Spring AOPソース分析(七)ProxyFactoryBean紹介
この文章の中でSpringの自分のAOPを話して、どの方式がSpringの自分で実現するAOPかをはっきりさせて、どの方式がSpringがaspectjのAOPを導入するのですか?Spring自身のAOPが実現したのはProxyFactoryBeanです.まず使用例を見てください.インターフェースAService、実現類AServiceImpl、MyBefore Adviceを教えます.
public interface AService {
public void fooA(String _msg);
public void barA();
}
public class AServiceImpl implements AService{
@Override
public void fooA(String _msg) {
System.out.println("AServiceImpl.fooA(msg:"+_msg+")");
}
@Override
public void barA() {
System.out.println("AServiceImpl.barA()");
}
}
public class MyBeforeAdvice implements MethodBeforeAdvice{
@Override
public void before(Method method, Object[] args, Object target)
throws Throwable {
System.out.println("run my before advice");
}
}
<bean id="aServiceImpl" class="com.lg.aop.service.impl.AServiceImpl"/>
<bean id="myBeforAdvice" class="com.lg.aop.MyBeforeAdvice"/>
<bean class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="interfaces" value="com.lg.aop.service.AService"/>
<property name="target">
<ref bean="aServiceImpl"/>
</property>
<property name="interceptorNames">
<list>
<value>myBeforAdvice</value>
</list>
</property>
</bean>
@Autowired
private AService aService;
@Test
public void testAOP(){
aService.barA();
}
No qualifying bean of type [com.lg.aop.service.AService] is defined: expected single matching bean but found 2: aServiceImpl,org.springframework.aop.framework.ProxyFactoryBean#0
/**
* Interface to be implemented by objects used within a {@link BeanFactory}
* which are themselves factories. If a bean implements this interface,
* it is used as a factory for an object to expose, not directly as a bean
* instance that will be exposed itself.
*
* <p><b>NB: A bean that implements this interface cannot be used as a
* normal bean.</b> A FactoryBean is defined in a bean style, but the
* object exposed for bean references ({@link #getObject()} is always
* the object that it creates.
<bean id="aServiceImplProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
@Resource(name="aServiceImplProxy")
private AService aService;
run my before advice
AServiceImpl.barA()
public Object getObject() throws BeansException {
// 1
initializeAdvisorChain();
if (isSingleton()) {
// 2
return getSingletonInstance();
}
else {
if (this.targetName == null) {
logger.warn("Using non-singleton proxies with singleton targets is often undesirable. " +
"Enable prototype proxies by setting the 'targetName' property.");
}
return newPrototypeInstance();
}
}
private synchronized void initializeAdvisorChain() throws AopConfigException, BeansException {
if (this.advisorChainInitialized) {
return;
}
if (!ObjectUtils.isEmpty(this.interceptorNames)) {
if (this.beanFactory == null) {
throw new IllegalStateException("No BeanFactory available anymore (probably due to serialization) " +
"- cannot resolve interceptor names " + Arrays.asList(this.interceptorNames));
}
// Globals can't be last unless we specified a targetSource using the property...
if (this.interceptorNames[this.interceptorNames.length - 1].endsWith(GLOBAL_SUFFIX) &&
this.targetName == null && this.targetSource == EMPTY_TARGET_SOURCE) {
throw new AopConfigException("Target required after globals");
}
// Materialize interceptor chain from bean names.
for (String name : this.interceptorNames) {
if (logger.isTraceEnabled()) {
logger.trace("Configuring advisor or advice '" + name + "'");
}
if (name.endsWith(GLOBAL_SUFFIX)) {
if (!(this.beanFactory instanceof ListableBeanFactory)) {
throw new AopConfigException(
"Can only use global advisors or interceptors with a ListableBeanFactory");
}
addGlobalAdvisor((ListableBeanFactory) this.beanFactory,
name.substring(0, name.length() - GLOBAL_SUFFIX.length()));
}
else {
// If we get here, we need to add a named interceptor.
// We must check if it's a singleton or prototype.
Object advice;
if (this.singleton || this.beanFactory.isSingleton(name)) {
// Add the real Advisor/Advice to the chain.
advice = this.beanFactory.getBean(name);
}
else {
// It's a prototype Advice or Advisor: replace with a prototype.
// Avoid unnecessary creation of prototype bean just for advisor chain initialization.
advice = new PrototypePlaceholderAdvisor(name);
}
addAdvisorOnChainCreation(advice, name);
}
}
}
this.advisorChainInitialized = true;
}
<bean id="proxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="service"/>
<property name="interceptorNames">
<list>
<value>global*</value>
</list>
</property>
</bean>
<bean id="global_debug" class="org.springframework.aop.interceptor.DebugInterceptor"/>
<bean id="global_performance" class="org.springframework.aop.interceptor.PerformanceMonitorInterceptor"/>
private void addAdvisorOnChainCreation(Object next, String name) {
// We need to convert to an Advisor if necessary so that our source reference
// matches what we find from superclass interceptors.
Advisor advisor = namedBeanToAdvisor(next);
if (logger.isTraceEnabled()) {
logger.trace("Adding advisor with name '" + name + "'");
}
addAdvisor(advisor);
}
private Advisor namedBeanToAdvisor(Object next) {
try {
return this.advisorAdapterRegistry.wrap(next);
}
}
}
public Advisor wrap(Object adviceObject) throws UnknownAdviceTypeException {
if (adviceObject instanceof Advisor) {
return (Advisor) adviceObject;
}
if (!(adviceObject instanceof Advice)) {
throw new UnknownAdviceTypeException(adviceObject);
}
Advice advice = (Advice) adviceObject;
if (advice instanceof MethodInterceptor) {
// So well-known it doesn't even need an adapter.
return new DefaultPointcutAdvisor(advice);
}
for (AdvisorAdapter adapter : this.adapters) {
// Check that it is supported.
if (adapter.supportsAdvice(advice)) {
return new DefaultPointcutAdvisor(advice);
}
}
throw new UnknownAdviceTypeException(advice);
}