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AspectJ tools most notably contains the AspectJ compiler (AJC). AJC applies aspects to Java classes during
compilation, fully replacing Javac for plain Java classes and also compiling native AspectJ or annotation-based
@AspectJ syntax. Furthermore, AJC can weave aspects into existing class files in a post-compile binary weaving step.
This library is a superset of AspectJ weaver and hence also of AspectJ runtime.
/*******************************************************************************
* Copyright (c) 2005 Contributors.
* All rights reserved.
* This program and the accompanying materials are made available
* under the terms of the Eclipse Public License v 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.txt
*
* Contributors:
* initial implementation Alexandre Vasseur
* generic signature update Adrian Colyer
*******************************************************************************/
package org.aspectj.lang;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.InvocationTargetException;
/**
* Handles generic aspectOf method when those are not available in the aspects but added later on
* thru load time weaving.
* Aspects.aspectOf(..) is doing reflective calls to the aspect aspectOf, so for better performance
* consider using ajc compilation of the aspects and using them as a binary dependencies in your project.
*
* @author Alexandre Vasseur
*/
public class Aspects {
private final static Class[] EMPTY_CLASS_ARRAY = new Class[0];
private final static Class[] PEROBJECT_CLASS_ARRAY = new Class[]{Object.class};
private final static Class[] PERTYPEWITHIN_CLASS_ARRAY = new Class[]{Class.class};
private final static Object[] EMPTY_OBJECT_ARRAY = new Object[0];
private final static String ASPECTOF = "aspectOf";
private final static String HASASPECT = "hasAspect";
/**
* @param the expected class of the aspect
* @param aspectClass the aspect class
* @return the singleton aspect or the percflow / percflowbelow associated with the current thread
* @throws NoAspectBoundException if no such aspect
*/
public static T aspectOf(Class aspectClass) throws NoAspectBoundException {
try {
return (T) getSingletonOrThreadAspectOf(aspectClass).invoke(null, EMPTY_OBJECT_ARRAY);
} catch (InvocationTargetException e) {
//FIXME asc Highly temporary change to see what the build makes of it - dont use 1.4 APIs
throw new NoAspectBoundException(aspectClass.getName(), e);//e.getCause());
} catch (Exception e) {
throw new NoAspectBoundException(aspectClass.getName(), e);
}
}
/**
* @param the expected class of the aspect
* @param aspectClass the aspect class
* @param perObject the this/target object for which to look for an aspect instance
* @return the associated perthis / pertarget aspect instance
* @throws NoAspectBoundException if no such aspect, or no aspect bound
*/
public static T aspectOf(Class aspectClass, Object perObject) throws NoAspectBoundException {
try {
return (T) getPerObjectAspectOf(aspectClass).invoke(null, new Object[]{perObject});
} catch (InvocationTargetException e) {
//FIXME asc Highly temporary change to see what the build makes of it - dont use 1.4 APIs
throw new NoAspectBoundException(aspectClass.getName(), e);//e.getCause());
} catch (Exception e) {
throw new NoAspectBoundException(aspectClass.getName(), e);
}
}
/**
* @param the expected class of the aspect
* @param aspectClass the aspect class
* @param perTypeWithin the class for which to search for an aspect instance
* @return the associated aspect instance
* @throws NoAspectBoundException if no such aspect, or no aspect bound
*/
public static T aspectOf(Class aspectClass, Class perTypeWithin) throws NoAspectBoundException {
try {
return (T) getPerTypeWithinAspectOf(aspectClass).invoke(null, new Object[]{perTypeWithin});
} catch (InvocationTargetException e) {
// FIXME asc Highly temporary change to see what the build makes of it - dont use 1.4 APIs
throw new NoAspectBoundException(aspectClass.getName(), e);//e.getCause());
} catch (Exception e) {
throw new NoAspectBoundException(aspectClass.getName(), e);
}
}
/**
* @param aspectClass the aspect class
* @return true if singleton aspect or percflow / percflowbelow aspect is bound
* @throws NoAspectBoundException if not bound
*/
public static boolean hasAspect(Class aspectClass) throws NoAspectBoundException {
try {
return (Boolean) getSingletonOrThreadHasAspect(aspectClass).invoke(null, EMPTY_OBJECT_ARRAY);
} catch (Exception e) {
return false;
}
}
/**
* @param aspectClass the aspect class
* @param perObject the this/target object for which to look for an aspect instance
* @return true if the perthis / pertarget aspect is bound
* @throws NoAspectBoundException if not bound
*/
public static boolean hasAspect(Class aspectClass, Object perObject) throws NoAspectBoundException {
try {
return (Boolean) getPerObjectHasAspect(aspectClass).invoke(null, new Object[]{perObject});
} catch (Exception e) {
return false;
}
}
/**
* @param aspectClass the aspect class
* @param perTypeWithin class
* @return true if the pertypewithin aspect is bound
* @throws NoAspectBoundException if not bound
*/
public static boolean hasAspect(Class aspectClass, Class perTypeWithin) throws NoAspectBoundException {
try {
return (Boolean) getPerTypeWithinHasAspect(aspectClass).invoke(null, new Object[]{perTypeWithin});
} catch (Exception e) {
return false;
}
}
// -- aspectOf
private static Method getSingletonOrThreadAspectOf(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(ASPECTOF, EMPTY_CLASS_ARRAY);
return checkAspectOf(method, aspectClass);
}
private static Method getPerObjectAspectOf(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(ASPECTOF, PEROBJECT_CLASS_ARRAY);
return checkAspectOf(method, aspectClass);
}
private static Method getPerTypeWithinAspectOf(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(ASPECTOF, PERTYPEWITHIN_CLASS_ARRAY);
return checkAspectOf(method, aspectClass);
}
private static Method checkAspectOf(Method method, Class aspectClass) throws NoSuchMethodException {
method.setAccessible(true);
if (!method.isAccessible()
|| !Modifier.isPublic(method.getModifiers())
|| !Modifier.isStatic(method.getModifiers())) {
throw new NoSuchMethodException(aspectClass.getName() + ".aspectOf(..) is not accessible public static");
}
return method;
}
// -- hasAspect
private static Method getSingletonOrThreadHasAspect(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(HASASPECT, EMPTY_CLASS_ARRAY);
return checkHasAspect(method, aspectClass);
}
private static Method getPerObjectHasAspect(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(HASASPECT, PEROBJECT_CLASS_ARRAY);
return checkHasAspect(method, aspectClass);
}
private static Method getPerTypeWithinHasAspect(Class aspectClass) throws NoSuchMethodException {
Method method = aspectClass.getDeclaredMethod(HASASPECT, PERTYPEWITHIN_CLASS_ARRAY);
return checkHasAspect(method, aspectClass);
}
private static Method checkHasAspect(Method method, Class aspectClass) throws NoSuchMethodException {
method.setAccessible(true);
if (!method.isAccessible()
|| !Modifier.isPublic(method.getModifiers())
|| !Modifier.isStatic(method.getModifiers())) {
throw new NoSuchMethodException(aspectClass.getName() + ".hasAspect(..) is not accessible public static");
}
return method;
}
}