【JavaNET】Java网路编程(3)

前言：

本文内容：TCP文件上传实现、初识Tomcat、UDP消息发送

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TCP文件上传实现

文件上传

客户端：

package com.jokerdig.netDemo;

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

/**
 * @author Joker大雄
 * @data 2021/9/3 - 19:04
 **/
//输出端
public class TcpDemo02 {
    public static void main(String[] args) throws Exception{
        //创建一个Socket连接
        Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), 9000);
        //创建一个输出流
        OutputStream out = socket.getOutputStream();
        //文件流
        FileInputStream fileInputStream = new FileInputStream(new File("OIP.jpg"));
        //写出文件
        byte[] buffer = new byte[1024];
        int len;
        while((len=fileInputStream.read(buffer))!=-1){
            out.write(buffer,0,len);
        }

        //通知服务器，已经传输完了
        socket.shutdownOutput();//传输完毕

        //确定服务器接收完毕，才能断开连接
        InputStream inputStream = socket.getInputStream();
        //String byte[]
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] bytes = new byte[2014];
        int len1;
        while((len1=inputStream.read(bytes))!=-1){
            byteArrayOutputStream.write(bytes,0,len1);
        }
        System.out.println(byteArrayOutputStream.toString());
        //关闭资源
        fileInputStream.close();
        out.close();
        socket.close();

    }
}

服务端：

package com.jokerdig.netDemo;

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

/**
 * @author Joker大雄
 * @data 2021/9/2 - 19:33
 **/
//服务端
public class TcpServerDemo {
    public static void main(String[] args) {
        ByteArrayOutputStream byteStream = null;
        InputStream inputStream = null;
        ServerSocket serverSocket = null;
        Socket socket = null;
        try {
            //我得有一个地址
            serverSocket = new ServerSocket(9988);
            //等待客户端连接过来
            socket = serverSocket.accept();
            //读取客户端消息
            inputStream = socket.getInputStream();
        /*    int len;
            while((len=inputStream.read(buffer))!=1){
                String msg=  new String(buffer,0,len);
                System.out.println(msg);
                //这样中文进来会乱码
            }
         */
            //管道流
            byteStream = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int len;
            while ((len = inputStream.read(buffer)) != -1) {
                byteStream.write(buffer, 0, len);
            }
            System.out.println(byteStream.toString());
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                //释放资源
                if (byteStream != null) {
                    byteStream.close();
                }
                if (inputStream != null) {
                    inputStream.close();
                }
                if (socket != null) {
                    socket.close();
                }
                if (serverSocket != null) {
                    serverSocket.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

初识Tomcat

Tomcat下载

服务端

• 自定义S
• Tomcat服务器

客户端

• 自定义C
• 浏览器B

解决服务器运行乱码：

​ Tomcat安装目录>conf>logging文件

#将该处UTF-8改为GBK
java.util.logging.ConsoleHandler.level = FINE
java.util.logging.ConsoleHandler.formatter = org.apache.juli.OneLineFormatter
java.util.logging.ConsoleHandler.encoding = GBK

UDP消息发送

发短信，不用连接，需要知道对方的地址。

发送端：

package com.jokerdig.netDemo;

import java.io.IOException;
import java.net.*;

/**
 * @author Joker大雄
 * @data 2021/9/3 - 20:01
 **/
//不需要连接服务器
public class UdpDemo3 {
    public static void main(String[] args) throws IOException {
        //建立一个socket
        DatagramSocket datagramSocket = new DatagramSocket();
        //建个包
        String manage="你好，服务器！";
        //发送的地址
        InetAddress localhost = InetAddress.getByName("localhost");
        int port =9090;
        //数据 数据的长度起始，发送给谁
        DatagramPacket packet = new DatagramPacket(manage.getBytes(),0, manage.getBytes().length, localhost, port);
        //发送包
        datagramSocket.send(packet);
        //释放资源
        datagramSocket.close();
    }
}

接收端：

package com.jokerdig.netDemo;

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

/**
 * @author Joker大雄
 * @data 2021/9/3 - 20:08
 **/
//还要等待客户端的连接
public class UdpDemo3_1 {
    public static void main(String[] args) throws IOException {
        //开放端口
        DatagramSocket socket = new DatagramSocket(9090);
        //接收数据包
        byte[] buffer = new byte[1024];
        int len;
        DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
        socket.receive(packet);//阻塞数据
        System.out.println(packet.getAddress().getHostAddress());
        System.out.println(new String(packet.getData(),0,packet.getLength()));
        //释放资源
        socket.close();
    }
}