java网络编程

网络编程

通信双方地址

IP

端口号

要有一定的规则（网络通信协议，有两套参考模型）

OSI参考模型
TCP/IP协议，事实上的国际标准

域名也可以直接写，例如www.baidu.com

package wangluo;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class InetAddressTest {
	public static void main(String[] args) {
		InetAddress inet1;
		InetAddress inet2;
		try {
			inet1 = InetAddress.getByName("192.168.10.14");
			System.out.println(inet1);
			inet2 = InetAddress.getByName("www.baidu.com");
			System.out.println(inet2);
		} catch (UnknownHostException e) {

			e.printStackTrace();
		}
	
	}
}

本地回路地址：127.0.0.1，对应着Localhost

		InetAddress inet3 = InetAddress.getLocalHost(); //或者getHostName()\getHostAddress
		System.out.println(inet3);

例1如下

package wangluo;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;

import org.junit.Test;
//客户端发送信息给服务端，服务端显示在控制台上
public class TCPTest1 {
	@Test
	//客户端
	public void cilent(){
		Socket socket = null;
		OutputStream os = null;
		try {
			InetAddress inet = InetAddress.getByName("192.168.246.1");
			socket = new Socket(inet,8899);
			
			
			os = socket.getOutputStream();
			os.write(("你好，我叫王子璇").getBytes());
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(os != null){
				try {
					os.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
			if(socket != null){
				try {
					socket.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	
	@Test
	//服务端
	public void server(){
		ServerSocket ss = null;
		Socket socket = null;
		InputStream is = null;
		
		//不建议这样写，可能会有点乱码
//		byte[] buffer = new byte[20];
//		int len;
//		while((len = is.read(buffer)) != -1){
//			String str = new String(buffer,0,len);
//			System.out.println(str);
//					
//		}
		ByteArrayOutputStream baos = null;
		try {
			ss = new ServerSocket(8899);
			socket = ss.accept();
			is = socket.getInputStream();
			baos = new ByteArrayOutputStream();
			byte[] buffer = new byte[5];
			int len;
			while ((len = is.read(buffer)) != -1) {
				baos.write(buffer, 0, len);
			}
			System.out.println(baos.toString());
			
			System.out.println("收到了来自于" + socket.getInetAddress().getHostAddress() + "的数据");
		} catch (Exception e) {
			e.printStackTrace();
			// 关闭资源
		}finally{
			if(baos != null){
				try {
					baos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
			if(socket != null){
				try {
					socket.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
			if(ss != null){
				try {
					ss.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}

	}
}

例二

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;

import org.junit.Test;


// 客户端将文件发给服务端，服务端保存到本地,并返回发送成功给客户端
// 这里涉及到的异常应该使用try-catch-finally
public class TCPTest2 {
	
	@Test
	public void cilent() throws IOException{
		Socket socket = new Socket(InetAddress.getByName("192.168.246.1"),9090);
		// 输出流
		OutputStream os = socket.getOutputStream();
		// 输入流
		FileInputStream fis = new FileInputStream(new File("1.jpg"));
		
		byte[] buffer = new byte[1024];
		int len;
		while ((len = fis.read(buffer)) != -1){
			os.write(buffer,0,len);
		}
		socket.shutdownInput();
		// 接受来自于服务器的数据 
		InputStream is = socket.getInputStream();
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		byte[] bufferr = new byte[20];
		int len1;
		while((len1 = is.read(bufferr)) != -1){
			baos.write(buffer,0,len);
			
		}
		System.out.println(baos.toString());
		
		fis.close();
		os.close();
		socket.close();
		
		
		
	}

	
	@Test
	public void server() {
		Socket socket = null;
		InputStream is = null;
		FileOutputStream fos = null;
		try {
			ServerSocket ss = new ServerSocket(9090);
			socket = ss.accept();
			is = socket.getInputStream();
			
			fos = new FileOutputStream(new File("5.jpg"));
			
			byte[] buffer = new byte[1024];
			int len;
			while((len = is.read(buffer)) != -1){
				fos.write(buffer,0,len);
			}
			// 服务器端给客户端反馈，
			OutputStream os = socket.getOutputStream();
			os.write("你好美女，我收到照片了".getBytes());
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if (fos != null){
				try {
					fos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
			if(socket != null){
				try {
					socket.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	
}