利用JAVA的服务器客户端来实现网内下载

傷城~ 2024-04-17 05:53 53阅读 0赞

**利用服务器客户端的socket来实现下载功能**

服务器端代码：
    
        package com;import java.io.BufferedReader;
        import java.io.File;
        import java.io.FileInputStream;
        import java.io.IOException;
        import java.io.InputStream;
        import java.io.InputStreamReader;
        import java.io.OutputStream;
        import java.io.OutputStreamWriter;
        import java.net.ServerSocket;
        import java.net.Socket;public class Server {
        	public static void main(String[] args) {
        		ServerSocket server = null;
        		Socket socket = null;
        		File file = new File("E:\file");
        		File[] files = file.listFiles();    OutputStream os = null;
            OutputStreamWriter osw = null;
        
            InputStream is = null;
            InputStreamReader isr = null;
            BufferedReader br = null;
        
            FileInputStream fis = null;
            try {
                //创建服务器端口
                server = new ServerSocket(7777);
                //使Socket处于阻塞状态
                socket = server.accept();
                //服务器可以接受客户端发来的信息，也可以传输文件。所以定义这些IO流
                os = socket.getOutputStream();
                osw = new OutputStreamWriter(os, "utf-8");
                is = socket.getInputStream();
                isr = new InputStreamReader(is, "utf-8");
                br = new BufferedReader(isr);
        
                int bookId = -1;
                for (int i = 1; i <= files.length; i++) {
                    osw.write(i + "." + files[i - 1].getName() + "\n");
                    osw.flush();
                }
                osw.write("File Exit" + "\n");
                osw.flush();
        
                // 接收需要下载的书籍编号
                bookId = Integer.parseInt(br.readLine());
                fis = new FileInputStream(files[bookId - 1]);
                byte[] buf = new byte[1024];
                int len = 0;
                osw.write(files[bookId - 1].getName() + "\n");
                osw.flush();
                while ((len = fis.read(buf)) > 0) {
                    os.write(buf, 0, len);
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                try {
                    fis.close();
                    br.close();
                    isr.close();
                    osw.close();
                    is.close();
                    os.close();
                    socket.close();
                    server.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }}
        ```
    客户端代码；
    
    
    package com;import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.net.Socket;
    import java.net.UnknownHostException;
    import java.util.Scanner;public class Client {public static void main(String[] args) {
        Socket socket = null;
        File dFile = new File("E:\\777");
    
        InputStream is = null;
        InputStreamReader isr = null;
        BufferedReader br = null;
    
        OutputStream os = null;
        OutputStreamWriter osw = null;
        Scanner scanner = new Scanner(System.in);
        FileOutputStream fos = null;
        try {
            // 接收服务器遍历后的文件
            socket = new Socket("127.0.0.1", 7777);
            is = socket.getInputStream();
            isr = new InputStreamReader(is, "utf-8");
            br = new BufferedReader(isr);
            
            os = socket.getOutputStream();
            osw = new OutputStreamWriter(os,"utf-8");
            int bookId = 0;
    
            while (true) {
                String str = br.readLine();
                if ("File Exit".equals(str)) {
                    break;
                }
                System.out.println(str);
            }
    
            System.out.println("<");
            bookId = Integer.parseInt(scanner.nextLine());
            osw.write(bookId + "\n");
            osw.flush();
    
            String fileName = br.readLine();
            File file = new File(dFile, fileName);
            fos = new FileOutputStream(file);
            byte[] buf = new byte[1024];
            int len = 0;
    
            while ((len = is.read(buf)) > 0) {
                fos.write(buf, 0, len);
            }
            System.out.println("下载完成！！！");
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            try {
                fos.close();
                br.close();
                osw.close();
                isr.close();
                os.close();
                is.close();
                socket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    
    }}