BaseAction.java

/**
 *  Copyright (c) 2009-2010 Misys Open Source Solutions (MOSS) and others
 *
 *  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.
 *
 *  Contributors:
 *    Misys Open Source Solutions - initial API and implementation
 *    -
 */

package org.openhealthtools.openxds.webapp.action;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.struts2.ServletActionContext;
import org.openhealthtools.openxds.webapp.control.HttpUtils;

import com.opensymphony.xwork2.ActionSupport;


/**
 * Implementation of <strong>ActionSupport</strong> that contains 
 * convenience methods for subclasses.  For example, getting the current
 * user and saving messages/errors. This class is intended to
 * be a base class for all Action classes.
 * 
 * @author <a href="anilkumar.reddy@misys.com">Anil Kumar</a>
 */
public class BaseAction extends ActionSupport {
    private static final long serialVersionUID = 3525445612504421307L;

    /**
     * Constant for cancel result String
     */
    public static final String CANCEL = "cancel";

    /**
     * Transient log to prevent session synchronization issues - children can use instance for logging.
     */
    protected transient final Log log = LogFactory.getLog(getClass());

   
    protected String cancel;

    /**
     * Indicator for the page the user came from.
     */
    protected String from;

    /**
     * Set to "delete" when a "delete" request parameter is passed in
     */
    protected String delete;

    /**
     * Set to "save" when a "save" request parameter is passed in
     */
    protected String save;

    PrintWriter _writer = null;
	HttpUtils _h = null; 
    /**
     * Simple method that returns "cancel" result
     * @return "cancel"
     */
    public String cancel() {
        return CANCEL;
    }

    /**
     * Save the message in the session, appending if messages already exist
     * @param msg the message to put in the session
     */
    @SuppressWarnings("unchecked")
    protected void saveMessage(String msg) {
        List messages = (List) getRequest().getSession().getAttribute("messages");
        if (messages == null) {
            messages = new ArrayList();
        }
        messages.add(msg);
        getRequest().getSession().setAttribute("messages", messages);
    }


    /**
     * Convenience method to get the request
     * @return current request
     */
    protected HttpServletRequest getRequest() {
        return ServletActionContext.getRequest();
    }

    /**
     * Convenience method to get the response
     * @return current response
     */
    protected HttpServletResponse getResponse() {
        return ServletActionContext.getResponse();
    }

    /**
     * Convenience method to get the session. This will create a session if one doesn't exist.
     * @return the session from the request (request.getSession()).
     */
    protected HttpSession getSession() {
        return getRequest().getSession();
    }

    /**
     * Convenience method for setting a "from" parameter to indicate the previous page.
     * @param from indicator for the originating page
     */
    public void setFrom(String from) {
        this.from = from;
    }

    public void setDelete(String delete) {
        this.delete = delete;
    }

    public void setSave(String save) {
        this.save = save;
    }
    

	protected HttpUtils h() throws ServletException {
		if (_h == null)
			_h = new HttpUtils(get_writer());
		return _h;
	}

	protected void close() {
		if (_h != null) {
			_h.close();
			_h = null;
		}
		_writer = null;
	}

	private PrintWriter get_writer()
	throws ServletException {
		if (_writer == null) {
			try {
				_writer = getResponse().getWriter();
			} catch (IOException e) {
				throw new ServletException("doGet: cannot getWriter()");
			}
		}
		return _writer;
	}

}