123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140 |
- /*
- * 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.InputStream;
- import java.net.URL;
- import java.lang.ref.WeakReference;
-
- /**
- * A class search-path representing a class loader.
- *
- * <p>It is used for obtaining a class file from the given
- * class loader by <code>getResourceAsStream()</code>.
- * The <code>LoaderClassPath</code> refers to the class loader through
- * <code>WeakReference</code>. If the class loader is garbage collected,
- * the other search pathes are examined.
- *
- * <p>The given class loader must have both <code>getResourceAsStream()</code>
- * and <code>getResource()</code>.
- *
- * <p>Class files in a named module are private to that module.
- * This method cannot obtain class files in named modules.
- * </p>
- *
- * @author <a href="mailto:bill@jboss.org">Bill Burke</a>
- * @author Shigeru Chiba
- *
- * @see ClassPool#insertClassPath(ClassPath)
- * @see ClassPool#appendClassPath(ClassPath)
- * @see ClassClassPath
- * @see ModuleClassPath
- */
- public class LoaderClassPath implements ClassPath {
- private WeakReference clref;
-
- /**
- * If true, this search path implicitly includes
- * a {@code ModuleClassPath} as a fallback.
- * For backward compatibility, this field is set to true
- * if the JVM is Java 9 or later. It can be false in
- * Java 9 but the behavior of {@code LoadClassPath} will
- * be different from its behavior in Java 8 or older.
- *
- * <p>This field must be false if the JVM is Java 8 or older.
- *
- * @since 3.21
- */
- public static boolean fallbackOnModuleClassPath
- = javassist.bytecode.ClassFile.MAJOR_VERSION >= javassist.bytecode.ClassFile.JAVA_9;
-
- private static ModuleClassPath moduleClassPath = null;
-
- private boolean doFallback;
-
- /**
- * Creates a search path representing a class loader.
- */
- public LoaderClassPath(ClassLoader cl) {
- this(cl, fallbackOnModuleClassPath);
- }
-
- LoaderClassPath(ClassLoader cl, boolean fallback) {
- clref = new WeakReference(cl);
- doFallback = fallback;
- if (fallback)
- synchronized (LoaderClassPath.class) {
- if (moduleClassPath == null)
- moduleClassPath = new ModuleClassPath();
- }
- }
-
- public String toString() {
- Object cl = null;
- if (clref != null)
- cl = clref.get();
-
- return cl == null ? "<null>" : cl.toString();
- }
-
- /**
- * Obtains a class file from the class loader.
- * This method calls <code>getResourceAsStream(String)</code>
- * on the class loader.
- */
- public InputStream openClassfile(String classname) throws NotFoundException {
- String cname = classname.replace('.', '/') + ".class";
- ClassLoader cl = (ClassLoader)clref.get();
- if (cl == null)
- return null; // not found
- else {
- InputStream is = cl.getResourceAsStream(cname);
- if (is == null && doFallback)
- return moduleClassPath.openClassfile(classname);
- else
- return is;
- }
- }
-
- /**
- * Obtains the URL of the specified class file.
- * This method calls <code>getResource(String)</code>
- * on the class loader.
- *
- * @return null if the class file could not be found.
- */
- public URL find(String classname) {
- String cname = classname.replace('.', '/') + ".class";
- ClassLoader cl = (ClassLoader)clref.get();
- if (cl == null)
- return null; // not found
- else {
- URL url = cl.getResource(cname);
- if (url == null && doFallback)
- return moduleClassPath.find(classname);
- else
- return url;
- }
- }
-
- /**
- * Closes this class path.
- */
- public void close() {
- clref = null;
- }
- }
|