简单服务器开发（八）响应动态：客户端访问小Java程序

package org.zda.oa.servlet;
/**
 * 处理登录业务的java程序，该java程序由webApp开发人，由web服务器开人员负责调用
 * @author webApp开发人员
 * @version    1.0
 * @since    1.0
 *
 */
public class LoginServlet {
    //处理业务的核心类
    public void service(){
        System.out.println("正在验证身份，请稍等....");
    }
}

package com.zda.httpserver.core;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

import org.zda.oa.servlet.LoginServlet;

import com.zda.httpserver.util.Logger;

/**
 * 处理客户端请求
 * @author zda
 * @version 1.0
 * @since    1.0
 */
public class HandlerRequest implements Runnable {
    public Socket clientSocket;
    public HandlerRequest(Socket clientSocket){
        this.clientSocket = clientSocket;
    }

    @Override
    public void run() {
        //处理客户端请求
        BufferedReader br = null;
        PrintWriter out = null;
        Logger.log("httpserver thread: " + Thread.currentThread().getName());
        try {
            //接收客户端消息
            br = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
            //获取响应流对象
            out = new PrintWriter(clientSocket.getOutputStream());
            //获取请求协议的请求行
            String requestLine = br.readLine();// GET /oa/index.html HTTP/1.1
            //获取URI -> 请求行（requestLine） -> 请求方式  URI 请求协议版本号 -> 三者之间是通过一个空格进行连接
            String requestURI = requestLine.split(" ")[1];//{"GET","/oa/index.html","HTTP/1.1"}
            System.out.println(requestURI);
            //判断用户请求是否为一个静态页面：以.html或.htm结尾的文件叫作html页面
            if(requestURI.endsWith(".html") || requestURI.endsWith(".htm")){
                //处理静态页面的方法
                responseStaticPage(requestURI,out);
            }else{//动态资源：java程序，业务处理类
                //requestURI: /oa/login?username=zhangsan&password=111
                //requestURI: /oa/login
                
                String servletPath = requestURI;
                //判断servletPath是否包含参数
                if(servletPath.contains("?")){
                    //split后面是正则表达式，？在正则表达式中有特殊含义，需要转义
                    servletPath = servletPath.split("[?]")[0];// /oa/login
                }
                    
                if("/oa/login".equals(servletPath)){
                    LoginServlet loginServlet = new LoginServlet();
                    loginServlet.service();
                }
            }
            //强制刷新
            out.flush();            
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            //关闭资源
            if(br != null){
                try {
                    br.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(clientSocket != null){
                try {
                    clientSocket.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
        
    }

    /**
     * 处理静态页面
     * @param requestURI 请求URI
     * @param out    响应流对象
     */
    public void responseStaticPage(String requestURI, PrintWriter out) {
        //requestURI:/oa/index.html
        //静态页面的路径：oa/index.html
        String htmlPath = requestURI.substring(1);
        BufferedReader br = null;
        try {
            //读取页面
            br = new BufferedReader(new FileReader(htmlPath));
            StringBuilder html = new StringBuilder();
            //拼接响应信息
            html.append("HTTP/1.1 200 OK\n");
            html.append("Content-Type:text/html;charset=utf-8\n\n");
            String temp = null;
            while((temp = br.readLine()) != null){
                html.append(temp);
            }
            //输出html
            out.print(html);
        } catch (FileNotFoundException e) {
            //404找不到资源
            StringBuilder html = new StringBuilder();
            html.append("HTTP/1.1 404 NotFound\n");
            html.append("Content-Type:text/html;charset=utf-8\n\n");
            html.append("<html>");
            html.append("<head>");
            html.append("<title>404-错误</title>");
            html.append("<meta content=‘text/html;charset=utf-8‘/>");
            html.append("</head>");
            html.append("<body>");
            html.append("<center><font size=‘35px‘ color=‘red‘>404-Not Found</font></center>");
            html.append("</body>");
            html.append("</html>");
            out.print(html);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}