org.aopalliance.intercept.FieldInterceptor Maven / Gradle / Ivy
package org.aopalliance.intercept;
/**
* Intercepts field access on a target object.
*
* The user should implement the {@link #set(FieldAccess)} and
* {@link #get(FieldAccess)} methods to modify the original
* behavior. E.g. the following class implements a tracing interceptor
* (traces the accesses to the intercepted field(s)):
*
*
* class TracingInterceptor implements FieldInterceptor {
*
* Object set(FieldAccess fa) throws Throwable {
* System.out.println("field "+fa.getField()+" is set with value "+
* fa.getValueToSet());
* Object ret=fa.proceed();
* System.out.println("field "+fa.getField()+" was set to value "+ret);
* return ret;
* }
*
* Object get(FieldAccess fa) throws Throwable {
* System.out.println("field "+fa.getField()+" is about to be read");
* Object ret=fa.proceed();
* System.out.println("field "+fa.getField()+" was read; value is "+ret);
* return ret;
* }
* }
* */
public interface FieldInterceptor extends Interceptor
{
/**
* Do the stuff you want to do before and after the
* field is getted.
*
* Polite implementations would certainly like to call
* {@link Joinpoint#proceed()}.
*
* @param fieldRead the joinpoint that corresponds to the field
* read
* @return the result of the field read {@link
* Joinpoint#proceed()}, might be intercepted by the
* interceptor.
*
* @throws Throwable if the interceptors or the
* target-object throws an exception. */
Object get(FieldAccess fieldRead) throws Throwable;
/**
* Do the stuff you want to do before and after the
* field is setted.
*
*
Polite implementations would certainly like to implement
* {@link Joinpoint#proceed()}.
*
* @param fieldWrite the joinpoint that corresponds to the field
* write
* @return the result of the field set {@link
* Joinpoint#proceed()}, might be intercepted by the
* interceptor.
*
* @throws Throwable if the interceptors or the
* target-object throws an exception. */
Object set(FieldAccess fieldWrite) throws Throwable;
}