AJAXAction.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.struts;

import com.liferay.portal.kernel.servlet.HttpHeaders;
import com.liferay.portal.kernel.util.ContentTypes;
import com.liferay.portal.kernel.util.PortalUtil;

import java.io.PrintWriter;

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

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

/**
 * @author Brian Wing Shun Chan
 */
public abstract class AJAXAction extends Action {

	@Override
	public ActionForward execute(
			ActionMapping actionMapping, ActionForm actionForm,
			HttpServletRequest request, HttpServletResponse response)
		throws Exception {

		String text = null;

		try {
			text = getText(actionMapping, actionForm, request, response);
		}
		catch (Exception e) {
			PortalUtil.sendError(
				HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e, request,
				response);

			return null;
		}

		response.setContentType(ContentTypes.TEXT_PLAIN_UTF8);
		response.setHeader(
			HttpHeaders.CACHE_CONTROL,
			HttpHeaders.CACHE_CONTROL_NO_CACHE_VALUE);

		try (PrintWriter printWriter = response.getWriter()) {
			printWriter.write(text);
		}

		return null;
	}

	public abstract String getText(
			ActionMapping actionMapping, ActionForm actionForm,
			HttpServletRequest request, HttpServletResponse response)
		throws Exception;

}