Implementing Decorator design pattern

ShanukaPrabodha · ShanukaPrabodha · commit e87116c8eac1 · 2022-10-11T14:34:03.000+05:30
diff --git a/Basics/Design Pattern/decorator/Consultant.java b/Basics/Design Pattern/decorator/Consultant.java
@@ -0,0 +1,14 @@
+package design.pattern.decorator;
+
+public class Consultant extends Employee {
+	
+	public Consultant() {
+		description = "Consultant";
+	}
+
+	@Override
+	public double getSalary() {
+		return 70000;
+	}
+
+}
diff --git a/Basics/Design Pattern/decorator/Employee.java b/Basics/Design Pattern/decorator/Employee.java
@@ -0,0 +1,13 @@
+package design.pattern.decorator;
+
+public abstract class Employee {
+	
+	public String description;
+	
+	public Employee() {
+		description = "General employee details";
+	}
+	
+	abstract public double getSalary();
+
+}
diff --git a/Basics/Design Pattern/decorator/EmployeeCertification.java b/Basics/Design Pattern/decorator/EmployeeCertification.java
@@ -0,0 +1,21 @@
+package design.pattern.decorator;
+
+public class EmployeeCertification extends EmployeeQualification {
+
+	Employee employee;
+	
+	public EmployeeCertification(Employee employee) {
+		this.employee = employee;
+	}
+	
+	@Override
+	public String getDescription() {
+		return " Employee Certification ";
+	}
+
+	@Override
+	public double getSalary() {
+		return 30000 + employee.getSalary();
+	}
+
+}
diff --git a/Basics/Design Pattern/decorator/EmployeeQualification.java b/Basics/Design Pattern/decorator/EmployeeQualification.java
@@ -0,0 +1,7 @@
+package design.pattern.decorator;
+
+public abstract class EmployeeQualification extends Employee{
+	
+	public abstract String getDescription();
+
+}
diff --git a/Basics/Design Pattern/decorator/Engineer.java b/Basics/Design Pattern/decorator/Engineer.java
@@ -0,0 +1,13 @@
+package design.pattern.decorator;
+
+public class Engineer extends Employee {
+	
+	public Engineer() {
+		description = "Engineer";
+	}
+
+	@Override
+	public double getSalary() {
+		return 60000;
+	}
+}
diff --git a/Basics/Design Pattern/decorator/Manager.java b/Basics/Design Pattern/decorator/Manager.java
@@ -0,0 +1,14 @@
+package design.pattern.decorator;
+
+public class Manager extends Employee {
+	
+	public Manager() {
+		description = "Manager";
+	}
+
+	@Override
+	public double getSalary() {
+		return 80000;
+	}
+
+}
diff --git a/Basics/Design Pattern/decorator/TestPattern.java b/Basics/Design Pattern/decorator/TestPattern.java
@@ -0,0 +1,27 @@
+package design.pattern.decorator;
+
+public class TestPattern {
+
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+
+		Employee employee = new Engineer();
+		employee = new EmployeeCertification(employee);
+		employee = new WorkExperience(employee);
+
+		System.out.println(employee.description + " " + employee.getSalary());
+
+		Employee employee2 = new Consultant();
+		employee2 = new WorkExperience(new EmployeeCertification(employee2));
+
+		System.out.println(employee2.description + " " + employee2.getSalary());
+
+		System.out.println("PM salary = "
+				+ new WorkExperience(new EmployeeCertification(new Manager()))
+						.getSalary());
+
+	}
+
+}
diff --git a/Basics/Design Pattern/decorator/WorkExperience.java b/Basics/Design Pattern/decorator/WorkExperience.java
@@ -0,0 +1,20 @@
+package design.pattern.decorator;
+
+public class WorkExperience extends EmployeeQualification {
+	
+	Employee employee;
+	
+	public WorkExperience(Employee employee) {
+		this.employee = employee;
+	}
+
+	@Override
+	public String getDescription() {
+		return "Add Work experience.";
+	}
+
+	@Override
+	public double getSalary() {
+		return 20000 + employee.getSalary();
+	}
+}
