Java Socket 实现HTTP服务器核心

原文地址：http://www.ihuxu.com/p/235.html

 

首先了解下HTTP协议：

wikiPedia的说明很好，在此不重复了。链接：http://zh.wikipedia.org/wiki/Http

 

源码分析：

概述：此两个代码段，完成服务器监听，线程处理短请求服务和应答（符合伪HTTP协议，“伪”即判断协议格式不严谨）。展示了利用java socket完成http通信的核心原理代码，希望给初次学习socket或者第一次利用java来实现HTTP协议服务器的朋友提供些帮助。

 

利用 Java Socket 网络编程来绑定服务器某个端口进行监听。

 

package JHServer;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

    private static int PORT = 1720;
    public static String charset = "utf-8";
    private ServerSocket ss;
    private Socket client;

    public static void main(String[] args) {
        new Server();
    }

    public Server() {
        try {
            this.ss = new ServerSocket(this.PORT);
System.out.println("Server Listening Port " + this.PORT + "...");
            boolean isGo = true;
            while(isGo){
                this.client = this.ss.accept();
System.out.println("One Client Connected. " + this.client);
                ClientThread ct = new ClientThread(this.client);
                Thread t = new Thread(ct);
                t.start();
System.out.println("One Client Thread Already Started...");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try{
                if(this.ss != null){
                    this.ss.close();
                    this.ss = null;
                }
                if(this.client != null){
                    this.client.close();
                    this.client = null;
                }
            } catch(IOException e) {
                e.printStackTrace();
            }
        }
    }

}

说明：上述代码完成了服务端口（1720，你懂么）的监听，并同时利用线程了处理每个客户端（Client ）的消息请求，以减少服务器处理”短请求“阻塞问题。

 

 

下述代码完成请求是否符合伪HTTP协议，并完成响应消息。

 

package JHServer;

import java.io.*;
import java.net.Socket;
import java.util.Date;

import action.ManagerEachMatchInfo;

import view.*;

public class ClientThread implements Runnable {

    private float requestDelay = (float)0.5;//

    private Socket _s;
    private BufferedReader i;
    private PrintStream o;

    public ClientThread(Socket s) {
        this._s = s;
    }

    public void run() {
        try {
            this.i = new BufferedReader(new InputStreamReader(this._s.getInputStream()));
            this.o = new PrintStream(this._s.getOutputStream());

            String request = this.getValidRequest();

            if( !request.equals("") ) {
                System.out.print("当前虚拟机最大可用内存为:");
                System.out.println(Runtime.getRuntime().maxMemory()/1024/1024+"M");
                System.out.print("当前，虚拟机已占用内存:");
                System.out.println(Runtime.getRuntime().totalMemory()/1024/1024+"M");
                this.o.println("HTTP/1.1 200 OK");
                Date now = new Date();
                this.o.println("Data:" + now);
                this.o.println("Server: JHServer");
                this.o.println("Access-Control-Allow-Origin:*");

                this.o.println("Content-Type: text/html; charset=UTF-8");
                this.o.println();
                String content = null;
                IndeMatchInfo imi = new IndeMatchInfo(22,22,2,2,22,(double)0.0,"S7-200");
                content = imi.getHTML();

                imi.clear();
                imi = null;
                System.out.print("当前虚拟机最大可用内存为:");
                System.out.println(Runtime.getRuntime().maxMemory()/1024/1024+"M");
                System.out.print("当前，虚拟机已占用内存:");
                System.out.println(Runtime.getRuntime().totalMemory()/1024/1024+"M");

                this.o.println(content);
                content = "";
                this.o.flush();

            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            this.close();
        }

    }

    private String getValidRequest() {

        float second = (float) 0.0;
        boolean isGo = true;
        String request = null;
        try {
            while (!this.i.ready()) {
                second += 0.01;
                if (second > this.requestDelay) {
                    System.out.println("One Client Delayed " + this._s);
                    isGo = false;
                    break;
                }
                Thread.sleep(10);
            }

            if (isGo == true) {
                request = this.i.readLine();
                if( request.contains("GET /") && request.contains(" HTTP/") ) {
                    request = request.substring(request.indexOf("/"),request.indexOf(" HTTP/"));
System.out.println("Client Request Info: " + request);
                } else {
                    isGo = false;
                }
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(isGo == true) {
                return request;
            } else {
                return "null";
            }
        }
    }

    private void close() {
        try {
            if (this.i != null) {
                this.i.close();
                this.i = null;
            }
            if (this.o != null) {
                this.o.close();
                this.o = null;
            }
            if (this._s != null) {
                this._s.close();
                this._s = null;
            }
System.out.println("One Client Disconnected...");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

说明：

 

1、getValidRequest() 验证请求消息是否满足伪HTTP协议。比如：GET /images/logo.gif HTTP/1.1，则会返回"/images/logo.gif"。若不符合伪HTTP协议或者请求时不发送任何消息头（比如通过telnet访问，此情况最大延迟0.5秒），则会返回空串。

2、close()，释放内存，同时线程结束。

3、run()，短请求的线程主体，在此处可以进行数据逻辑处理，并返回特定消息内容。