app/src/main/java/org/apache/roller/weblogger/ui/struts2/util/UIActionPrepareInterceptor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  The ASF licenses this file to You
 * 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.  For additional information regarding
 * copyright in this work, please see the NOTICE file in the top level
 * directory of this distribution.
 */

package org.apache.roller.weblogger.ui.struts2.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;

/**
 * A struts2 interceptor for doing custom prepare logic.
 */
public class UIActionPrepareInterceptor extends MethodFilterInterceptor {

    private static final long serialVersionUID = 7770184756145702592L;
    private static Log log = LogFactory
            .getLog(UIActionPrepareInterceptor.class);

    public String doIntercept(ActionInvocation invocation) throws Exception {

        if (log.isDebugEnabled()) {
            log.debug("Entering UIActionPrepareInterceptor");
        }

        final Object action = invocation.getAction();

        // is this one of our own UIAction classes?
        if (action instanceof UIActionPreparable) {

            if (log.isDebugEnabled()) {
                log.debug("action is UIActionPreparable, calling myPrepare() method");
            }

            UIActionPreparable theAction = (UIActionPreparable) action;
            theAction.myPrepare();
        }

        return invocation.invoke();
    }

}