tcp/ip 网络编程 socket

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();	}}