jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/util/CloseableURLClassLoader.java@7c537f4298fb (annotated)

src/share/classes/com/sun/tools/javac/util/CloseableURLClassLoader.java@7c537f4298fb (annotated)

src/share/classes/com/sun/tools/javac/util/CloseableURLClassLoader.java

Mon, 10 Jan 2011 15:08:31 -0800

author: jjg
date: Mon, 10 Jan 2011 15:08:31 -0800
changeset 816: 7c537f4298fb
parent 581: f2fdd52e4e87
permissions: -rw-r--r--

6396503: javac should not require assertions enabled
Reviewed-by: mcimadamore

 /*
  * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package com.sun.tools.javac.util;
 import java.io.Closeable;
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.jar.JarFile;
 /**
  * A URLClassLoader that also implements Closeable.
  * Reflection is used to access internal data structures in the URLClassLoader,
  * since no public API exists for this purpose. Therefore this code is somewhat
  * fragile. Caveat emptor.
  * @throws Error if the internal data structures are not as expected.
  *
  *  <p><b>This is NOT part of any supported API.
  *  If you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 public class CloseableURLClassLoader
         extends URLClassLoader implements Closeable {
     public CloseableURLClassLoader(URL[] urls, ClassLoader parent) throws Error {
         super(urls, parent);
         try {
             getLoaders(); //proactive check that URLClassLoader is as expected
         } catch (Throwable t) {
             throw new Error("cannot create CloseableURLClassLoader", t);
         }
     }
     /**
      * Close any jar files that may have been opened by the class loader.
      * Reflection is used to access the jar files in the URLClassLoader's
      * internal data structures.
      * @throws java.io.IOException if the jar files cannot be found for any
      * reson, or if closing the jar file itself causes an IOException.
      */
     @Override
     public void close() throws IOException {
         try {
             for (Object l: getLoaders()) {
                 if (l.getClass().getName().equals("sun.misc.URLClassPath$JarLoader")) {
                     Field jarField = l.getClass().getDeclaredField("jar");
                     JarFile jar = (JarFile) getField(l, jarField);
                     if (jar != null) {
                         //System.err.println("CloseableURLClassLoader: closing " + jar);
                         jar.close();
                     }
                 }
             }
         } catch (Throwable t) {
             IOException e = new IOException("cannot close class loader");
             e.initCause(t);
             throw e;
         }
     }
     private ArrayList<?> getLoaders()
             throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException
     {
         Field ucpField = URLClassLoader.class.getDeclaredField("ucp");
         Object urlClassPath = getField(this, ucpField);
         if (urlClassPath == null)
             throw new AssertionError("urlClassPath not set in URLClassLoader");
         Field loadersField = urlClassPath.getClass().getDeclaredField("loaders");
         return (ArrayList<?>) getField(urlClassPath, loadersField);
     }
     private Object getField(Object o, Field f)
             throws IllegalArgumentException, IllegalAccessException {
         boolean prev = f.isAccessible();
         try {
             f.setAccessible(true);
             return f.get(o);
         } finally {
             f.setAccessible(prev);
         }
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/util/CloseableURLClassLoader.java@7c537f4298fb (annotated)

src/share/classes/com/sun/tools/javac/util/CloseableURLClassLoader.java