網路程式設計實戰講解

阿新 • • 發佈：2021-10-03

網路程式設計實戰講解

TCP實現聊天

客戶端

package com.example.quickstart;

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

//客戶端
public class TCPClient {
    public static void main(String[] args) {
        Socket socket=null;
        OutputStream outputStream=null;

        try {
            //要知道伺服器的地址
            InetAddress inetAddress = InetAddress.getByName("127.0.0.1");
            int port=8888;//埠號
            //建立一個socket連線
            socket = new Socket(inetAddress, port);
            //傳送訊息 IO流
            outputStream = socket.getOutputStream();
            outputStream.write("你好，歡迎來到我的世界".getBytes());
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                outputStream.close();
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

伺服器端

package com.example.quickstart;

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

public class TCPServer {
    public static void main(String[] args) {
        ServerSocket serverSocket=null;
        Socket accept=null;
        InputStream inputStream=null;
        ByteArrayOutputStream arrayOutputStream=null;

        //我得有一個地址
        try {
            serverSocket = new ServerSocket(8888);
            while(true){
                //等待客戶端連線過來
                accept = serverSocket.accept();
                //讀取客戶端的訊息
                inputStream = accept.getInputStream();
                //管道流
                arrayOutputStream = new ByteArrayOutputStream();
                byte[] buffer=new byte[1024];
                int len;
                while((len=inputStream.read(buffer))!=-1){
                    arrayOutputStream.write(buffer,0,len);
                }
                System.out.println(arrayOutputStream.toString());
            }

            /*byte[] bytes = new byte[1024];//1k
            int len;
            while((len=inputStream.read(bytes))!=-1){
                String message = new String(bytes, 0, len);
                System.out.println(message);
            }*/
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                arrayOutputStream.close();
                inputStream.close();
                accept.close();
                serverSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

TCP檔案上傳實現

客戶端

package com.example.quickstart;

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

public class TCPUploadClient {
    public static void main(String[] args) {
        try {
            //建立一個Socket連線
            Socket socket = new Socket(InetAddress.getByName("localhost"), 9000);
            //建立一個輸出流
            OutputStream outputStream = socket.getOutputStream();
            //檔案輸入流-讀取檔案
            FileInputStream inputStream = new FileInputStream(new File("img1.webp"));
            //寫出檔案
            byte[] buffer=new byte[1024];
            int len;
            while((len=inputStream.read(buffer))!=-1){
                outputStream.write(buffer,0,len);
            }
            //通知伺服器我已經結束了
            socket.shutdownOutput();

            //確定伺服器接收完畢，才能斷開連線
            InputStream socketInputStream = socket.getInputStream();
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            byte[] buffer2 = new byte[2048];
            int len2;
            while((len2=socketInputStream.read(buffer2))!=-1){
                byteArrayOutputStream.write(buffer2,0,len2);
            }
            String message = byteArrayOutputStream.toString();
            System.out.println(message);

            //關閉資源
            byteArrayOutputStream.close();
            socketInputStream.close();
            inputStream.close();
            outputStream.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

伺服器端

package com.example.quickstart;

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

public class TCPUploadServer {
    public static void main(String[] args) {
        try {
            //建立服務
            ServerSocket serverSocket = new ServerSocket(9000);
            //監聽客戶端的連線
            Socket accept = serverSocket.accept();//阻塞式監聽，會一直等待客戶端連線
            //獲取輸入流
            InputStream inputStream = accept.getInputStream();
            //檔案輸出
            FileOutputStream outputStream = new FileOutputStream(new File("receive.webp"));
            byte[] buffer = new byte[1024];
            int len;
            while((len=inputStream.read(buffer))!=-1){
                outputStream.write(buffer,0,len);
            }
            //通知客戶端我接收完畢了
            OutputStream acceptOutputStream = accept.getOutputStream();
            acceptOutputStream.write("我接收完畢了，你可以斷開了".getBytes());

            //關閉資源
            outputStream.close();
            inputStream.close();
            accept.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

UDP訊息傳送

客戶端

package com.example.udp;

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

//不需要連線伺服器
public class UDPClientDemo1 {
    public static void main(String[] args) {
        try {
            //建立一個Socket
            DatagramSocket socket = new DatagramSocket();
            //建個包
            String message="你好，伺服器";
            byte[] messageBytes = message.getBytes();
            InetAddress localhost = InetAddress.getByName("localhost");//傳送給誰
            int port = 9090;//埠號
            DatagramPacket packet = new DatagramPacket(messageBytes,0,messageBytes.length,localhost,port);
            //傳送包
            socket.send(packet);

            //關閉流
            socket.close();
        } catch (SocketException | UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

伺服器端

package com.example.udp;

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

//還是要等待客戶端的連線
public class UDPServerDemo1 {
    public static void main(String[] args) {
        try {
            //開放埠
            DatagramSocket socket = new DatagramSocket(9090);
            //接收資料包
            byte[] buffer = new byte[1024];
            DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
            socket.receive(packet);//阻塞接收

            //輸出包裹資訊
            System.out.println(new String(packet.getData()));

            //關閉連線
            socket.close();
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

UDP連續傳送訊息

傳送方

package com.example.udp;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.*;

public class UDPSenderDemo1 {
    public static void main(String[] args) {
        try {
            DatagramSocket socket = new DatagramSocket(8888);

            //準備資料：控制檯讀取 System.in
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            while(true){
                String message = reader.readLine();
                byte[] messageBytes = message.getBytes();
                InetAddress localhost = InetAddress.getByName("localhost");
                DatagramPacket packet = new DatagramPacket(messageBytes, 0, messageBytes.length, localhost, 6666);
                socket.send(packet);
                if("bye".equalsIgnoreCase(message)){
                    break;
                }
            }

            socket.close();
        } catch (SocketException | UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

接收方

package com.example.udp;

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

public class UDPReceiveDemo1 {
    public static void main(String[] args) {
        try {
            DatagramSocket socket = new DatagramSocket(6666);

            while(true){
                //準備接收包裹
                byte[] buffer = new byte[1024];
                DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);
                socket.receive(packet);
                byte[] data = packet.getData();
                String message = new String(data, 0, data.length);
                System.out.println(message);
                if("bye".equalsIgnoreCase(message)){
                    break;
                }
            }

            socket.close();
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

UDP多執行緒線上諮詢

傳送方

package com.example.udp;

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

public class ChatSender implements Runnable {
    DatagramSocket socket=null;
    BufferedReader reader=null;
    private String toIP;
    private int toPort;
    private int fromPort;

    public ChatSender(String toIP, int toPort, int fromPort) {
        this.toIP = toIP;
        this.toPort = toPort;
        this.fromPort = fromPort;
        try {
            socket=new DatagramSocket(fromPort);
            reader=new BufferedReader(new InputStreamReader(System.in));

        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while(true){
            try {
                String data = reader.readLine();
                byte[] dataBytes = data.getBytes();
                DatagramPacket packet = new DatagramPacket(dataBytes, 0, dataBytes.length, new InetSocketAddress(toIP, toPort));
                socket.send(packet);
                if("bye".equalsIgnoreCase(data)){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

接收方

package com.example.udp;

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

public class ChatReceiver implements Runnable {
    DatagramSocket socket=null;
    private int port;

    public ChatReceiver(int port) {
        this.port = port;
        try {
            socket=new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        byte[] buffer=null;
        DatagramPacket packet=null;
        while(true){
            try {
                buffer=new byte[1024];
                packet = new DatagramPacket(buffer, 0, buffer.length);
                socket.receive(packet);
                byte[] data = packet.getData();
                String message = new String(data);
                System.out.println("fromIP: "+packet.getAddress()+", fromMessage: "+message);
                if("bye".equalsIgnoreCase(message)){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

學生：即是傳送方也是接收方

package com.example.udp;

public class ChatStudent {
    public static void main(String[] args) {
        //開啟兩個執行緒
        new Thread(new ChatSender("localhost",6666,7777)).start();
        new Thread(new ChatReceiver(8888)).start();
    }
}

老師：即是傳送方也是接收方

package com.example.udp;

public class ChatTeacher {
    public static void main(String[] args) {
        new Thread(new ChatSender("localhost",8888,9999)).start();
        new Thread(new ChatReceiver(6666)).start();
    }
}

URL下載網路資源

爬取網易雲音樂

package com.example.url;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

//下載地址：http://localhost:8080/favicon.ico
//ps：需開啟tomcat
public class URLDownload {
    public static void main(String[] args) {
        try {
            //下載地址
            URL url = new URL("https://m801.music.126.net/20211003095941/a0a7f59871fb88d6492845ca20aac658/jdyyaac/obj/w5rDlsOJwrLDjj7CmsOj/11062312467/6a10/8c90/0eaf/e12ae5442e789a1e2215ddeae103befb.m4a");
            //連線到這個資源
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            InputStream inputStream = connection.getInputStream();
            FileOutputStream fileOutputStream = new FileOutputStream("奔流.m4a");
            byte[] buffer = new byte[1024];
            int len;
            while((len=inputStream.read(buffer))!=-1){
                fileOutputStream.write(buffer,0,len);
            }
            fileOutputStream.close();
            inputStream.close();
            connection.disconnect();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

【狂神說Java】網路程式設計實戰講解_嗶哩嗶哩_bilibili

作者：(x²+y²-1)³=x²y³ 出處：http://www.cnblogs.com/yts-helloworld/

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