JAVA Sokcet(服务端)连接WebSocket个人总结

末蓝、 2022-08-18 11:55 8阅读 0赞

# JAVA Socket连接WebSocket个人总结 #

如果大家是Web项目的话就可以不用JAVA的Socket去进行连接客户端的WebSocket。因为javaee-api-7.0以上版本有对服务器端的WebSocket进行封装，通过启动服务就可以让网页轻松访问到连接。

我这里是用Java中的java.net.socket与之连接，这是一个比较复杂的服务器端，需要我们自己去封装一些与浏览器之间的操作。握手操作是建立连接的桥梁，然后建立起TCP通信，即可。

下面直接上代码吧

private int port = 8888;
    serverSocket = new ServerSocket(port);
    System.out.println("服务器启动");

定义端口，创建ServerSocket对象，这时服务就启动了。服务启动了，我们就要来接收客户端那边对我们的响应了。

socket = serverSocket.accept();
    //开启线程，接收不同的socket请求
    Thread workThread = new Thread(new Handler(socket));
    workThread.start();

我们同构accept()来接收响应，如果接收成功那么我们创建一个新的线程去操作它的具体内容。

//获取socket输入流信息
    InputStream in = socket.getInputStream();
    byte[] buf = new byte[1024];
    //读到字节（读取输入流数据到缓存）
    int len = in.read(buf, 0, 1024);
                    //读到字节数组（定义一个容纳数据大小合适缓存区）
                    byte[] res = new byte[len];
                    //将buf内中数据拷贝到res中
                    System.arraycopy(buf, 0, res, 0, len);
                    //打印res缓存内容
                    String key = new String(res);

if(!hasHandshake && key.indexOf("Key") > 0){
                        //握手
    //通过字符串截取获取key值
                        key = key.substring(0, key.indexOf("==") + 2);
                        key = key.substring(key.indexOf("Key") + 4, key.length()).trim();
                        //拼接WEBSOCKET传输协议的安全校验字符串
                        key+= "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
                        //通过SHA-1算法进行更新
                        MessageDigest md = MessageDigest.getInstance("SHA-1");  
                        md.update(key.getBytes("utf-8"), 0, key.length());
                        byte[] sha1Hash = md.digest();  
                        //进行Base64加密
                        sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();  
                        key = encoder.encode(sha1Hash);  
                        //服务器端返回输出内容
                        pw.println("HTTP/1.1 101 Switching Protocols");
                        pw.println("Upgrade: websocket");
                        pw.println("Connection: Upgrade");
                        pw.println("Sec-WebSocket-Accept: " + key);
                        pw.println();
                        pw.flush();

//将握手标志更新，只握一次
                        hasHandshake = true;
                        //服务器返回成功，---握手协议完成，进行TCP通信

这样就可以进行正常的交互了！

贴上源码：

package com.cx;
    
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.PrintWriter;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.nio.ByteBuffer;
    import java.nio.charset.Charset;
    import java.security.MessageDigest;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.swing.JTextArea;
    /**
      * @author(作者) :Cx
     */
    public class WebServer {
    	private int port = 8888;
        private ServerSocket serverSocket;
        private List<Handler> handlers = new ArrayList<Handler>();
        JTextArea text;//显示信息
     
        public WebServer(JTextArea text) throws IOException {
        	this.text = text;
            serverSocket = new ServerSocket(port);
            text.setText("WebSocket服务器已启动!\n");
            text.append("等待客户端连接...!\n");
        }
     
        public void service() {
            Socket socket = null;
            while (true) {
                try {
                	//接收socket请求
                    socket = serverSocket.accept();
                    //判断
                    if(handlers.size()>0){
                		for (Handler handler : handlers) {
                			if(handler.getSpeech()!=null){
                				handler.getSpeech().flag=false;
                			}
    					}
                		handlers.clear();
                	}
                    //开启线程，接收不同的socket请求
                    Handler handler = new Handler(socket);
                    handlers.add(handler);
                    Thread workThread = new Thread(handler);
                    workThread.start();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
     
        class Handler implements Runnable {
        	private Speech speech = new Speech();
            private Socket socket;
            private boolean hasHandshake = false;
            Charset charset = Charset.forName("UTF-8");  
            
            public Speech getSpeech(){
            	return this.speech;
            }
            
            public Handler(Socket socket) {
                this.socket = socket;
            }
     
            private PrintWriter getWriter(Socket socket) throws IOException {
                OutputStream socketOut = socket.getOutputStream();
                return new PrintWriter(socketOut, true);
            }
            public void run() {
                try {
                    System.out.println("New connection accepted"
                            + socket.getInetAddress() + ":" + socket.getPort());
                    text.append("New connection accepted!.."+socket.getInetAddress()+":"+socket.getPort()+"\n");
                    text.setCaretPosition(text.getText().length());
                    //获取socket输入流信息
                    InputStream in = socket.getInputStream();
                    //获取socket输出
                    PrintWriter pw = getWriter(socket);
                    //读入缓存(定义一个1M的缓存区)
                    byte[] buf = new byte[1024];
                    //读到字节（读取输入流数据到缓存）
                    int len = in.read(buf, 0, 1024);
                    //读到字节数组（定义一个容纳数据大小合适缓存区）
                    byte[] res = new byte[len];
                    //将buf内中数据拷贝到res中
                    System.arraycopy(buf, 0, res, 0, len);
                    //打印res缓存内容
                    String key = new String(res);
                    if(!hasHandshake && key.indexOf("Key") > 0){
                        //握手
                    	//通过字符串截取获取key值
                        key = key.substring(0, key.indexOf("==") + 2);
                        key = key.substring(key.indexOf("Key") + 4, key.length()).trim();
                        //拼接WEBSOCKET传输协议的安全校验字符串
                        key+= "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
                        //通过SHA-1算法进行更新
                        MessageDigest md = MessageDigest.getInstance("SHA-1");  
                        md.update(key.getBytes("utf-8"), 0, key.length());
                        byte[] sha1Hash = md.digest();  
                        //进行Base64加密
                        sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();  
                        key = encoder.encode(sha1Hash);  
                        //服务器端返回输出内容
                        pw.println("HTTP/1.1 101 Switching Protocols");
                        pw.println("Upgrade: websocket");
                        pw.println("Connection: Upgrade");
                        pw.println("Sec-WebSocket-Accept: " + key);
                        pw.println();
                        pw.flush();
                        //将握手标志更新，只握一次
                        hasHandshake = true;
                        //服务器返回成功，---握手协议完成，进行TCP通信
                        //进行语音交互
    					//当时做语音时用到的
                        speech.verifySocket(this);
                        //----------------------以下是获取到浏览器发送的消息--------
                        //接收数据
                        byte[] first = new byte[1];
                    	//这里会阻塞
                        int read = in.read(first, 0, 1);
                        //读取第一个字节是否有值,开始接收数据
                        while(read > 0){
                        	//让byte和十六进制做与运算（二进制也就是11111111）
                        	//获取到第一个字节的数值
                            int b = first[0] & 0xFF;
                            //1为字符数据，8为关闭socket（只要低四位的值判断）
                            byte opCode = (byte) (b & 0x0F);
                            if(opCode == 8){
                                socket.getOutputStream().close();
                                break;
                            }
                            b = in.read();
                            //只能描述127
                            int payloadLength = b & 0x7F;
                            if (payloadLength == 126) {
                                byte[] extended = new byte[2];
                                in.read(extended, 0, 2);
                                int shift = 0;
                                payloadLength = 0;
                                for (int i = extended.length - 1; i >= 0; i--) {
                                    payloadLength = payloadLength + ((extended[i] & 0xFF) << shift);
                                    shift += 2;
                                }
                            } else if (payloadLength == 127) {
                                byte[] extended = new byte[8];
                                in.read(extended, 0, 8);
                                int shift = 0;
                                payloadLength = 0;
                                for (int i = extended.length - 1; i >= 0; i--) {
                                    payloadLength = payloadLength + ((extended[i] & 0xFF) << shift);
                                    shift += 8;
                                }
                            }
                            //掩码
                            byte[] mask = new byte[4];
                            in.read(mask, 0, 4);
                            int readThisFragment = 1;
                            ByteBuffer byteBuf = ByteBuffer.allocate(payloadLength + 30);
                            byteBuf.put("浏览器: ".getBytes("UTF-8"));
                            while(payloadLength > 0){
                                 int masked = in.read();
                                 masked = masked ^ (mask[(int) ((readThisFragment - 1) % 4)] & 0xFF);
                                 byteBuf.put((byte) masked);
                                 payloadLength--;
                                 readThisFragment++;
                            }
                            byteBuf.flip();
                            //将内容返回给客户端
                            responseClient(byteBuf, true);
                            //打印内容
                            printRes(byteBuf.array());
                            in.read(first, 0, 1);
                        }
                    }
                    in.close();
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                	System.out.println("*********************废弃Socket回收阶段******************！");
                    try {
                        if (socket != null){
                            socket.close();
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
     
            public void responseClient(ByteBuffer byteBuf, boolean finalFragment) throws IOException {
                OutputStream out = socket.getOutputStream();
                int first = 0x00;
                //是否是输出最后的WebSocket响应片段
                    if (finalFragment) {
                        first = first + 0x80;
                        first = first + 0x1;
                    }
                    out.write(first);
                    if (byteBuf.limit() < 126) {
                        out.write(byteBuf.limit());
                    } else if (byteBuf.limit() < 65536) {
                    out.write(126);
                    out.write(byteBuf.limit() >>> 8);
                    out.write(byteBuf.limit() & 0xFF);
                    } else {
                    // Will never be more than 2^31-1
                    out.write(127);
                    out.write(0);
                    out.write(0);
                    out.write(0);
                    out.write(0);
                    out.write(byteBuf.limit() >>> 24);
                    out.write(byteBuf.limit() >>> 16);
                    out.write(byteBuf.limit() >>> 8);
                    out.write(byteBuf.limit() & 0xFF);
                    }
                    // Write the content
                    out.write(byteBuf.array(), 0, byteBuf.limit());
                    out.flush();
            }
             
            private void printRes(byte[] array) {
                ByteArrayInputStream  byteIn = new ByteArrayInputStream(array);
                InputStreamReader reader = new InputStreamReader(byteIn, charset.newDecoder());
                int b = 0;
                String res = "";
                try {
                    while((b = reader.read()) > 0){
                        res += (char)b;
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                System.out.println(res);
            }
        }
    }

package com.cx;
    
    import java.nio.ByteBuffer;
    
    import com.cx.WebServer.Handler;
    
    /**
      * @author(作者) :Cx
     */
    public class Speech {
    	Boolean flag = true;
    	//加上锁，只允许一个网页连接进行交互。
    	public synchronized   void verifySocket(Handler handle) throws Exception{
    		String rec =null;
    		while (flag) {
    			   Thread.sleep(10);
    			   rec = WebRecorder.recData;
    				if(rec !=null){
    					synchronized(rec) {
    					ByteBuffer byteBuf = ByteBuffer.allocate(30);
    					byteBuf.put(rec.getBytes("UTF-8"));
    					handle.responseClient(byteBuf, true);
    					System.out.println("返回成功"+rec);
    					WebRecorder.recData=null;
    				}
    			}	
    		}
    	}
    }