Java tutorial
/* * Copyright 2012-2015 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package lodsve.core.condition; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.context.annotation.Condition; import org.springframework.context.annotation.ConditionContext; import org.springframework.core.type.AnnotatedTypeMetadata; import org.springframework.core.type.AnnotationMetadata; import org.springframework.core.type.ClassMetadata; import org.springframework.core.type.MethodMetadata; import org.springframework.util.ClassUtils; import org.springframework.util.StringUtils; /** * Base of all {@link Condition} implementations used with Spring Boot. Provides sensible * logging to help the user diagnose what classes are loaded. * * @author Phillip Webb * @author Greg Turnquist */ public abstract class SpringBootCondition implements Condition { private final Log logger = LogFactory.getLog(getClass()); @Override public final boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) { String classOrMethodName = getClassOrMethodName(metadata); try { ConditionOutcome outcome = getMatchOutcome(context, metadata); logOutcome(classOrMethodName, outcome); recordEvaluation(context, classOrMethodName, outcome); return outcome.isMatch(); } catch (NoClassDefFoundError ex) { throw new IllegalStateException("Could not evaluate condition on " + classOrMethodName + " due to " + ex.getMessage() + " not " + "found. Make sure your own configuration does not rely on " + "that class. This can also happen if you are " + "@ComponentScanning a springframework package (e.g. if you " + "put a @ComponentScan in the default package by mistake)", ex); } catch (RuntimeException ex) { throw new IllegalStateException("Error processing condition on " + getName(metadata), ex); } } private String getName(AnnotatedTypeMetadata metadata) { if (metadata instanceof AnnotationMetadata) { return ((AnnotationMetadata) metadata).getClassName(); } if (metadata instanceof MethodMetadata) { MethodMetadata methodMetadata = (MethodMetadata) metadata; return methodMetadata.getDeclaringClassName() + "." + methodMetadata.getMethodName(); } return metadata.toString(); } private static String getClassOrMethodName(AnnotatedTypeMetadata metadata) { if (metadata instanceof ClassMetadata) { ClassMetadata classMetadata = (ClassMetadata) metadata; return classMetadata.getClassName(); } MethodMetadata methodMetadata = (MethodMetadata) metadata; return methodMetadata.getDeclaringClassName() + "#" + methodMetadata.getMethodName(); } private void logOutcome(String classOrMethodName, ConditionOutcome outcome) { if (this.logger.isTraceEnabled()) { this.logger.trace(getLogMessage(classOrMethodName, outcome)); } } private StringBuilder getLogMessage(String classOrMethodName, ConditionOutcome outcome) { StringBuilder message = new StringBuilder(); message.append("Condition "); message.append(ClassUtils.getShortName(getClass())); message.append(" on "); message.append(classOrMethodName); message.append(outcome.isMatch() ? " matched" : " did not match"); if (StringUtils.hasLength(outcome.getMessage())) { message.append(" due to "); message.append(outcome.getMessage()); } return message; } private void recordEvaluation(ConditionContext context, String classOrMethodName, ConditionOutcome outcome) { if (context.getBeanFactory() != null) { ConditionEvaluationReport.get(context.getBeanFactory()).recordConditionEvaluation(classOrMethodName, this, outcome); } } /** * Determine the outcome of the match along with suitable log output. * * @param context the condition context * @param metadata the annotation metadata * @return the condition outcome */ public abstract ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata); /** * Return true if any of the specified conditions match. * * @param context the context * @param metadata the annotation meta-data * @param conditions conditions to test * @return {@code true} if any condition matches. */ protected final boolean anyMatches(ConditionContext context, AnnotatedTypeMetadata metadata, Condition... conditions) { for (Condition condition : conditions) { if (matches(context, metadata, condition)) { return true; } } return false; } /** * Return true if any of the specified condition matches. * * @param context the context * @param metadata the annotation meta-data * @param condition condition to test * @return {@code true} if the condition matches. */ protected final boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata, Condition condition) { if (condition instanceof SpringBootCondition) { return ((SpringBootCondition) condition).getMatchOutcome(context, metadata).isMatch(); } return condition.matches(context, metadata); } }