIdMap=getCountryIdMap();

    public CountryService() {
        super();

        if(countryIdMap==null)
        {
            countryIdMap=new HashMap<Integer,Country>();
            // Creating some objects of Country while initializing
            Country indiaCountry=new Country(1, "India",10000);
            Country chinaCountry=new Country(4, "China",20000);
            Country nepalCountry=new Country(3, "Nepal",8000);
            Country bhutanCountry=new Country(2, "Bhutan",7000);

            countryIdMap.put(1,indiaCountry);
            countryIdMap.put(4,chinaCountry);
            countryIdMap.put(3,nepalCountry);
            countryIdMap.put(2,bhutanCountry);
        }
    }

    public List getAllCountries()
    {
        List countries = new ArrayList(countryIdMap.values());
        return countries;
    }

    public Country getCountry(int id)
    {
        Country country= countryIdMap.get(id);
        return country;
    }
    public Country addCountry(Country country)
    {
        country.setId(getMaxId()+1);
        countryIdMap.put(country.getId(), country);
        return country;
    }

    public Country updateCountry(Country country)
    {
        if(country.getId()<=0)
            return null;
        countryIdMap.put(country.getId(), country);
        return country;

    }
    public void deleteCountry(int id)
    {
        countryIdMap.remove(id);
    }

    public static HashMap<Integer, Country> getCountryIdMap() {
        return countryIdMap;
    }

    // Utility method to get max id
    public static int getMaxId()
    { int max=0;
    for (int id:countryIdMap.keySet()) {
        if(max<=id)
            max=id;

    }
    return max;
    }
}

7) It ‘s time to do maven build.

Right click on project -> Run as -> Maven build

8) Provide goals as clean install (given below) and click on run

Run the application

9) Right click on project -> run as -> run on server

Select apache tomcat and click on finish

10) We will test this application in  postman , UI based client for testing restful web applications. It is chrome plugin. Launch postman.If you want java based client, then you can also use how to send get or post request in java.

Get method

11) Test your get method Spring REST service
URL :“http://localhost:8080/SpringRestfulWebServicesCRUDExample/countries”.

You will get following output:

Post method

12) Post method is used to create new resource. Here we are adding new Country England to country list, so you can see we have used new country json in post body.
URL: “http://localhost:8080/SpringRestfulWebServicesCRUDExample/countries”.

Use get method to check if above country have been added to country list.

Put Method

13) Put method is used to update resource. Here will update population of nepal using put method.
We will update country json in body of request.
URL : “http://localhost:8080/SpringRestfulWebServicesCRUDExample/countries”

Use get method to check population of nepal.

Delete method

14) Delete method is used to delete resource.We will pass id of country which needs to be deleted as PathParam. We are going delete id:4 i.e. china to demonstrate delete method.

URL : “http://localhost:8080/SpringRestfulWebServicesCRUDExample/country/4”

Use get method to check country list.

As you can see, we have deleted country with id 4 i.e. china

Project structure:

We are done with Spring Restful web services json CRUD example. If you are still facing any issue, please comment.

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• Difference between SOAP and REST web services
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcatCreate
• RESTful web service in java(JAX-RS) using jersey
• RESTful web service JAXRS json example using jersey
• RESTful web service JAXRS CRUD example using jersey
• AngularJS RESTful web service JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Rest simple example
• Spring Rest json example
• Spring Rest xml example
• Spring Rest CRUD example

In previous post, we have already seen simple Restful web services(JAXWS)  which returns json as response.In this post, we will extend same example and create Restful web services(JAXWS) using jersey which will provide CRUD(Create, read, update and delete) operation example.

We will use following annotations for CRUD operation.

Idempotent means result of multiple successful request will not change state of resource after initial application
For example :
Delete is idempotent method because when you first time use delete, it will delete the resource (initial application) but after that, all other request will have no result because resource is already deleted.

Post is not idempotent method because when you use post to create resource , it will keep creating resource for each new request, so result of multiple successful request will not be same.

Source code:

Here are steps to create a simple Restful web services(JAXWS)  using jersey which will provide CRUD opertion.
1) Create a dynamic web project using maven in eclipse named “JAXRSJsonCRUDExample”

 
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
 </dependency>

Now create pom.xml as follows:
pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.arpit.java2blog</groupId>
 <artifactId>JAXRSJsonExample</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>JAXRSJsonExample Maven Webapp</name>
 <url>http://maven.apache.org</url>
   <properties>
        <jersey.version>1.18.3</jersey.version>
    </properties>
 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>3.8.1</version>
   <scope>test</scope>
  </dependency>

  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
  </dependency>
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
  </dependency>

  <dependency>
   <groupId>commons-logging</groupId>
   <artifactId>commons-logging</artifactId>
   <version>1.2</version>
  </dependency>
 </dependencies>
 <build>
  <finalName>JAXRSJsonExample</finalName>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
     <source>1.7</source>
     <target>1.7</target>
    </configuration>
   </plugin>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
     <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
   </plugin>
  </plugins>
 </build>

</project>

Application configuration:

3) create web.xml as below:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
 version="3.0">
 <display-name>Archetype Created Web Application</display-name>
 <servlet>
  <servlet-name>jersey-serlvet</servlet-name>
  <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
  <init-param>
   <param-name>com.sun.jersey.config.property.packages</param-name>
   <param-value>org.arpit.java2blog.controller</param-value>
  </init-param>
  <init-param>
   <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
   <param-value>true</param-value>
  </init-param>

  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>jersey-serlvet</servlet-name>
  <url-pattern>/rest/*</url-pattern>
 </servlet-mapping>
</web-app>

Create bean class

4) Create a bean name “Country.java” in org.arpit.java2blog.bean.

package org.arpit.java2blog.bean;

public class Country{

 int id;
 String countryName; 
 long population;

 public Country() {
 super();
 }
 public Country(int i, String countryName,long population) {
 super();
 this.id = i;
 this.countryName = countryName;
 this.population=population;
 }
 public int getId() {
 return id;
 }
 public void setId(int id) {
 this.id = id;
 }
 public String getCountryName() {
 return countryName;
 }
 public void setCountryName(String countryName) {
 this.countryName = countryName;
 }
 public long getPopulation() {
 return population;
 }
 public void setPopulation(long population) {
 this.population = population;
 } 

}

Create Controller

5) Create a controller named “CountryController.java” in package org.arpit.java2blog.controller

package org.arpit.java2blog.controller;

import java.util.List;

import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.service.CountryService;

@Path("/countries")
public class CountryController {

 CountryService countryService=new CountryService();

    @GET
    @Produces(MediaType.APPLICATION_JSON)
 public List getCountries()
 {

  List listOfCountries=countryService.getAllCountries();
  return listOfCountries;
 }

    @GET
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public Country getCountryById(@PathParam("id") int id)
 {
  return countryService.getCountry(id);
 }

    @POST
    @Produces(MediaType.APPLICATION_JSON)
 public Country addCountry(Country country)
 {
  return countryService.addCountry(country);
 }

    @PUT
    @Produces(MediaType.APPLICATION_JSON)
 public Country updateCountry(Country country)
 {
  return countryService.updateCountry(country);

 }

    @DELETE
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public void deleteCountry(@PathParam("id") int id)
 {
   countryService.deleteCountry(id);

 }

}

@Path(/your_path_at_class_level) : Sets the path to base URL + /your_path_at_class_level. The base URL is based on your application name, the servlet and the URL pattern from the web.xml” configuration file.

@Path(/your_path_at_method_level): Sets path to base URL + /your_path_at_class_level+ /your_path_at_method_level

@Produces(MediaType.APPLICATION_JSON[, more-types ]): @Produces defines which MIME type is delivered by a method annotated with @GET. In the example text (“text/json”) is produced.

Create Service class

package org.arpit.java2blog.service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.arpit.java2blog.bean.Country;

/*
 * It is just a helper class which should be replaced by database implementation.
 * It is not very well written class, it is just used for demonstration.
 */
public class CountryService {

 static HashMap<Integer,Country> countryIdMap=getCountryIdMap();

 public CountryService() {
  super();

  if(countryIdMap==null)
  {
   countryIdMap=new HashMap<Integer,Country>();
  // Creating some objects of Country while initializing
   Country indiaCountry=new Country(1, "India",10000);
   Country chinaCountry=new Country(4, "China",20000);
   Country nepalCountry=new Country(3, "Nepal",8000);
   Country bhutanCountry=new Country(2, "Bhutan",7000);

   countryIdMap.put(1,indiaCountry);
   countryIdMap.put(4,chinaCountry);
   countryIdMap.put(3,nepalCountry);
   countryIdMap.put(2,bhutanCountry);
  }
 }

 public List getAllCountries()
 {
  List countries = new ArrayList(countryIdMap.values());
  return countries;
 }

 public Country getCountry(int id)
 {
  Country country= countryIdMap.get(id);
  return country;
 }
 public Country addCountry(Country country)
 {
  country.setId(countryIdMap.size()+1);
  countryIdMap.put(country.getId(), country);
  return country;
 }

 public Country updateCountry(Country country)
 {
  if(country.getId()<=0)
   return null;
  countryIdMap.put(country.getId(), country);
  return country;

 }
 public void deleteCountry(int id)
 {
  countryIdMap.remove(id);
 }

 public static HashMap<Integer, Country> getCountryIdMap() {
  return countryIdMap;
 }
}

7) It ‘s time to do maven build.

Run the application

9) Right click on project -> run as -> run on server

Select apache tomcat and click on finish

10) We will test this application in  postman , UI based client for testing restful web applications. It is chrome plugin. Launch postman. If you want java based client, then you can also use how to send get or post request in java.

Get method

11) Test your get method REST service
URL :“http://localhost:8080/JAXRSJsonCRUDExample/rest/countries”.

You will get following output:

Post method

12) Post method is used to create new resource. Here we are adding new Country England to country list, so you can see we have used new country json in post body.
URL: “http://localhost:8080/JAXRSJsonCRUDExample/rest/countries”.

Use get method to check if above country have been added to country list.

Put Method

13) Put method is used to update resource. Here will update population of nepal using put method.
We will update country json in body of request.
URL : “http://localhost:8080/JAXRSJsonCRUDExample/rest/countries”

Use get method to check population of nepal.

Delete method

14) Delete method is used to delete resource.We will pass id of country which needs to be deleted as PathParam. We are going delete id:4 i.e. china to demonstrate delete method.

URL : “http://localhost:8080/JAXRSJsonCRUDExample/rest/countries/4”

Use get method to check country list.

As you can see, we have deleted country with id 4 i.e. china

Project structure:

We are done with Restful web services json CRUD example using jersey. If you are still facing any issue, please comment.

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcat
• Create RESTful web service in java(JAX-RS) using jersey
• RESTful web service
• JAXRS json example using jersey
• RESTful web service JAXRS CRUD example using jersey
• AngularJS RESTful web service JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Restful web services simple example
• Spring Restful web services json example
• Spring Restful web services CRUD example

1) Create a dynamic web project using maven in eclipse named “JAXRSJsonCRUDExample”

<dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
 </dependency>

Now create pom.xml as follows:
pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.arpit.java2blog</groupId>
 <artifactId>JAXRSJsonExample</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>JAXRSJsonExample Maven Webapp</name>
 <url>http://maven.apache.org</url>
   <properties>
        <jersey.version>1.18.3</jersey.version>
    </properties>
 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>3.8.1</version>
   <scope>test</scope>
  </dependency>

  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
  </dependency>
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
  </dependency>

  <dependency>
   <groupId>commons-logging</groupId>
   <artifactId>commons-logging</artifactId>
   <version>1.2</version>
  </dependency>
 </dependencies>
 <build>
  <finalName>JAXRSJsonExample</finalName>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
     <source>1.7</source>
     <target>1.7</target>
    </configuration>
   </plugin>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
     <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
   </plugin>
  </plugins>
 </build>

</project>

Application configuration:

3) create web.xml as below:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
 version="3.0">
 <display-name>Archetype Created Web Application</display-name>
 <servlet>
  <servlet-name>jersey-serlvet</servlet-name>
  <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
  <init-param>
   <param-name>com.sun.jersey.config.property.packages</param-name>
   <param-value>org.arpit.java2blog.controller</param-value>
  </init-param>
  <init-param>
   <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
   <param-value>true</param-value>
  </init-param>

  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>jersey-serlvet</servlet-name>
  <url-pattern>/rest/*</url-pattern>
 </servlet-mapping>
</web-app>

Create bean class

4) Create a bean name “Country.java” in org.arpit.java2blog.bean.

package org.arpit.java2blog.bean;

public class Country{

    int id;
    String countryName;
    long population;

    public Country() {
        super();
    }
    public Country(int i, String countryName,long population) {
        super();
        this.id = i;
        this.countryName = countryName;
        this.population=population;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getCountryName() {
        return countryName;
    }
    public void setCountryName(String countryName) {
        this.countryName = countryName;
    }
    public long getPopulation() {
        return population;
    }
    public void setPopulation(long population) {
        this.population = population;
    }

}

Create Controller

5) Create a controller named “CountryController.java” in package org.arpit.java2blog.controller

package org.arpit.java2blog.controller;

import java.util.List;

import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.service.CountryService;

@Path("/countries")
public class CountryController {

    CountryService countryService=new CountryService();

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public List getCountries()
    {

        List listOfCountries=countryService.getAllCountries();
        return listOfCountries;
    }

    @GET
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
    public Country getCountryById(@PathParam("id") int id)
    {
        return countryService.getCountry(id);
    }

    @POST
    @Produces(MediaType.APPLICATION_JSON)
    public Country addCountry(Country country)
    {
        return countryService.addCountry(country);
    }

    @PUT
    @Produces(MediaType.APPLICATION_JSON)
    public Country updateCountry(Country country)
    {
        return countryService.updateCountry(country);

    }

    @DELETE
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
    public void deleteCountry(@PathParam("id") int id)
    {
        countryService.deleteCountry(id);

    }

}

@Path(/your_path_at_class_level) : Sets the path to base URL + /your_path_at_class_level. The base URL is based on your application name, the servlet and the URL pattern from the web.xml” configuration file.

@Path(/your_path_at_method_level): Sets path to base URL + /your_path_at_class_level+ /your_path_at_method_level

@Produces(MediaType.APPLICATION_JSON[, more-types ]): @Produces defines which MIME type is delivered by a method annotated with @GET. In the example text (“text/json”) is produced.

Create Service class

package org.arpit.java2blog.service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.exception.CountryNotFoundException;

/*
 * It is just a helper class which should be replaced by database implementation.
 * It is not very well written class, it is just used for demonstration.
 */
public class CountryService {

    static HashMap<Integer,Country> countryIdMap=getCountryIdMap();

    public CountryService() {
        super();

        if(countryIdMap==null)
        {
            countryIdMap=new HashMap<Integer,Country>();
            // Creating some object of countries while initializing
            Country indiaCountry=new Country(1, "India",10000);
            Country chinaCountry=new Country(4, "China",20000);
            Country nepalCountry=new Country(3, "Nepal",8000);
            Country bhutanCountry=new Country(2, "Bhutan",7000);

            countryIdMap.put(1,indiaCountry);
            countryIdMap.put(4,chinaCountry);
            countryIdMap.put(3,nepalCountry);
            countryIdMap.put(2,bhutanCountry);
        }
    }

    public List getAllCountries()
    {
        List countries = new ArrayList(countryIdMap.values());
        return countries;
    }

    public Country getCountry(int id)
    {
        Country country= countryIdMap.get(id);

        if(country == null)
        {
            throw new CountryNotFoundException("Country with id "+id+" not found");
        }
        return country;
    }
    public Country addCountry(Country country)
    {
        country.setId(getMaxId()+1);
        countryIdMap.put(country.getId(), country);
        return country;
    }

    public Country updateCountry(Country country)
    {
        if(country.getId()<=0)
            return null;
        countryIdMap.put(country.getId(), country);
        return country;

    }
    public void deleteCountry(int id)
    {
        countryIdMap.remove(id);
    }

    public static HashMap<Integer, Country> getCountryIdMap() {
        return countryIdMap;
    }

    // Utility method to get max id
    public static int getMaxId()
    {   int max=0;
    for (int id:countryIdMap.keySet()) {
        if(max<=id)
            max=id;

    }

    return max;
    }
}

<html>
  <head>

  <script src="proxy.php?url=https://ajax.googleapis.com/ajax/libs/angularjs/1.4.4/angular.js"></script>

    <title>AngularJS $http Rest example</title>
 <script type="text/javascript">
            var app = angular.module("CountryManagement", []);

            //Controller Part
            app.controller("CountryController", function($scope, $http) {

                $scope.countries = [];
                $scope.countryForm = {
                    id : -1,
                    countryName : "",
                    population : ""
                };

                //Now load the data from server
                _refreshCountryData();

                //HTTP POST/PUT methods for add/edit country
                // with the help of id, we are going to find out whether it is put or post operation

                $scope.submitCountry = function() {

                    var method = "";
                    var url = "";
                    if ($scope.countryForm.id == -1) {
                        //Id is absent in form data, it is create new country operation
                        method = "POST";
                        url = 'rest/countries';
                    } else {
                        //Id is present in form data, it is edit country operation
                        method = "PUT";
                        url = 'rest/countries';
                    }

                    $http({
                        method : method,
                        url : url,
                        data : angular.toJson($scope.countryForm),
                        headers : {
                            'Content-Type' : 'application/json'
                        }
                    }).then( _success, _error );
                };

                //HTTP DELETE- delete country by Id
                $scope.deleteCountry = function(country) {
                    $http({
                        method : 'DELETE',
                        url : 'rest/countries/' + country.id
                    }).then(_success, _error);
                };

             // In case of edit, populate form fields and assign form.id with country id
                $scope.editCountry = function(country) {

                    $scope.countryForm.countryName = country.countryName;
                    $scope.countryForm.population = country.population;
                    $scope.countryForm.id = country.id;
                };

                /* Private Methods */
                //HTTP GET- get all countries collection
                function _refreshCountryData() {
                    $http({
                        method : 'GET',
                        url : 'http://localhost:8080/AngularjsJAXRSCRUDExample/rest/countries'
                    }).then(function successCallback(response) {
                        $scope.countries = response.data;
                    }, function errorCallback(response) {
                        console.log(response.statusText);
                    });
                }

                function _success(response) {
                    _refreshCountryData();
                    _clearFormData()
                }

                function _error(response) {
                    console.log(response.statusText);
                }

                //Clear the form
                function _clearFormData() {
                    $scope.countryForm.id = -1;
                    $scope.countryForm.countryName = "";
                    $scope.countryForm.population = "";

                };
            });
        </script>
        <style>

       .blue-button{
     background: #25A6E1;
     filter: progid: DXImageTransform.Microsoft.gradient( startColorstr='#25A6E1',endColorstr='#188BC0',GradientType=0);
     padding:3px 5px;
     color:#fff;
     font-family:'Helvetica Neue',sans-serif;
     font-size:12px;
     border-radius:2px;
     -moz-border-radius:2px;
     -webkit-border-radius:4px;
     border:1px solid #1A87B9
           }

       .red-button{
    background: #CD5C5C;

    padding:3px 5px;
    color:#fff;
    font-family:'Helvetica Neue',sans-serif;
    font-size:12px;
    border-radius:2px;
    -moz-border-radius:2px;
    -webkit-border-radius:4px;
    border:1px solid #CD5C5C
           }

       table {
           font-family: "Helvetica Neue", Helvetica, sans-serif;
           width: 50%;
       }

       caption {
           text-align: left;
           color: silver;
           font-weight: bold;
           text-transform: uppercase;
           padding: 5px;
       }

       th {
           background: SteelBlue;
           color: white;
       }

       tbody tr:nth-child(even) {
           background: WhiteSmoke;
       }

       tbody tr td:nth-child(2) {
           text-align:center;
       }

       tbody tr td:nth-child(3),
       tbody tr td:nth-child(4) {
           text-align: center;
           font-family: monospace;
       }

       tfoot {
           background: SeaGreen;
           color: white;
           text-align: right;
       }

       tfoot tr th:last-child {
           font-family: monospace;
       }

       td,th{
            border: 1px solid gray;
            width: 25%;
            text-align: left;
            padding: 5px 10px;
        }

        </style>
    <head>
    <body ng-app="CountryManagement" ng-controller="CountryController">
         <h1>
           AngularJS Restful web services example using $http
        </h1>
        <form ng-submit="submitCountry()">
            <table>

                <tr>
                    <th colspan="2">Add/Edit country</th>
                 </tr>
                <tr>
                    <td>Country</td>
                    <td><input type="text" ng-model="countryForm.countryName" /></td>
                </tr>
                <tr>
                    <td>Population</td>
                    <td><input type="text" ng-model="countryForm.population"  /></td>
                </tr>
                <tr>
                    <td colspan="2"><input type="submit" value="Submit" class="blue-button" /></td>
                </tr>
            </table>
        </form>
        <table>
            <tr>

                <th>CountryName</th>
                <th>Population</th>
                <th>Operations</th>

            </tr>

            <tr ng-repeat="country in countries">

    <td> {{ country.countryName }}</td>
    <td >{{ country.population }}</td>

                <td><a ng-click="editCountry(country)" class="blue-button">Edit</a> | <a ng-click="deleteCountry(country)" class="red-button">Delete</a></td>
            </tr>

        </table>

  </body>
</html>

app.controller("CountryController", function($scope, $http) {

                $scope.countries = [];
...

//HTTP GET- get all countries collection
                function _refreshCountryData() {
                    $http({
                        method : 'GET',
                        url : 'http://localhost:8080/JAXRSJsonCRUDExample/rest/countries'
                    }).then(function successCallback(response) {
                        $scope.countries = response.data;
                    }, function errorCallback(response) {
                        console.log(response.statusText);
                    });
                }

8) It ‘s time to do maven build.

Right click on project -> Run as -> Maven build

Run the application

10) Right click on angularJSCrudExample.html -> run as -> run on server

Select apache tomcat and click on finish

10) You should be able to see below page
URL : “http://localhost:8080/AngularjsJAXRSCRUDExample/angularJSCrudExample.html”

Lets click on delete button corresponding to Nepal and you will see below screen:

Lets add new country France with population 15000

Click on submit and you will see below screen.

Now click on edit button corresponding to India and change population from 10000 to 100000.

Click on submit and you will see below screen:

Lets check Get method for Rest API

11) Test your get method REST service
URL :“http://localhost:8080/AngularjsJAXRSCRUDExample/rest/countries/”.

You will get following output:

As you can see , all changes have been reflected in above get call.

Project structure:

We are done with Restful web services json CRUD example using jersey. If you are still facing any issue, please comment.

AngularJS tutorial:

• AngularJs hello world example
• AngularJs controller examples
• AngularJs ng-repeat example
• AngularJs Built-in filter example
• AngularJs custom filter example
• AngularJs ajax example using $http
• AngularJS RESTful web service JAXRS CRUD example using $http

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• Difference between SOAP and REST web services
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcat
• Create RESTful web service in java(JAX-RS) using jersey
• RESTful web service
• JAXRS json example using jersey
• RESTful web service
• JAXRS CRUD example using jersey
• AngularJS RESTful web service
• JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Restful web services simple example
• Spring Restful web services json example
• Spring Restful web services CRUD example

In previous post, we have used @QueryParam for passing parameter to URL in JAX-RS @QueryParam example and  In case of @QueryParam, we pass parameters as well as its values separated by ? but in case of @MatrixParam, key value pairs are separared by semicolon(;).
For example:

http://localhost:8080/JAXRSJsonExample/rest/countries/country;id=1;countryName=India

Here Parameter names are id,countryName and its values are 3,Nepal respectively separated by ;.

Here are steps to create a JAXRS json example which will use @MatrixParam.

1) Follow steps on RESTful Web Services json example to create simple RESTful web services which uses @PathParam.
2) Change CountryRestService.java to use @MatrixParam as below.

package org.arpit.java2blog.jaxrs;

import java.util.ArrayList;
import java.util.List;

import javax.ws.rs.GET;
import javax.ws.rs.MatrixParam;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
/*
 * author: Arpit Mandliya
 * */
@Path("/countries")
public class CountryRestService {

 @GET
 @Produces(MediaType.APPLICATION_JSON)
 public List getCountries()
 {
 List listOfCountries = new ArrayList();
 listOfCountries=createCountryList();
 return listOfCountries;
 }

 @GET
 @Path("/country")
 @Produces(MediaType.APPLICATION_JSON)
 public Country getCountryById(@MatrixParam("id") int id,@MatrixParam("countryName") String countryName)
 {
 List listOfCountries = new ArrayList();
 listOfCountries=createCountryList();

 for (Country country: listOfCountries) {
 if(country.getId()==id && country.getCountryName().equalsIgnoreCase(countryName))
 return country;
 }

 return null;
 }

// Utiliy method to create country list.
 public List createCountryList()
 {
 Country indiaCountry=new Country(1, "India");
 Country chinaCountry=new Country(4, "China");
 Country nepalCountry=new Country(3, "Nepal");
 Country bhutanCountry=new Country(2, "Bhutan");

 List listOfCountries = new ArrayList();
 listOfCountries.add(indiaCountry);
 listOfCountries.add(chinaCountry);
 listOfCountries.add(nepalCountry);
 listOfCountries.add(bhutanCountry);
 return listOfCountries;
 }
}

That’s all. We need to run the application now.

Run the application

3) Right click on project -> run as -> run on server

Select apache tomcat and click on finish

4) Now pass country id and country name as parameters to url separated by ;.

“http://localhost:8080/JAXRSJsonExample/rest/countries/country;id=1;countryName=India”.

We are done with Restful web services json MatrixParam example. If you are still facing any issue, please comment.

• Introduction to web services
• Web services interview questions
• SOAP web service introduction
• RESTful web service introduction
• Difference between SOAP and REST web services
• SOAP web service example in java using eclipse
• JAX-WS web service eclipse tutorial
• JAX-WS web service deployment on tomcat
• Create RESTful web service in java(JAX-RS) using jersey
• RESTful web service
• JAXRS json example using jersey
• RESTful web service
• JAXRS CRUD example using jersey
• AngularJS RESTful web service
• JAXRS CRUD example using $http
• RESTful Web Services (JAX-RS) @QueryParam Example
• Spring Rest simple example
• Spring Rest json example
• Spring Rest xml example
• Spring Rest CRUD example

In previous post, we have used @PathParam for passing parameter to URL in RESTful Web Services json example and we have directly passed parameter values but JAXRS @QueryParam can be used to pass query parameters. In case of @QueryParam, we pass parameters as well as its values.
For example: http://localhost:8080/JAXRSJsonExample/rest/countries/country?id=3&countryName=Nepal
Here Parameter names are id,countryName and its values are 3,Nepal respectively.

http://localhost:8080/JAXRSJsonExample/rest/listOfCustomers?start=10&size=10

Here are steps to create a JAXRS json example which will use @QueryParam.

1) Follow steps on RESTful Web Services json example to create simple RESTful web services which uses @PathParam.
2) Change CountryRestService.java to use @QueryParam as below.

package org.arpit.java2blog.jaxrs;

import java.util.ArrayList;
import java.util.List;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
/*
 * author: Arpit Mandliya
 * */
@Path("/countries")
public class CountryRestService {

 @GET
 @Produces(MediaType.APPLICATION_JSON)
 public List getCountries()
 {
 List listOfCountries = new ArrayList();
 listOfCountries=createCountryList();
 return listOfCountries;
 }

 @GET
 @Path("/country")
 @Produces(MediaType.APPLICATION_JSON)
 public Country getCountryById(@QueryParam("id") int id,@QueryParam("countryName") String countryName)
 {
 List listOfCountries = new ArrayList();
 listOfCountries=createCountryList();

 for (Country country: listOfCountries) {
 if(country.getId()==id && country.getCountryName().equalsIgnoreCase(countryName))
 return country;
 }

 return null;
 }

// Utiliy method to create country list.
 public List createCountryList()
 {
 Country indiaCountry=new Country(1, "India");
 Country chinaCountry=new Country(4, "China");
 Country nepalCountry=new Country(3, "Nepal");
 Country bhutanCountry=new Country(2, "Bhutan");

 List listOfCountries = new ArrayList();
 listOfCountries.add(indiaCountry);
 listOfCountries.add(chinaCountry);
 listOfCountries.add(nepalCountry);
 listOfCountries.add(bhutanCountry);
 return listOfCountries;
 }
}

That’s all. We need to run the application now.

Run the application

3) Right click on project -> run as -> run on server

Select apache tomcat and click on finish

4) Now pass country id and country name as parameter to url.

“http://localhost:8080/JAXRSJsonExample/rest/countries/country?id=3&countryName=Nepal”.

We are done with Restful web services json QueryParam example. If you are still facing any issue, please comment.