ExceptionResolver.java

/*****************************************************************************
 * Copyright 2011 Zdenko Vrabel
 *
 * 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.zdevra.guice.mvc;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * This interface is used for resolving exceptions which are thrown
 * from controllers. 
 * 
 * The default implementation of resolving in Lime MVC is used {@link GuiceExceptionResolver}.
 * It can be changed easy in @{link MvcModule}'s configureControllers() method.
 * 
 * 
 * 
 * Example:
 * <pre class="prettyprint">
 * public void configureControllers() {
 *    ...
 *    bindException(Custom1Exception.class).toHandler(Custom1ExceptionHandler.class);
 *    bindException(Custom2Exception.class).toHandlerInstance( new Custom2ExceptionHandler() );
 *    ...
 * }
 * </pre>
 *  
 * @see ExceptionHandler
 * @see GuiceExceptionResolver
 * @see MvcModule
 */
public interface ExceptionResolver {

    public static final String DEFAULT_EXCEPTIONHANDLER_NAME = "defaultExceptionHandler";

    /**
     * Method is invoked in {@link MvcDispatcherServlet}, when a controller
     * throw some exception. This method go through all registered
     * exception handlers and invoke correct handler for that exception.
     */
    public abstract void handleException(Throwable t, HttpServlet servlet, HttpServletRequest req, HttpServletResponse resp);
}