tcp/ip 网络编程 socket

2/10/2017来源:ASP.NET技巧人气:1125

一、使用tcp协议实现client向server发送数据

//TCP编程例一:客户端给服务端发送信息。服务端输出此信息到控制台上
//网络编程实际上就是Socket的编程
public class TestTCP1 {

	// 客户端
	@Test
	public void client() {
		Socket socket = null;
		OutputStream os = null;
		try {
			// 1.创建一个Socket的对象,通过构造器指明服务端的ip地址,以及其接收程序的端口号
			socket = new Socket(InetAddress.getByName("127.0.0.1"), 9090);
			// 2.getOutputStream():发送数据,方法返回OutputStream的对象
			os = socket.getOutputStream();
			// 3.具体的输出过程
			os.write("我是客户端,请多关照".getBytes());
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.PRintStackTrace();
		} finally {
			// 4.关闭相应的流和Socket对象
			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();
				}

			}
		}

	}

	// 服务端
	@Test
	public void server() {
		ServerSocket ss = null;
		Socket s = null;
		InputStream is = null;
		try {
			// 1.创建一个ServerSocket的对象,通过构造器指明自身的端口号
			ss = new ServerSocket(9090);
			// 2.调用其accept()方法,返回一个Socket的对象
			s = ss.accept();
			// 3.调用Socket对象的getInputStream()获取一个从客户端发送过来的输入流
			is = s.getInputStream();
			// 4.对获取的输入流进行的操作
			byte[] b = new byte[20];
			int len;
			while ((len = is.read(b)) != -1) {
				String str = new String(b, 0, len);
				System.out.print(str);
			}
			System.out.println("收到来自于" + s.getInetAddress().getHostAddress()
					+ "的连接");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			// 5.关闭相应的流以及Socket、ServerSocket的对象
			if (is != null) {
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}

			}
			if (s != null) {
				try {
					s.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();
				}

			}
		}
	}
}
二、在一的基础上实现server向client返回数据

//TCP编程例二:客户端给服务端发送信息,服务端将信息打印到控制台上,同时发送“已收到信息”给客户端
public class TestTCP2 {
	//客户端
	@Test
	public void client(){
		Socket socket = null;
		OutputStream os = null;
		InputStream is = null;
		try {
			socket = new Socket(InetAddress.getByName("127.0.0.1"),8989);
			os = socket.getOutputStream();
			os.write("我是客户端".getBytes());
			//shutdownOutput():执行此方法,显式的告诉服务端发送完毕!
			socket.shutdownOutput();
			is = socket.getInputStream();
			byte[] b = new byte[20];
			int len;
			while((len = is.read(b)) != -1){
				String str = new String(b,0,len);
				System.out.print(str);
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				
			}
			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();
				}
				
			}
		}
		
		
	}
	//服务端
	@Test
	public void server(){
		ServerSocket ss = null;
		Socket s = null;
		InputStream is = null;
		OutputStream os = null;
		try {
			ss = new ServerSocket(8989);
			s = ss.accept();
			is = s.getInputStream();
			byte[] b = new byte[20];
			int len;
			while((len = is.read(b)) != -1){
				String str = new String(b,0,len);
				System.out.print(str);
			}
			os = s.getOutputStream();
			os.write("我已收到你的情意".getBytes());
			
		} 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(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				
			}
			if(s != null){
				try {
					s.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();
				}
				
			}
		}
		
	}
}
三、使用流,client向server发送文件

//TCP编程例三:从客户端发送文件给服务端,服务端保存到本地。并返回“发送成功”给客户端。并关闭相应的连接。
//如下的程序,处理异常时,要使用try-catch-finally!!本例仅为了书写方便~
public class TestTCP3 {
	@Test
	public void client()throws Exception{
		//1.创建Socket的对象
		Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), 9898);
		//2.从本地获取一个文件发送给服务端
		OutputStream os = socket.getOutputStream();
		FileInputStream fis = new FileInputStream(new File("1.jpg"));
		byte[] b = new byte[1024];
		int len;
		while((len = fis.read(b)) != -1){
			os.write(b,0,len);
		}
		socket.shutdownOutput();
		//3.接收来自于服务端的信息
		InputStream is = socket.getInputStream();
		byte[] b1 = new byte[1024];
		int len1;
		while((len1 = is.read(b1)) != -1){
			String str = new String(b1,0,len1);
			System.out.print(str);
		}
		//4.关闭相应的流和Socket对象
		is.close();
		os.close();
		fis.close();
		socket.close();
	}
	@Test
	public void server() throws Exception{
		//1.创建一个ServerSocket的对象
		ServerSocket ss = new ServerSocket(9898);
		//2.调用其accept()方法,返回一个Socket的对象
		Socket s = ss.accept();
		//3.将从客户端发送来的信息保存到本地
		InputStream is = s.getInputStream();
		FileOutputStream fos = new FileOutputStream(new File("3.jpg"));
		byte[] b = new byte[1024];
		int len;
		while((len = is.read(b)) != -1){
			fos.write(b, 0, len);
		}
		System.out.println("收到来自于" + s.getInetAddress().getHostAddress() + "的文件");
		//4.发送"接收成功"的信息反馈给客户端
		OutputStream os = s.getOutputStream();
		os.write("你发送的图片我已接收成功!".getBytes());
		//5.关闭相应的流和Socket及ServerSocket的对象
		os.close();
		fos.close();
		is.close();
		s.close();
		ss.close();
	}
}