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) {

}
}