de.knurt.fam.template.controller.json.JSONController.java Source code

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Here is the source code for de.knurt.fam.template.controller.json.JSONController.java

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/*
 * Copyright 2009-2012 by KNURT Systeme (http://www.knurt.de)
 *
 * Licensed under the Creative Commons License Attribution-NonCommercial-ShareAlike 3.0 Unported;
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://creativecommons.org/licenses/by-nc-sa/3.0/
 *
 * 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 de.knurt.fam.template.controller.json;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Properties;

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

import org.apache.commons.io.IOUtils;
import org.json.JSONObject;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

/**
 * controller for ajax request to get username.
 * 
 * @author Daniel Oltmanns
 * @since 0.20090311 (03/11/2009)
 */
public abstract class JSONController implements Controller {

    /**
     * print out json with the key and values got from
     * {@link JSONController#getKeyAndValues(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)}
     * 
     * @param rq
     *            request
     * @param rs
     *            response
     * @return null
     */
    @Override
    public ModelAndView handleRequest(HttpServletRequest rq, HttpServletResponse rs) {
        PrintWriter pw = null;
        try {
            rs.setHeader("Content-type", "application/json");
            pw = rs.getWriter();
            IOUtils.write(this.getJSONObject(rq, rs).toString(), pw);
        } catch (IOException ex) {
            this.onException(ex);
        } finally {
            IOUtils.closeQuietly(pw);
        }
        return null;
    }

    /**
     * return {@link Properties} representing json.
     * 
     * @param rq
     *            request
     * @param rs
     *            response
     * @return {@link Properties} representing json.
     */
    public abstract JSONObject getJSONObject(HttpServletRequest rq, HttpServletResponse rs);

    /**
     * handle {@link IOException} if thrown
     * 
     * @param exception
     *            thrown
     */
    public abstract void onException(IOException ex);
}