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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;

import java.io.*;
import java.net.*;

/**
 * A class search-path specified with URL (http).
 *
 * @see javassist.ClassPath
 * @see ClassPool#insertClassPath(ClassPath)
 * @see ClassPool#appendClassPath(ClassPath)
 */
public class URLClassPath implements ClassPath {
    protected String hostname;
    protected int port;
    protected String directory;
    protected String packageName;

    /**
     * Creates a search path specified with URL (http).
     *
     * 

This search path is used only if a requested * class name starts with the name specified by packageName. * If packageName is "org.javassist." and a requested class is * "org.javassist.test.Main", then the given URL is used for loading that class. * The URLClassPath obtains a class file from: * *

    http://www.javassist.org:80/java/classes/org/javassist/test/Main.class
         * 
* *

Here, we assume that host is "www.javassist.org", * port is 80, and directory is "/java/classes/". * *

If packageName is null, the URL is used * for loading any class. * * @param host host name * @param port port number * @param directory directory name ending with "/". * It can be "/" (root directory). * It must start with "/". * @param packageName package name. It must end with "." (dot). */ public URLClassPath(String host, int port, String directory, String packageName) { hostname = host; this.port = port; this.directory = directory; this.packageName = packageName; } public String toString() { return hostname + ":" + port + directory; } /** * Opens a class file with http. * * @return null if the class file could not be found. */ public InputStream openClassfile(String classname) { try { URLConnection con = openClassfile0(classname); if (con != null) return con.getInputStream(); } catch (IOException e) {} return null; // not found } private URLConnection openClassfile0(String classname) throws IOException { if (packageName == null || classname.startsWith(packageName)) { String jarname = directory + classname.replace('.', '/') + ".class"; return fetchClass0(hostname, port, jarname); } else return null; // not found } /** * Returns the URL. * * @return null if the class file could not be obtained. */ public URL find(String classname) { try { URLConnection con = openClassfile0(classname); InputStream is = con.getInputStream(); if (is != null) { is.close(); return con.getURL(); } } catch (IOException e) {} return null; } /** * Closes this class path. */ public void close() {} /** * Reads a class file on an http server. * * @param host host name * @param port port number * @param directory directory name ending with "/". * It can be "/" (root directory). * It must start with "/". * @param classname fully-qualified class name */ public static byte[] fetchClass(String host, int port, String directory, String classname) throws IOException { byte[] b; URLConnection con = fetchClass0(host, port, directory + classname.replace('.', '/') + ".class"); int size = con.getContentLength(); InputStream s = con.getInputStream(); try { if (size <= 0) b = ClassPoolTail.readStream(s); else { b = new byte[size]; int len = 0; do { int n = s.read(b, len, size - len); if (n < 0) throw new IOException("the stream was closed: " + classname); len += n; } while (len < size); } } finally { s.close(); } return b; } private static URLConnection fetchClass0(String host, int port, String filename) throws IOException { URL url; try { url = new URL("http", host, port, filename); } catch (MalformedURLException e) { // should never reache here. throw new IOException("invalid URL?"); } URLConnection con = url.openConnection(); con.connect(); return con; } }





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