/***
* Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
* All rights reserved.
*
* 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 br.com.caelum.vraptor.interceptor;
import br.com.caelum.vraptor.InterceptionException;
import br.com.caelum.vraptor.Lazy;
import br.com.caelum.vraptor.core.InterceptorStack;
import br.com.caelum.vraptor.resource.ResourceMethod;
/**
* Whenever an interceptor accepts a resource method, its intercept method is
* invoked to intercept the process of request parsing in order to allow the
* software to do some specific tasks.<br>
* Common usage for interceptors for end-users (end-programmers) are security
* constraint checks, database session (open session in view) opening and much
* more.
*
* If you have an interceptor A which depends on an interceptor B, i.e, interceptor
* B must be executed before interceptor A, use {@link InterceptorSequence}.
*
* If the {@link Interceptor#accepts(ResourceMethod)} method only depends on received
* {@link ResourceMethod}, you can annotate the interceptor with @{@link Lazy}, so the
* Interceptor will only be instantiated if the accepts returns true.
* You should not use @Lazy if accepts is constant, or depends on any constructor parameter.
*
* @see InterceptorSequence
* @see Lazy
* @author Guilherme Silveira
*/
public interface Interceptor {
void intercept(InterceptorStack stack, ResourceMethod method, Object resourceInstance) throws InterceptionException;
boolean accepts(ResourceMethod method);
}