java使用socket实现一个多线程web服务器的方法

package com.lp.app.webserver;import java.io.*;import java.net.*;//使用Socket创建一个WEB服务器，本程序是多线程系统以提高反应速度。class WebServer{ public static String WEBROOT = "";//默认目录 public static String defaultPage = "index.htm";//默认文件 public static void main (String [] args) throws IOException { System.out.println ("服务器启动.../n");  //使用8080端口提供服务 ServerSocket server = new ServerSocket (8080); while (true) {  //阻塞，直到有客户连接  Socket sk = server.accept ();  System.out.println ("Accepting Connection.../n");  //启动服务线程  new WebThread (sk).start (); } }}//使用线程，为多个客户端服务class WebThread extends Thread{ private Socket sk; WebThread (Socket sk) {  this.sk = sk; } //线程体 public void run () {  InputStream in = null;  OutputStream out = null;  try{  in = sk.getInputStream();  out = sk.getOutputStream();  //接收来自客户端的请求。  Request rq = new Request(in);  //解析客户请求  String sURL = rq.parse();  System.out.println("sURL="+sURL);  if(sURL.equals("/"))    sURL = WebServer.defaultPage;  Response rp = new Response(out);  rp.Send(sURL);   }  catch (IOException e)  {  System.out.println (e.toString ());  }  finally  {  System.out.println ("关闭连接.../n");  //最后释放资源  try{   if (in != null)   in.close ();   if (out != null)   out.close ();   if (sk != null)   sk.close ();  }  catch (IOException e)  {  }  } }}

package com.lp.app.webserver;import java.io.*;import java.net.*;//获取客户的HTTP请求，分析客户所需要的文件public class Request{ InputStream in = null; //获得输入流。这是客户的请求数据。 public Request(InputStream input){ this.in = input; } //解析客户的请求 public String parse() { //从Socket读取一组数据 StringBuffer requestStr = new StringBuffer(2048); int i; byte[] buffer = new byte[2048]; try { i = in.read(buffer); } catch (IOException e) { e.printStackTrace(); i = -1; } for (int j=0; j<i; j++) { requestStr.append((char) buffer[j]); } System.out.print(requestStr.toString()); return getUri(requestStr.toString()); } //获取URI信息字符 private String getUri(String requestString) { int index1, index2; index1 = requestString.indexOf(' '); if (index1 != -1) { index2 = requestString.indexOf(' ', index1 + 1); if (index2 > index1)  return requestString.substring(index1 + 1, index2); } return null; }}

package com.lp.app.webserver;import java.io.*;import java.net.*;//获得用户请求后将用户需要的文件读出，添加上HTTP应答头。发送给客户端。public class Response{ OutputStream out = null; //发送请求的文件 public void Send(String ref) throws IOException { byte[] bytes = new byte[2048]; FileInputStream fis = null; try { //构造文件 File file = new File(WebServer.WEBROOT, ref); if (file.exists()) {  //构造输入文件流  fis = new FileInputStream(file);  int ch = fis.read(bytes, 0, 2048);  //读取文件  String sBody = new String(bytes,0);  //构造输出信息  String sendMessage = "HTTP/1.1 200 OK/r/n" +  "Content-Type: text/html/r/n" +  "Content-Length: "+ch+"/r/n" +  "/r/n" +sBody;  //输出文件  out.write(sendMessage.getBytes()); }else {  // 找不到文件  String errorMessage = "HTTP/1.1 404 File Not Found/r/n" +  "Content-Type: text/html/r/n" +  "Content-Length: 23/r/n" +  "/r/n" +  "<h1>File Not Found</h1>";  out.write(errorMessage.getBytes()); } } catch (Exception e) { // 如不能实例化File对象，抛出异常。 System.out.println(e.toString() ); } finally { if (fis != null)  fis.close(); } } //获取输出流 public Response(OutputStream output) { this.out = output;}}