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/*
 * Javassist, a Java-bytecode translator toolkit.
 * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License.  Alternatively, the contents of this file may be used under
 * the terms of the GNU Lesser General Public License Version 2.1 or later,
 * or the Apache License Version 2.0.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 */

package javassist.tools.web;

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

/**
 * A web server for running sample programs.
 *
 * 

This enables a Java program to instrument class files loaded by * web browsers for applets. Since the (standard) security manager * does not allow an applet to create and use a class loader, * instrumenting class files must be done by this web server. * *

Note: although this class is included in the Javassist API, * it is provided as a sample implementation of the web server using * Javassist. Especially, there might be security flaws in this server. * Please use this with YOUR OWN RISK. */ public class Webserver { private ServerSocket socket; private ClassPool classPool; protected Translator translator; private final static byte[] endofline = { 0x0d, 0x0a }; private final static int typeHtml = 1; private final static int typeClass = 2; private final static int typeGif = 3; private final static int typeJpeg = 4; private final static int typeText = 5; /** * If this field is not null, the class files taken from * ClassPool are written out under the directory * specified by this field. The directory name must not end * with a directory separator. */ public String debugDir = null; /** * The top directory of html (and .gif, .class, ...) files. * It must end with the directory separator such as "/". * (For portability, "/" should be used as the directory separator. * Javassist automatically translates "/" into a platform-dependent * character.) * If this field is null, the top directory is the current one where * the JVM is running. * *

If the given URL indicates a class file and the class file * is not found under the directory specified by this variable, * then Class.getResourceAsStream() is called * for searching the Java class paths. */ public String htmlfileBase = null; /** * Starts a web server. * The port number is specified by the first argument. */ public static void main(String[] args) throws IOException { if (args.length == 1) { Webserver web = new Webserver(args[0]); web.run(); } else System.err.println( "Usage: java javassist.tools.web.Webserver "); } /** * Constructs a web server. * * @param port port number */ public Webserver(String port) throws IOException { this(Integer.parseInt(port)); } /** * Constructs a web server. * * @param port port number */ public Webserver(int port) throws IOException { socket = new ServerSocket(port); classPool = null; translator = null; } /** * Requests the web server to use the specified * ClassPool object for obtaining a class file. */ public void setClassPool(ClassPool loader) { classPool = loader; } /** * Adds a translator, which is called whenever a client requests * a class file. * * @param cp the ClassPool object for obtaining * a class file. * @param t a translator. */ public void addTranslator(ClassPool cp, Translator t) throws NotFoundException, CannotCompileException { classPool = cp; translator = t; t.start(classPool); } /** * Closes the socket. */ public void end() throws IOException { socket.close(); } /** * Prints a log message. */ public void logging(String msg) { System.out.println(msg); } /** * Prints a log message. */ public void logging(String msg1, String msg2) { System.out.print(msg1); System.out.print(" "); System.out.println(msg2); } /** * Prints a log message. */ public void logging(String msg1, String msg2, String msg3) { System.out.print(msg1); System.out.print(" "); System.out.print(msg2); System.out.print(" "); System.out.println(msg3); } /** * Prints a log message with indentation. */ public void logging2(String msg) { System.out.print(" "); System.out.println(msg); } /** * Begins the HTTP service. */ public void run() { System.err.println("ready to service..."); for (;;) try { ServiceThread th = new ServiceThread(this, socket.accept()); th.start(); } catch (IOException e) { logging(e.toString()); } } final void process(Socket clnt) throws IOException { InputStream in = new BufferedInputStream(clnt.getInputStream()); String cmd = readLine(in); logging(clnt.getInetAddress().getHostName(), new Date().toString(), cmd); while (skipLine(in) > 0){ } OutputStream out = new BufferedOutputStream(clnt.getOutputStream()); try { doReply(in, out, cmd); } catch (BadHttpRequest e) { replyError(out, e); } out.flush(); in.close(); out.close(); clnt.close(); } private String readLine(InputStream in) throws IOException { StringBuffer buf = new StringBuffer(); int c; while ((c = in.read()) >= 0 && c != 0x0d) buf.append((char)c); in.read(); /* skip 0x0a (LF) */ return buf.toString(); } private int skipLine(InputStream in) throws IOException { int c; int len = 0; while ((c = in.read()) >= 0 && c != 0x0d) ++len; in.read(); /* skip 0x0a (LF) */ return len; } /** * Proceses a HTTP request from a client. * * @param out the output stream to a client * @param cmd the command received from a client */ public void doReply(InputStream in, OutputStream out, String cmd) throws IOException, BadHttpRequest { int len; int fileType; String filename, urlName; if (cmd.startsWith("GET /")) filename = urlName = cmd.substring(5, cmd.indexOf(' ', 5)); else throw new BadHttpRequest(); if (filename.endsWith(".class")) fileType = typeClass; else if (filename.endsWith(".html") || filename.endsWith(".htm")) fileType = typeHtml; else if (filename.endsWith(".gif")) fileType = typeGif; else if (filename.endsWith(".jpg")) fileType = typeJpeg; else fileType = typeText; // or textUnknown len = filename.length(); if (fileType == typeClass && letUsersSendClassfile(out, filename, len)) return; checkFilename(filename, len); if (htmlfileBase != null) filename = htmlfileBase + filename; if (File.separatorChar != '/') filename = filename.replace('/', File.separatorChar); File file = new File(filename); if (file.canRead()) { sendHeader(out, file.length(), fileType); FileInputStream fin = new FileInputStream(file); byte[] filebuffer = new byte[4096]; for (;;) { len = fin.read(filebuffer); if (len <= 0) break; else out.write(filebuffer, 0, len); } fin.close(); return; } // If the file is not found under the html-file directory, // then Class.getResourceAsStream() is tried. if (fileType == typeClass) { InputStream fin = getClass().getResourceAsStream("/" + urlName); if (fin != null) { ByteArrayOutputStream barray = new ByteArrayOutputStream(); byte[] filebuffer = new byte[4096]; for (;;) { len = fin.read(filebuffer); if (len <= 0) break; else barray.write(filebuffer, 0, len); } byte[] classfile = barray.toByteArray(); sendHeader(out, classfile.length, typeClass); out.write(classfile); fin.close(); return; } } throw new BadHttpRequest(); } private void checkFilename(String filename, int len) throws BadHttpRequest { for (int i = 0; i < len; ++i) { char c = filename.charAt(i); if (!Character.isJavaIdentifierPart(c) && c != '.' && c != '/') throw new BadHttpRequest(); } if (filename.indexOf("..") >= 0) throw new BadHttpRequest(); } private boolean letUsersSendClassfile(OutputStream out, String filename, int length) throws IOException, BadHttpRequest { if (classPool == null) return false; byte[] classfile; String classname = filename.substring(0, length - 6).replace('/', '.'); try { if (translator != null) translator.onLoad(classPool, classname); CtClass c = classPool.get(classname); classfile = c.toBytecode(); if (debugDir != null) c.writeFile(debugDir); } catch (Exception e) { throw new BadHttpRequest(e); } sendHeader(out, classfile.length, typeClass); out.write(classfile); return true; } private void sendHeader(OutputStream out, long dataLength, int filetype) throws IOException { out.write("HTTP/1.0 200 OK".getBytes()); out.write(endofline); out.write("Content-Length: ".getBytes()); out.write(Long.toString(dataLength).getBytes()); out.write(endofline); if (filetype == typeClass) out.write("Content-Type: application/octet-stream".getBytes()); else if (filetype == typeHtml) out.write("Content-Type: text/html".getBytes()); else if (filetype == typeGif) out.write("Content-Type: image/gif".getBytes()); else if (filetype == typeJpeg) out.write("Content-Type: image/jpg".getBytes()); else if (filetype == typeText) out.write("Content-Type: text/plain".getBytes()); out.write(endofline); out.write(endofline); } private void replyError(OutputStream out, BadHttpRequest e) throws IOException { logging2("bad request: " + e.toString()); out.write("HTTP/1.0 400 Bad Request".getBytes()); out.write(endofline); out.write(endofline); out.write("

Bad Request

".getBytes()); } } class ServiceThread extends Thread { Webserver web; Socket sock; public ServiceThread(Webserver w, Socket s) { web = w; sock = s; } public void run() { try { web.process(sock); } catch (IOException e) { } } }




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