001/* 002 * Copyright 2002-2019 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.test.context.support; 018 019import java.lang.reflect.Modifier; 020import java.util.ArrayList; 021import java.util.List; 022 023import org.apache.commons.logging.Log; 024import org.apache.commons.logging.LogFactory; 025 026import org.springframework.context.annotation.Configuration; 027import org.springframework.core.annotation.AnnotatedElementUtils; 028import org.springframework.lang.Nullable; 029import org.springframework.test.context.SmartContextLoader; 030import org.springframework.util.Assert; 031import org.springframework.util.ClassUtils; 032 033/** 034 * Utility methods for {@link SmartContextLoader SmartContextLoaders} that deal 035 * with component classes (e.g., {@link Configuration @Configuration} classes). 036 * 037 * @author Sam Brannen 038 * @since 3.2 039 */ 040public abstract class AnnotationConfigContextLoaderUtils { 041 042 private static final Log logger = LogFactory.getLog(AnnotationConfigContextLoaderUtils.class); 043 044 045 /** 046 * Detect the default configuration classes for the supplied test class. 047 * <p>The returned class array will contain all static nested classes of 048 * the supplied class that meet the requirements for {@code @Configuration} 049 * class implementations as specified in the documentation for 050 * {@link Configuration @Configuration}. 051 * <p>The implementation of this method adheres to the contract defined in the 052 * {@link org.springframework.test.context.SmartContextLoader SmartContextLoader} 053 * SPI. Specifically, this method uses introspection to detect default 054 * configuration classes that comply with the constraints required of 055 * {@code @Configuration} class implementations. If a potential candidate 056 * configuration class does not meet these requirements, this method will log a 057 * debug message, and the potential candidate class will be ignored. 058 * @param declaringClass the test class that declared {@code @ContextConfiguration} 059 * @return an array of default configuration classes, potentially empty but 060 * never {@code null} 061 */ 062 public static Class<?>[] detectDefaultConfigurationClasses(Class<?> declaringClass) { 063 Assert.notNull(declaringClass, "Declaring class must not be null"); 064 065 List<Class<?>> configClasses = new ArrayList<>(); 066 067 for (Class<?> candidate : declaringClass.getDeclaredClasses()) { 068 if (isDefaultConfigurationClassCandidate(candidate)) { 069 configClasses.add(candidate); 070 } 071 else { 072 if (logger.isDebugEnabled()) { 073 logger.debug(String.format( 074 "Ignoring class [%s]; it must be static, non-private, non-final, and annotated " + 075 "with @Configuration to be considered a default configuration class.", 076 candidate.getName())); 077 } 078 } 079 } 080 081 if (configClasses.isEmpty()) { 082 if (logger.isInfoEnabled()) { 083 logger.info(String.format("Could not detect default configuration classes for test class [%s]: " + 084 "%s does not declare any static, non-private, non-final, nested classes " + 085 "annotated with @Configuration.", declaringClass.getName(), declaringClass.getSimpleName())); 086 } 087 } 088 089 return ClassUtils.toClassArray(configClasses); 090 } 091 092 /** 093 * Determine if the supplied {@link Class} meets the criteria for being 094 * considered a <em>default configuration class</em> candidate. 095 * <p>Specifically, such candidates: 096 * <ul> 097 * <li>must not be {@code null}</li> 098 * <li>must not be {@code private}</li> 099 * <li>must not be {@code final}</li> 100 * <li>must be {@code static}</li> 101 * <li>must be annotated or meta-annotated with {@code @Configuration}</li> 102 * </ul> 103 * @param clazz the class to check 104 * @return {@code true} if the supplied class meets the candidate criteria 105 */ 106 private static boolean isDefaultConfigurationClassCandidate(@Nullable Class<?> clazz) { 107 return (clazz != null && isStaticNonPrivateAndNonFinal(clazz) && 108 AnnotatedElementUtils.hasAnnotation(clazz, Configuration.class)); 109 } 110 111 private static boolean isStaticNonPrivateAndNonFinal(Class<?> clazz) { 112 Assert.notNull(clazz, "Class must not be null"); 113 int modifiers = clazz.getModifiers(); 114 return (Modifier.isStatic(modifiers) && !Modifier.isPrivate(modifiers) && !Modifier.isFinal(modifiers)); 115 } 116 117}