java中TCP总结

先看一张图，画的很挫，将就看。

TCP 客户端与服务端通信时，是服务端会拿到客户端的socket进行通信。

TCP就相当于以前的座机，有一个听筒和一个话筒，A用话筒说话，B用听筒听。

下面讲讲java中TCP的使用以及步骤。

TCP客户端步骤：

　　1.建立Socket服务，并确定IP和Port

　　2.通过socket服务获取输入流或输出流。

　　3.通输入或输出流操作数据。

TCP服务端的步骤：

　　1.用ServerSocket来监听Port

　　2.用accept获取客户端的Socket

　　3.通客户端的Socket来获取输入和输出流。

　　4.通过数据流传输。

用一个简单实例演示：

package com.core.net;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

class TcpClient{

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

		Socket s = new Socket("localhost", 10004);

		OutputStream out = s.getOutputStream();

		out.write("tcp come ...".getBytes());

		s.close();
	}
}
class TcpServer{

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

		ServerSocket ss = new ServerSocket(10004);

		Socket s = ss.accept();

		String ip = s.getInetAddress().getHostAddress();
		System.out.println(ip+".....connect");

		InputStream in = s.getInputStream();

		byte[] buf = new byte[1024];

		int len = in.read(buf);

		System.out.println(new String(buf,0,len));

		s.close();
		ss.close();

	}
}
public class TcpDemo {

	public static void main(String[] args) {

	}
}

这个实例只是客服端发送数据，服务器接收数据。

下面是一个例子是客服端发送数据，服务器发送数据。

package com.core.net;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

class Client2{

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

		Socket socket = new Socket("localhost", 10004);

		OutputStream out =  socket.getOutputStream();

		out.write("服务端，你好".getBytes());

		InputStream in = socket.getInputStream();

		byte[] buf = new byte[1024];

		int len = in.read(buf);

		System.out.println(new String(buf,0,len));

		socket.close();
	}
}
class Server2{

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

		ServerSocket ss = new ServerSocket(10004);

		Socket s = ss.accept();

		InputStream in = s.getInputStream();

		byte[] buf = new byte[1024];

		int len = in.read(buf);

		System.out.println(new String(buf,0,len));

		OutputStream out = s.getOutputStream();

		Thread.sleep(10000);

		out.write("客服端，你好".getBytes());

		s.close();

		ss.close();
	}
}
public class TcpDemo2 {

	public static void main(String[] args) {

	}
}

最后一个例子是服务端为大写转换器，客服端输入数据，服务端将输入的数据转换大写。

package com.core.net;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

class TransClient{

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

		Socket socket = new Socket("localhost", 10005);

		//键盘输入
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		//socket输入流
		BufferedReader bufin = new BufferedReader(new InputStreamReader(socket.getInputStream()));
		//socket输出流
		BufferedWriter bufout = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));

		String line = null;
		while((line = reader.readLine())!=null){

			if("over".equals(line))
				break;
			bufout.write(line);
			bufout.newLine();//要注意 "\r\n"
			bufout.flush();

			String str = bufin.readLine();
			System.out.println("server:"+str);

		}
		reader.close();
		socket.close();

	}
}

class TransServer{

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

		ServerSocket ss = new ServerSocket(10005);

		     Socket s = ss.accept();
		     String ip = s.getInetAddress().getHostAddress();
		     System.out.println(ip+"......connection");
		 BufferedReader reader = new BufferedReader(new InputStreamReader(s.getInputStream()));
		 BufferedWriter out = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
		 String line = null;
		 while((line = reader.readLine())!=null){

			 System.out.println(line);
			 out.write(line.toUpperCase());
			 out.newLine();
			 out.flush();
		 }
		 s.close();
		 ss.close();
	}
}
public class TransDemo {

	public static void main(String[] args) {

	}
}