simpleproxy.java

JAVA案例开发集锦源代码 袁然 郑自国编

/*
 * 代理服务器
 */
import java.net.*;
import java.io.*;
import java.util.*;
import java.text.*;
import java.text.DateFormat.*;
import java.lang.reflect.*;

public class SimpleProxy extends Thread {
    static public int Retry_Num=3;
    static public int Connect_Delay=3;
    static public int TimeOut=20;
    static public int BufferSize=1024;
    static public boolean Passport = false;
    static public OutputStream Message=null;

    // 传入数据用Socket
    protected Socket socket;
    // 上级代理服务器
    static private String Parent=null;
    static private int ParentPort=-100;

static public void ParentProxy(String parentname, int portnum) {
        Parent=parentname;
        ParentPort=portnum;
    }
    // 在给定Socket上创建一个代理线程。
    public SimpleProxy(Socket sock) {
         socket=sock;
         start();
   }

    public void recordLog(int c) throws IOException {
        Message.write(c);
    }
  //记录、输出日志
    public void recordLog(byte[] bytes,int c, int lenth) throws IOException {
        for (int i=0;i<lenth;i++)
        recordLog((int)bytes[c+i]);
    }
    // 默认情况下，日志信息输出到标准输出设备

    public String getHostName(String url, String host, int portnum, Socket sock) {
        DateFormat ware=DateFormat.getDateTimeInstance();
        System.out.println(ware.format(new Date()) + " - " + url + " "
              + sock.getInetAddress()+"\n");
        return host;
    }

    // 执行操作的线程
    public void run() {
        String strline;
        String strhost;
        int port=80;
        Socket out=null;
        try {
            socket.setSoTimeout(TimeOut);
            InputStream instr=socket.getInputStream();
            OutputStream osstr=null;
            try {
                // 获取请求行的内容
                strline="";
                strhost="";
                int state=0;
                boolean blank;
                while (true) {
                    int l=instr.read();
                    if (l==-1) break;
                    if (Passport) recordLog(l);
                    blank=Character.isWhitespace((char)l);
                    switch (state) {
                    case 0:
                        if (blank) continue;
                        state=1;
                    case 1:
                        if (blank) {
                            state=2;
                            continue;
                        }
                        strline=strline+(char)l;
                        break;
                    case 2:
                        if (blank) continue;
                        // 跳过空白字符
                        state=3;
                    case 3:
                        if (blank) {
                            state=4;
                            // 只取出主机名称部分
                            String host=strhost;
                            int n;
                            n=strhost.indexOf("//");
                            if (n!=-1) strhost=strhost.substring(n+2);
                            n=strhost.indexOf('/');
                            if (n!=-1) strhost=strhost.substring(0,n);
                            // 分析可能存在的端口号
                            n=strhost.indexOf(":");
                            if (n!=-1) {
                                port=Integer.parseInt(strhost.substring(n+1));
                                strhost=strhost.substring(0,n);
                            }
                            strhost=getHostName(host,strhost,port,socket);
                            if (Parent!=null) {
                                strhost=Parent;
                                port=ParentPort;
                                //处理上级代理
                            }
                            int retry=Retry_Num;
                            while (retry--!=0) {
                                try {
                                    out=new Socket(strhost,port);
                                    break;
                                } catch (Exception e) { }
                                // 等待
                                Thread.sleep(Connect_Delay);
                            }
                            if (out==null) break;
                            out.setSoTimeout(TimeOut);
                            osstr=out.getOutputStream();
                            osstr.write(strline.getBytes());
                            osstr.write(' ');
                            osstr.write(host.getBytes());
                            osstr.write(' ');
                            check(instr,out.getInputStream(),osstr,socket.getOutputStream());
                            break;
                        }
                        strhost=strhost+(char)l;
                        break;
                    }
                }
            }
            catch (IOException e) {
            }
    } catch (Exception e) {
    }
    finally {
                    try {
                        socket.close();
                        } catch (Exception e1) {
                        }
                        //关闭socket
                    try {
                        out.close();
                        } catch (Exception e2) {
                        }
                        //关闭socket
       }
    }


    void check(InputStream instr0, InputStream instr1,
         OutputStream outstr0,  OutputStream outstr1) throws IOException {
        try {
            int len;
            byte bytes[]=new byte[BufferSize];
            while (true) {
                try {
                    if ((len=instr0.read(bytes))>0) {
                        outstr0.write(bytes,0,len);
                        if (Passport)
                            recordLog(bytes,0,len);
                    }
                    else if (len<0)
                        break;
                } catch (InterruptedIOException e) {
                }
                try {
                    if ((len=instr1.read(bytes))>0) {
                        outstr1.write(bytes,0,len);
                        if (Passport)
                            recordLog(bytes,0,len);
                    }
                    else if (len<0)
                        break;
                } catch (InterruptedIOException e) {
                }
            }
        } catch (Exception e0) {
            System.out.println("异常: " + e0);
        }
    }

    static public void startProxy(int port,Class test) {
        ServerSocket sersock;
        Socket sock;
        try {
            sersock=new ServerSocket(port);
            while (true) {
                Class [] sarg = new Class[1];
                Object [] arg= new Object[1];
                sarg[0]=Socket.class;
                try {
                    Constructor layer = test.getDeclaredConstructor(sarg);
                    arg[0]=sersock.accept();
                    layer.newInstance(arg);
                // 创建SimpleProxy及其派生类的实例
                } catch (Exception e) {
                    Socket esock = (Socket)arg[0];
                    try { esock.close();
                        } catch (Exception ec) {}
                }
            }
        } catch (IOException e) {
        }
    }


    // main方法,用于简单测试
    static public void main(String args[]) {
        System.out.println("在端口808启动代理服务器\n");
        SimpleProxy.Message=System.out;
        SimpleProxy.Passport=false;
        SimpleProxy.startProxy(808,SimpleProxy.class);
      }
    }