简单网络编程、

UDP

receive类 

package udp;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class ReceiveDemo {
    public static void main(String[] args) throws IOException {
            //创建接收端的Socket对象（DatagramSocket)
            //DatagramSocket(int port )构造数据报套接字并将其绑定到本地主机上到指定端口
            DatagramSocket ds= new DatagramSocket(10086);

            //创建一个数据包，用于接收数据
            //Datagrampacket(byte[] buf , int length) 构造一个Datagrampacket 用于接收长度为length 的数据包

            byte[] bys = new byte[1024];
            DatagramPacket dp =new DatagramPacket(bys,bys.length);

            //调用DatagramSocket 对象的方法接收数据
            ds.receive(dp);

            //解析数据包，并把数据在控制台显示
            byte []  datas =dp.getData();
            String dataString = new String(datas,0,dp.getLength());
            System.out.println("数据是："+ dataString);

            //关闭接收端
            ds.close();


        }
}

send类

package udp;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class sendDemo {

    public static void main(String[] args) throws IOException {
        //创建发送端Socket对象（DatagramSocket)
        //DatagramSocket()构造数据包套接字并将其绑定本地主机上的任何可用端口
        DatagramSocket ds = new DatagramSocket();

        //创建数据，并将数据打包
        //DatagramPcacket (byte[] buf ,int lengtg ,InetAddress  address, int port)
        byte[] bye = "hello,udp,我来了".getBytes();
        int lengt = bye.length;
        InetAddress address = InetAddress.getByName("");//括号内加计算机名，或ip
        int port = 10086;
        DatagramPacket dp = new DatagramPacket(bye, lengt, address, port);

        //调用DatagramSocket对象的方法发送数据
        //void send (DatagramPacket p )从此套接字发送数据报包
        ds.send(dp);

        //关闭发送端
        //void close()关闭此数据报套接字
        ds.close();
    }
}

TCP

客户端

package Socket;

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

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //创建客户端Socket对象
        Socket s =new Socket("",10098);//""内加ip

        //获取输出流，写数据
        OutputStream os = s.getOutputStream();
        os.write("hello,tcp,我来了".getBytes());

        //接收服务器反馈
        InputStream is=s.getInputStream();
        byte [] bys =new byte[1024];
        int len=is.read(bys);
        String data  =new String(bys,0,len);
        System.out.println("客户端："+data);


        //释放资源
        s.close();
    }
}

服务端

package Socket;

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

public class ServerDemo {
    public static void main(String[] args) throws IOException {
        //创建服务器Socket对象
        ServerSocket ss =new ServerSocket(10098);

        //监听客户端连接，返回一个Socket对象
        Socket s =ss.accept();

        //获取输入流，读数据，并把数据显示在控制台
        InputStream is = s.getInputStream();
        byte [] bys =new byte[1024];
        int len =is.read(bys);
        String data =new String(bys,0,len);
        System.out.println("服务器:"+data);

        //给出反馈
        OutputStream os =s.getOutputStream();
        os.write("数据已收到".getBytes());

        //释放资源
        ss.close();

    }
}

通过tcp上传图片

客户端

package picture;

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

public class Client {

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

        System.out.println("上传图片客户端启动中...");
        //创建客户端Socket对象
        Socket s =new Socket("",10088);//""内加ip

        //获取输出流，写数据
        File picFile = new File("D:\sa\1.jpg");
        BufferedInputStream fis = new BufferedInputStream(new FileInputStream(picFile));

        //目的：Socket输出流  发送到服务端
        OutputStream os=s.getOutputStream();
        byte [] bys =new byte[1024];
        int len=0;

        while((len = fis.read(bys)) != -1)
        {
            os.write(bys, 0, len);
        }

        //服务端反馈
        //告诉服务端   图片发送完成，不要在等着读了
           s.shutdownOutput();

        //读取上传成功字样
        BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
        String info = in.readLine();
        System.out.println(info);

        //释放资源
        fis.close();
        s.close();
    }
}

服务端

package picture;

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

public class Server {
    public static void main(String[] args) throws IOException {

        System.out.println("上传图片服务端启动...");

        //创建服务器Socket对象
        ServerSocket ss =new ServerSocket(10088);

        //监听客户端连接，返回一个Socket对象
        Socket s =ss.accept();

        // 写图片数据到文件的输出流
        File dir = new File("D:\sa\photo");

        // 为了避免重名覆盖，通过给重名文件进行编号
        String ip = s.getInetAddress().getHostAddress();
        int count = 1;
        File picFile = new File(dir, ip + "(" + count + ")" + ".jpg");

        while (picFile.exists()) {
            count++;
            picFile = new File(dir, ip + "(" + count + ")" + ".jpg");
        }

        FileOutputStream fos = new FileOutputStream(picFile);

        //获取输入流，读数据，并把数据显示在控制台
        InputStream is = s.getInputStream();
        byte [] bys =new byte[1024];
        int len =0;

        while ((len = is.read(bys)) != -1) {
            fos.write(bys, 0, len);
        }

        // 给客户端一个回馈信息
        BufferedWriter out = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        out.write("上传成功！"); // 写完需要刷新一下，或者关闭流

        //释放资源
        out.close();
        fos.close();
        s.close();


    }
}