如何访问建议方法的返回对象实例

Question

我使用spring AOP来建议我的服务方法，尤其是返回对象的方法，我希望在建议处理期间可以访问该对象。

我的配置工作正常，没有问题。

这里的谏方法的签名，方法返回一个基于方法参数中的数据的新实例，所以参数是不可用的

@Traceable(ETraceableMessages.SAUVER_APPORTEUR) 
public ElementNiveauUn save(ElementNiveauUn apporteur) throws ATPBusinessException { 
    String identifiant = instanceService.sauverInstance(null, apporteur); 
    List<String> extensions = new ArrayList<String>(); 
    extensions.add(ELEMENTSCONTENUS); 
    extensions.add(TYPEELEMENT); 
    extensions.add(VERSIONING); 
    extensions.add(PARAMETRAGES); 
    extensions.add(PARAMETRAGES + "." + PARAMETRES); 
    return (ElementNiveauUn) instanceService.lireInstanceParId(identifiant, extensions.toArray(new String[]{})); 
} 

这里就是我想知道做

@Around(value = "execution(elementNiveauUn fr.generali.nova.atp.service.metier.impl.*.*(..)) && @annotation(traceable) && args(element)", argNames = "element,traceable") 
public void serviceLayerTraceAdviceBasedElementInstanceAfter2(final ProceedingJoinPoint pjp, 
       final ElementNiveauUn element, final Traceable traceable) throws SecurityException, 
       NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException { 

    // current user 
    String currentUserId = findCurrentUserId(); 

    // wether user is found or not 
    boolean isUserFound = StringUtils.isBlank(currentUserId); 

    // retrieve the oid of the returning type 
    MethodSignature signature = (MethodSignature) pjp.getSignature(); 
    Class<ElementNiveauUn> returnType = signature.getReturnType(); 

    Method[] methods = returnType.getMethods(); 
    Method method = returnType.getMethod("getOid", (Class<?>[]) null); 
    String oid = (String) method.invoke(null, (Object[]) null); 

    // log to database 
    simpleTraceService.trace(element.getOid(), element.getVersioning().toString(), traceable.value(), 
        isUserFound ? UTILISATEUR_NON_TROUVE : currentUserId); 
} 

我的问题是，这行代码

Class<ElementNiveauUn> returnType = signature.getReturnType(); 

允许我有acces秒到不以实例

Answer 1

返回类型，因为你有一个各地建议，你需要调用pjp.proceed()为了执行被劝的方法，并返回其值：

@Around(...) 
public Object serviceLayerTraceAdviceBasedElementInstanceAfter2(final ProceedingJoinPoint pjp, 
        final ElementNiveauUn element, final Traceable traceable) throws SecurityException, 
        NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException { 
    ... 
    Object result = pjp.proceed(); 
    ... 
    return result; 
}