001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018package org.apache.bcel.util; 019 020import java.lang.ref.SoftReference; 021import java.util.HashMap; 022import java.util.Map; 023 024import org.apache.bcel.classfile.JavaClass; 025 026/** 027 * This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded from the file systems using the paths 028 * specified in the given class path. By default, this is the value returned by ClassPath.getClassPath(). This repository holds onto classes with 029 * SoftReferences, and will reload as needed, in cases where memory sizes are important. 030 * 031 * @see org.apache.bcel.Repository 032 */ 033public class MemorySensitiveClassPathRepository extends AbstractClassPathRepository { 034 035 private final Map<String, SoftReference<JavaClass>> _loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS 036 037 public MemorySensitiveClassPathRepository(final ClassPath path) { 038 super(path); 039 } 040 041 /** 042 * Store a new JavaClass instance into this Repository. 043 */ 044 @Override 045 public void storeClass(final JavaClass clazz) { 046 // Not calling super.storeClass because this subclass maintains the mapping. 047 _loadedClasses.put(clazz.getClassName(), new SoftReference<>(clazz)); 048 clazz.setRepository(this); 049 } 050 051 /** 052 * Remove class from repository 053 */ 054 @Override 055 public void removeClass(final JavaClass clazz) { 056 _loadedClasses.remove(clazz.getClassName()); 057 } 058 059 /** 060 * Find an already defined (cached) JavaClass object by name. 061 */ 062 @Override 063 public JavaClass findClass(final String className) { 064 final SoftReference<JavaClass> ref = _loadedClasses.get(className); 065 if (ref == null) { 066 return null; 067 } 068 return ref.get(); 069 } 070 071 /** 072 * Clear all entries from cache. 073 */ 074 @Override 075 public void clear() { 076 _loadedClasses.clear(); 077 } 078}