java网络编程--3 TCP

1.6、TCP

客户端

连接服务器 Socket
发送消息

package com.ssl.lesson02;


import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;

//客户端
public class TcpClientDemo01 {
    public static void main(String[] args) {
        Socket socket = null;
        OutputStream os = null;

        try {
            //1.要知道服务器的地址，端口号
            InetAddress serverIP = InetAddress.getByName("127.0.0.1");
            int port = 9999;
            //2.创建一个socket连接

            socket = new Socket(serverIP,port);

            //3.发送消息，IO流
            os = socket.getOutputStream();
            os.write("你瞅啥".getBytes());


        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if(os!=null){
                try {
                    os.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }

            if (socket!=null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }

    }
}

服务端

建立服务的端口ServerSocket
等待用户连接accept
接收用的消息

package com.ssl.lesson02;


import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

//服务端
public class TcpServicerDemo01 {
    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        Socket socket = null;
        InputStream is = null;
        ByteArrayOutputStream baos = null;
        try {
            //1.我得有一个地址，服务插槽
            serverSocket = new ServerSocket(9999);
            while(true) {

                //2.等待客户端连接过来
                socket = serverSocket.accept();
                //3.读取客户端的消息
                is = socket.getInputStream();
                //初学者读取方式
            /*  会出现乱码
            byte[] buffer = new byte[1024];
            int len;
            while((len=is.read(buffer))!=-1){
                String msg =new String(buffer,0,len);
                System.out.println(msg);
            }
            */
                //管道流
                baos = new ByteArrayOutputStream();
                byte[] buffer = new byte[1024];
                int len;
                while ((len = is.read(buffer)) != -1) {
                    baos.write(buffer, 0, len);
                }
                System.out.println(baos.toString());
            }

        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            //关闭资源流
            if(baos!=null){
                try {
                    baos.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            if(is!=null){
                try {
                    is.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            if(socket!=null){
                try {
                    socket.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            if(serverSocket != null){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }

        }

    }
}

文件上传

客户端：

package com.ssl.lesson02;

import java.io.*;
import java.net.InetAddress;
import java.net.Socket;

public class TcpClientDemo02 {
    public static void main(String[] args) throws Exception{
        //1.创建一个Socket连接
        Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9000);
        //2.创建一个输出流
        OutputStream os = socket.getOutputStream();
        //3.文件流，读取文件
        FileInputStream fis = new FileInputStream(new File("1.jpg"));
        //4.写出文件
        byte[] buffer = new byte[1024];
        int len;
        while((len=fis.read(buffer))!=-1){
            os.write(buffer,0,len);
        }
        //通知服务器我已经结束了
        socket.shutdownOutput();  //我已经传输完了

        //确定服务器接收完毕，才能够断开连接
        InputStream is = socket.getInputStream();
        //String byte[]
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer2 = new byte[1024];
        int len2;
        while((len2=is.read(buffer2))!=-1){
            baos.write(buffer2,0,len2);
        }

        System.out.println(baos.toString());

        //5.关闭资源
        baos.close();
        is.close();
        fis.close();
        os.close();
        socket.close();
    }
}

服务端：

package com.ssl.lesson02;

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

public class TcpServicerDemo02 {
    public static void main(String[] args) throws Exception{
        //1.创建服务
        ServerSocket serverSocket = new ServerSocket(9000);
        //2.监听客户端的连接
        Socket socket = serverSocket.accept();  //阻塞式监听，会一直等待客户端连接
        //3.获取输入流
        InputStream is = socket.getInputStream();
        //4.文件输出
        FileOutputStream fos = new FileOutputStream(new File("receive.png"));
        byte[] buffer = new byte[1024];
        int len;
        while((len=is.read(buffer))!=-1){
            fos.write(buffer,0,len);
        }
        //通知客户端，我接收完毕了
        OutputStream os = socket.getOutputStream();
        os.write("我接收完毕了,可以断开了".getBytes());

        //5.关闭输入输出
        os.close();
        fos.close();
        is.close();
        socket.close();
        serverSocket.close();

    }

}