Java學習筆記53（網路編程：TCP協議案例），學習筆記tcp

Java學習筆記53（網路編程：TCP協議案例），學習筆記tcp

簡易的案例

用戶端：

package demo;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.Socket;public class TCPClient {    public static void main(String[] args) throws IOException {        Socket socket = new Socket("127.0.0.1", 7000);        OutputStream out = socket.getOutputStream();        out.write("hello".getBytes());        InputStream in = socket.getInputStream();        byte[] data = new byte[1024];        int len = in.read(data);        System.out.println(new String(data, 0, len));        socket.close();    }}

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伺服器端：

package demo;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;public class TCPServer {    public static void main(String[] args) throws IOException {        ServerSocket server = new ServerSocket(7000);        Socket socket = server.accept();        InputStream in = socket.getInputStream();        byte[] data = new byte[1024];        int len = in.read(data);        System.out.println(new String(data, 0, len));        OutputStream out = socket.getOutputStream();        out.write("收到".getBytes());        socket.close();        server.close();    }}

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先啟動伺服器端，再啟動用戶端，伺服器端列印:hello，然後用戶端列印:收到

注意區分這裡的流對象

 

接下來在這個案例基礎上做一個圖片上傳案例

圖片上傳的本質就是檔案複製

 

用戶端：

package demo1;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.Socket;public class TCPClient {    public static void main(String[] args) throws IOException {        Socket socket = new Socket("127.0.0.1", 7000);        OutputStream out = socket.getOutputStream();        FileInputStream fis = new FileInputStream("d:\\666.jpeg");        int len = 0;        byte[] bytes = new byte[1024];        while ((len = fis.read(bytes)) != -1) {            out.write(bytes, 0, len);        }        socket.shutdownOutput();        // 伺服器端讀不到-1，不會終止，調用這個方法可以終止        InputStream in = socket.getInputStream();        len = in.read(bytes);        System.out.println(new String(bytes, 0, len));        fis.close();        socket.close();    }}

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伺服器端：

package demo1;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.net.ServerSocket;import java.net.Socket;import java.util.Random;public class TCPServer {    public static void main(String[] args) throws IOException {        ServerSocket server = new ServerSocket(7000);        Socket socket = server.accept();        InputStream in = socket.getInputStream();        File upload = new File("d:\\upload");        if (!upload.exists()) {            upload.mkdirs();        }        String filename = System.currentTimeMillis() + new Random().nextInt(999999) + ".jpeg";        FileOutputStream fos = new FileOutputStream(upload + File.separator + filename);        // 這裡是處理圖片重名的問題        byte[] bytes = new byte[1024];        int len = 0;        while ((len = in.read(bytes)) != -1) {            fos.write(bytes, 0, len);        }        socket.getOutputStream().write("上傳成功".getBytes());        fos.close();        socket.close();        server.close();    }}

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如果多個用戶端一起上傳，就需要多線程的技術，每個用戶端佔一個線程

用戶端不需要修改

伺服器端：

package demo1;import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;public class TCPServer {    public static void main(String[] args) throws IOException {        ServerSocket server = new ServerSocket(7000);        while (true) {            Socket socket = server.accept();            new Thread(new Upload(socket)).start();        }    }}

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package demo1;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.net.ServerSocket;import java.net.Socket;import java.util.Random;public class Upload implements Runnable {    private Socket socket;    public Upload(Socket socket) {        this.socket = socket;    }    public void run() {        try {            InputStream in = socket.getInputStream();            File upload = new File("d:\\upload");            if (!upload.exists()) {                upload.mkdirs();            }            String filename = System.currentTimeMillis() + new Random().nextInt(999999) + ".jpeg";            FileOutputStream fos = new FileOutputStream(upload + File.separator + filename);            // 這裡是處理圖片重名的問題            byte[] bytes = new byte[1024];            int len = 0;            while ((len = in.read(bytes)) != -1) {                fos.write(bytes, 0, len);            }            socket.getOutputStream().write("上傳成功".getBytes());            fos.close();            socket.close();        } catch (IOException ex) {            System.out.println(ex);        }    }}

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