JAVA Sokcet(服务端)连接WebSocket个人总结

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;
}
}
}
}
}