Java tutorial
/* * Copyright 2002-2018 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 * * https://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 org.springframework.beans.factory.config; import java.util.LinkedHashMap; import java.util.Map; import org.springframework.beans.BeanUtils; import org.springframework.beans.BeansException; import org.springframework.beans.factory.BeanClassLoaderAware; import org.springframework.core.Ordered; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.ClassUtils; /** * Simple {@link BeanFactoryPostProcessor} implementation that registers * custom {@link Scope Scope(s)} with the containing {@link ConfigurableBeanFactory}. * * <p>Will register all of the supplied {@link #setScopes(java.util.Map) scopes} * with the {@link ConfigurableListableBeanFactory} that is passed to the * {@link #postProcessBeanFactory(ConfigurableListableBeanFactory)} method. * * <p>This class allows for <i>declarative</i> registration of custom scopes. * Alternatively, consider implementing a custom {@link BeanFactoryPostProcessor} * that calls {@link ConfigurableBeanFactory#registerScope} programmatically. * * @author Juergen Hoeller * @author Rick Evans * @since 2.0 * @see ConfigurableBeanFactory#registerScope */ public class CustomScopeConfigurer implements BeanFactoryPostProcessor, BeanClassLoaderAware, Ordered { @Nullable private Map<String, Object> scopes; private int order = Ordered.LOWEST_PRECEDENCE; @Nullable private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader(); /** * Specify the custom scopes that are to be registered. * <p>The keys indicate the scope names (of type String); each value * is expected to be the corresponding custom {@link Scope} instance * or class name. */ public void setScopes(Map<String, Object> scopes) { this.scopes = scopes; } /** * Add the given scope to this configurer's map of scopes. * @param scopeName the name of the scope * @param scope the scope implementation * @since 4.1.1 */ public void addScope(String scopeName, Scope scope) { if (this.scopes == null) { this.scopes = new LinkedHashMap<>(1); } this.scopes.put(scopeName, scope); } public void setOrder(int order) { this.order = order; } @Override public int getOrder() { return this.order; } @Override public void setBeanClassLoader(@Nullable ClassLoader beanClassLoader) { this.beanClassLoader = beanClassLoader; } @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException { if (this.scopes != null) { this.scopes.forEach((scopeKey, value) -> { if (value instanceof Scope) { beanFactory.registerScope(scopeKey, (Scope) value); } else if (value instanceof Class) { Class<?> scopeClass = (Class<?>) value; Assert.isAssignable(Scope.class, scopeClass, "Invalid scope class"); beanFactory.registerScope(scopeKey, (Scope) BeanUtils.instantiateClass(scopeClass)); } else if (value instanceof String) { Class<?> scopeClass = ClassUtils.resolveClassName((String) value, this.beanClassLoader); Assert.isAssignable(Scope.class, scopeClass, "Invalid scope class"); beanFactory.registerScope(scopeKey, (Scope) BeanUtils.instantiateClass(scopeClass)); } else { throw new IllegalArgumentException("Mapped value [" + value + "] for scope key [" + scopeKey + "] is not an instance of required type [" + Scope.class.getName() + "] or a corresponding Class or String value indicating a Scope implementation"); } }); } } }