/*
* Copyright 2002-2014 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 org.springframework.web.method;
import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.OrderUtils;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.ControllerAdvice;
/**
* Encapsulates information about an {@linkplain ControllerAdvice @ControllerAdvice}
* Spring-managed bean without necessarily requiring it to be instantiated.
*
* <p>The {@link #findAnnotatedBeans(ApplicationContext)} method can be used to discover
* such beans. However, an {@code ControllerAdviceBean} may be created from
* any object, including ones without an {@code @ControllerAdvice}.
*
* @author Rossen Stoyanchev
* @author Brian Clozel
* @since 3.2
*/
public class ControllerAdviceBean implements Ordered {
private static final Log logger = LogFactory.getLog(ControllerAdviceBean.class);
private final Object bean;
private final int order;
private final BeanFactory beanFactory;
private final List<Package> basePackages = new ArrayList<Package>();
private final List<Class<? extends Annotation>> annotations = new ArrayList<Class<? extends Annotation>>();
private final List<Class<?>> assignableTypes = new ArrayList<Class<?>>();
/**
* Create an instance using the given bean name.
* @param beanName the name of the bean
* @param beanFactory a BeanFactory that can be used later to resolve the bean
*/
public ControllerAdviceBean(String beanName, BeanFactory beanFactory) {
Assert.hasText(beanName, "Bean name must not be null");
Assert.notNull(beanFactory, "BeanFactory must not be null");
if (!beanFactory.containsBean(beanName)) {
throw new IllegalArgumentException(
"BeanFactory [" + beanFactory + "] does not contain bean with name '" + beanName + "'");
}
this.bean = beanName;
this.beanFactory = beanFactory;
Class<?> beanType = this.beanFactory.getType(beanName);
this.order = initOrderFromBeanType(beanType);
ControllerAdvice annotation = AnnotationUtils.findAnnotation(beanType,ControllerAdvice.class);
Assert.notNull(annotation, "BeanType [" + beanType.getName() + "] is not annotated @ControllerAdvice");
this.basePackages.addAll(initBasePackagesFromBeanType(beanType, annotation));
this.annotations.addAll(Arrays.asList(annotation.annotations()));
this.assignableTypes.addAll(Arrays.asList(annotation.assignableTypes()));
}
/**
* Create an instance using the given bean instance.
* @param bean the bean
*/
public ControllerAdviceBean(Object bean) {
Assert.notNull(bean, "Bean must not be null");
this.bean = bean;
this.order = initOrderFromBean(bean);
Class<?> beanType = bean.getClass();
ControllerAdvice annotation = AnnotationUtils.findAnnotation(beanType,ControllerAdvice.class);
Assert.notNull(annotation, "Bean type [" + beanType.getName() + "] is not annotated @ControllerAdvice");
this.basePackages.addAll(initBasePackagesFromBeanType(beanType, annotation));
this.annotations.addAll(Arrays.asList(annotation.annotations()));
this.assignableTypes.addAll(Arrays.asList(annotation.assignableTypes()));
this.beanFactory = null;
}
/**
* Returns the order value extracted from the {@link ControllerAdvice}
* annotation or {@link Ordered#LOWEST_PRECEDENCE} otherwise.
*/
@Override
public int getOrder() {
return this.order;
}
/**
* Returns the type of the contained bean.
* If the bean type is a CGLIB-generated class, the original, user-defined class is returned.
*/
public Class<?> getBeanType() {
Class<?> clazz = (this.bean instanceof String ?
this.beanFactory.getType((String) this.bean) : this.bean.getClass());
return ClassUtils.getUserClass(clazz);
}
/**
* Return a bean instance if necessary resolving the bean name through the BeanFactory.
*/
public Object resolveBean() {
return (this.bean instanceof String ? this.beanFactory.getBean((String) this.bean) : this.bean);
}
/**
* Checks whether the given bean type should be assisted by this
* {@code @ControllerAdvice} instance.
* @param beanType the type of the bean to check
* @see org.springframework.web.bind.annotation.ControllerAdvice
* @since 4.0
*/
public boolean isApplicableToBeanType(Class<?> beanType) {
if (!hasSelectors()) {
return true;
}
else if (beanType != null) {
for (Class<?> clazz : this.assignableTypes) {
if (ClassUtils.isAssignable(clazz, beanType)) {
return true;
}
}
for (Class<? extends Annotation> annotationClass : this.annotations) {
if (AnnotationUtils.findAnnotation(beanType, annotationClass) != null) {
return true;
}
}
String packageName = beanType.getPackage().getName();
for (Package basePackage : this.basePackages) {
if (packageName.startsWith(basePackage.getName())) {
return true;
}
}
}
return false;
}
private boolean hasSelectors() {
return (!this.basePackages.isEmpty() || !this.annotations.isEmpty() || !this.assignableTypes.isEmpty());
}
@Override
public boolean equals(Object other) {
return (this == other ||
(other instanceof ControllerAdviceBean && this.bean.equals(((ControllerAdviceBean) other).bean)));
}
@Override
public int hashCode() {
return this.bean.hashCode();
}
@Override
public String toString() {
return this.bean.toString();
}
/**
* Find the names of beans annotated with
* {@linkplain ControllerAdvice @ControllerAdvice} in the given
* ApplicationContext and wrap them as {@code ControllerAdviceBean} instances.
*/
public static List<ControllerAdviceBean> findAnnotatedBeans(ApplicationContext applicationContext) {
List<ControllerAdviceBean> beans = new ArrayList<ControllerAdviceBean>();
for (String name : BeanFactoryUtils.beanNamesForTypeIncludingAncestors(applicationContext, Object.class)) {
if (applicationContext.findAnnotationOnBean(name, ControllerAdvice.class) != null) {
beans.add(new ControllerAdviceBean(name, applicationContext));
}
}
return beans;
}
private static int initOrderFromBean(Object bean) {
return (bean instanceof Ordered ? ((Ordered) bean).getOrder() : initOrderFromBeanType(bean.getClass()));
}
private static int initOrderFromBeanType(Class<?> beanType) {
return OrderUtils.getOrder(beanType, Ordered.LOWEST_PRECEDENCE);
}
private static List<Package> initBasePackagesFromBeanType(Class<?> beanType, ControllerAdvice annotation) {
List<Package> basePackages = new ArrayList<Package>();
List<String> basePackageNames = new ArrayList<String>();
basePackageNames.addAll(Arrays.asList(annotation.value()));
basePackageNames.addAll(Arrays.asList(annotation.basePackages()));
for (String pkgName : basePackageNames) {
if (StringUtils.hasText(pkgName)) {
Package pkg = Package.getPackage(pkgName);
if (pkg != null) {
basePackages.add(pkg);
}
else {
logger.warn("Package [" + pkgName + "] was not found, see [" + beanType.getName() + "]");
}
}
}
for (Class<?> markerClass : annotation.basePackageClasses()) {
Package pack = markerClass.getPackage();
if (pack != null) {
basePackages.add(pack);
}
else {
logger.warn("Package was not found for class [" + markerClass.getName() +
"], see [" + beanType.getName() + "]");
}
}
return basePackages;
}
}