/**

* 小结：

* 1.IP和端口

* 1）IP定位主机

* 2）端口定位程序

*

* 2.InetAddress：表示网络中一个地址

* InetAddress.getByName("www.baidu.com");

*

* 3.TCP/IP编程：

* 1）客户端/服务器：客户端发送请求，服务器接收请求并响应。

* 2）ServerSocket Socket

*

*

*/

import java.util.*;

import java.io.*;

import java.net.*;

public class SocketTest {

/**

* 表示一台主机地址

*

* @throws UnknownHostException

*/

static void testInetAddress() throws UnknownHostException {

InetAddress address = InetAddress.getByName("www.baidu.com");

System.out.println(address);// www.baidu.com/119.75.217.56

InetAddress address2 = InetAddress.getByName("localhost");

System.out.println(address2);// localhost/127.0.0.1

}

static void testServerSocket() throws IOException {

// 创建ServerSocket的对象

ServerSocket serverSocket = new ServerSocket(8989);

// 接受客户端的请求，返回socket

Socket socket = serverSocket.accept();

// 通过输入输出流和客户端交互

OutputStream out = socket.getOutputStream();

PrintWriter writer = new PrintWriter(out);

writer.write("来自服务器的问候");

writer.close();

// 关闭socket

socket.close();

serverSocket.close();

}

void testServerSocket2() throws Exception {

// 创建ServerSocket的对象

ServerSocket serverSocket = new ServerSocket(8686);

// 接受客户端的请求，返回socket

Socket socket = serverSocket.accept();

InputStream in = new FileInputStream("abc.png");

byte[] buffer = new byte[1024];

int len = 0;

// 通过输入输出流和客户端交互

OutputStream out = socket.getOutputStream();

while ((len = in.read(buffer)) != -1) {

out.write(buffer, 0, len);

}

out.close();

in.close();

// 关闭socket

socket.close();

serverSocket.close();

}

static void testUrl() throws Exception{

URL url=new URL("http://localhost:8080/helloworld/abcd.txt");

System.out.println(url.getPath());

System.out.println(url.getFile());

URLConnection urlConnection=url.openConnection();

System.out.println(urlConnection);

InputStream in = urlConnection.getInputStream();

OutputStream out = new FileOutputStream("test.txt");

byte[] buffer = new byte[1024];

int len = 0;

// 通过输入输出流和客户端交互

while ((len = in.read(buffer)) != -1) {

out.write(buffer, 0, len);

}

out.close();

in.close();

}

public static void main(String[] args) throws Exception {

// // testInetAddress();

// SocketTest server=new SocketTest();

// server.testServerSocket2();

testUrl();

}

}