org.glowroot.api.weaving.OnBefore Maven / Gradle / Ivy
/*
* Copyright 2012-2014 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.glowroot.api.weaving;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
/**
* Annotates a method in a {@literal @}{@link Pointcut} class that should be run just before each
* method execution picked out by the {@link Pointcut}. Only one method in a
*
* {@literal @}{@code Pointcut} class may be annotated with {@literal @}{@code OnBefore}.
*
* An {@literal @}{@code OnBefore} method can accept parameters annotated with any of the following:
* {@literal @}{@link BindReceiver}, {@literal @}{@link BindParameter},
*
* {@literal @}{@link BindParameterArray} or {@literal @}{@link BindMethodName}.
*
* An {@literal @}{@code OnBefore} method may return {@code void} or a non-{@code void} type. If it
* returns a non-{@code void} type, the value returned by the {@literal @}{@code OnBefore} method is
* called the traveler, and is available as input to subsequent
*
* {@literal @}{@link OnReturn}, {@literal @}{@link OnThrow} and {@literal @}{@link OnAfter} methods
* by annotating a parameter on any of these methods with {@literal @}{@link BindTraveler}.
*/
@Target(METHOD)
@Retention(RUNTIME)
public @interface OnBefore {}