Java学习:一个基础的代理服务器类
/************************************** 一个基础的代理服务器类
*************************************
*/
import java.net.*;import java.io.*;public class HttpProxy extends Thread { static public int CONNECT_RETRIES=5; static public int CONNECT_PAUSE=5; static public int TIMEOUT=50; static public int BUFSIZ=1024; static public boolean logging = false; static public OutputStream log=null; // 传入数据用的Socket protected Socket socket; // 上级代理服务器，可选 static private String parent=null; static private int parentPort=-1; static public void setParentProxy(String name, int pport) { parent=name; parentPort=pport; } // 在给定Socket上创建一个代理线程。 public HttpProxy(Socket s) { socket=s; start(); } public void writeLog(int c, boolean browser) throws IOException { log.write(c); } public void writeLog(byte[] bytes,int offset, int len, boolean browser) throws IOException { for (int i=0;i<len;i++) writeLog((int)bytes,browser); } // 默认情况下，日志信息输出到 // 标准输出设备 // 派生类可以覆盖它 public String processHostName(String url, String host, int port, Socket sock) {java.text.DateFormat cal=java.text.DateFormat.getDateTimeInstance();System.out.println(cal.format(new java.util.Date()) + " - " + url + " " + sock.getInetAddress()+"\n"); return host; } // 执行操作的线程public void run() {String line;String host;int port=80; Socket outbound=null; try { socket.setSoTimeout(TIMEOUT); InputStream is=socket.getInputStream(); OutputStream os=null; try { // 获取请求行的内容 line=""; host=""; int state=0; boolean space; while (true) { int c=is.read(); if (c==-1) break; if (logging) writeLog(c,true); space=Character.isWhitespace((char)c); switch (state) { case 0: if (space) continue; state=1; case 1: if (space) { state=2; continue; } line=line+(char)c; break; case 2: if (space) continue; // 跳过多个空白字符 state=3; case 3: if (space) { state=4; // 只取出主机名称部分 String host0=host; int n; n=host.indexOf("//"); if (n!=-1) host=host.substring(n+2); n=host.indexOf('/'); if (n!=-1) host=host.substring(0,n); // 分析可能存在的端口号 n=host.indexOf(":"); if (n!=-1) { port=Integer.parseInt(host.substring(n+1)); host=host.substring(0,n); } host=processHostName(host0,host,port,socket); if (parent!=null) { host=parent; port=parentPort; } int retry=CONNECT_RETRIES; while (retry--!=0) { try { outbound=new Socket(host,port); break; } catch (Exception e) { } // 等待 Thread.sleep(CONNECT_PAUSE); } if (outbound==null) break; outbound.setSoTimeout(TIMEOUT); os=outbound.getOutputStream(); os.write(line.getBytes()); os.write(' '); os.write(host0.getBytes()); os.write(' '); pipe(is,outbound.getInputStream(),os,socket.getOutputStream()); break; } host=host+(char)c; break; } } } catch (IOException e) { } } catch (Exception e) { } finally { try { socket.close();} catch (Exception e1) {} try { outbound.close();} catch (Exception e2) {} } } void pipe(InputStream is0, InputStream is1, OutputStream os0,OutputStream os1) throws IOException { try { int ir; byte bytes[]=new byte;while (true) { try { if ((ir=is0.read(bytes))>0) { os0.write(bytes,0,ir); if (logging) writeLog(bytes,0,ir,true); } else if (ir<0) break; } catch (InterruptedIOException e) { } try { if ((ir=is1.read(bytes))>0) { os1.write(bytes,0,ir); if (logging) writeLog(bytes,0,ir,false); } else if (ir<0) break; } catch (InterruptedIOException e) { } } } catch (Exception e0) { System.out.println("Pipe异常: " + e0); } } static public void startProxy(int port,Class clobj) { ServerSocket ssock; Socket sock; try { ssock=new ServerSocket(port); while (true) { Class [] sarg = new Class; Object [] arg= new Object; sarg=Socket.class; try { java.lang.reflect.Constructor cons = clobj.getDeclaredConstructor(sarg); arg=ssock.accept(); cons.newInstance(arg); // 创建HttpProxy或其派生类的实例 } catch (Exception e) { Socket esock = (Socket)arg; try { esock.close(); } catch (Exception ec) {} } } } catch (IOException e) { } } // 测试用的简单main方法 static public void main(String args[]) { System.out.println("在端口8080启动代理服务器\n"); HttpProxy.log=System.out; HttpProxy.logging=false; HttpProxy.startProxy(8080,HttpProxy.class); } }
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