001/*
002 * Copyright 2002-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.core.type.classreading;
018
019import java.io.FileNotFoundException;
020import java.io.IOException;
021
022import org.springframework.core.io.DefaultResourceLoader;
023import org.springframework.core.io.Resource;
024import org.springframework.core.io.ResourceLoader;
025import org.springframework.lang.Nullable;
026import org.springframework.util.ClassUtils;
027
028/**
029 * Simple implementation of the {@link MetadataReaderFactory} interface,
030 * creating a new ASM {@link org.springframework.asm.ClassReader} for every request.
031 *
032 * @author Juergen Hoeller
033 * @since 2.5
034 */
035public class SimpleMetadataReaderFactory implements MetadataReaderFactory {
036
037        private final ResourceLoader resourceLoader;
038
039
040        /**
041         * Create a new SimpleMetadataReaderFactory for the default class loader.
042         */
043        public SimpleMetadataReaderFactory() {
044                this.resourceLoader = new DefaultResourceLoader();
045        }
046
047        /**
048         * Create a new SimpleMetadataReaderFactory for the given resource loader.
049         * @param resourceLoader the Spring ResourceLoader to use
050         * (also determines the ClassLoader to use)
051         */
052        public SimpleMetadataReaderFactory(@Nullable ResourceLoader resourceLoader) {
053                this.resourceLoader = (resourceLoader != null ? resourceLoader : new DefaultResourceLoader());
054        }
055
056        /**
057         * Create a new SimpleMetadataReaderFactory for the given class loader.
058         * @param classLoader the ClassLoader to use
059         */
060        public SimpleMetadataReaderFactory(@Nullable ClassLoader classLoader) {
061                this.resourceLoader =
062                                (classLoader != null ? new DefaultResourceLoader(classLoader) : new DefaultResourceLoader());
063        }
064
065
066        /**
067         * Return the ResourceLoader that this MetadataReaderFactory has been
068         * constructed with.
069         */
070        public final ResourceLoader getResourceLoader() {
071                return this.resourceLoader;
072        }
073
074
075        @Override
076        public MetadataReader getMetadataReader(String className) throws IOException {
077                try {
078                        String resourcePath = ResourceLoader.CLASSPATH_URL_PREFIX +
079                                        ClassUtils.convertClassNameToResourcePath(className) + ClassUtils.CLASS_FILE_SUFFIX;
080                        Resource resource = this.resourceLoader.getResource(resourcePath);
081                        return getMetadataReader(resource);
082                }
083                catch (FileNotFoundException ex) {
084                        // Maybe an inner class name using the dot name syntax? Need to use the dollar syntax here...
085                        // ClassUtils.forName has an equivalent check for resolution into Class references later on.
086                        int lastDotIndex = className.lastIndexOf('.');
087                        if (lastDotIndex != -1) {
088                                String innerClassName =
089                                                className.substring(0, lastDotIndex) + '$' + className.substring(lastDotIndex + 1);
090                                String innerClassResourcePath = ResourceLoader.CLASSPATH_URL_PREFIX +
091                                                ClassUtils.convertClassNameToResourcePath(innerClassName) + ClassUtils.CLASS_FILE_SUFFIX;
092                                Resource innerClassResource = this.resourceLoader.getResource(innerClassResourcePath);
093                                if (innerClassResource.exists()) {
094                                        return getMetadataReader(innerClassResource);
095                                }
096                        }
097                        throw ex;
098                }
099        }
100
101        @Override
102        public MetadataReader getMetadataReader(Resource resource) throws IOException {
103                return new SimpleMetadataReader(resource, this.resourceLoader.getClassLoader());
104        }
105
106}