javassist.tools.web.Webserver Maven / Gradle / Ivy
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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.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.NotFoundException;
import javassist.Translator;
/**
* 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;
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;
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;
}
@Override
public void run() {
try {
web.process(sock);
}
catch (IOException e) {
}
}
}