ubc.pavlab.aspiredb.server.util.JSONUtil.java Source code

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Here is the source code for ubc.pavlab.aspiredb.server.util.JSONUtil.java

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/*
 * The rdp project
 * 
 * Copyright (c) 2014 University of British Columbia
 * 
 * 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 ubc.pavlab.aspiredb.server.util;

import java.io.StringWriter;
import java.util.Collection;
import java.util.Iterator;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * Commonly used JSON helper functions
 * 
 * @author ptan
 * @version $Id$
 */
public class JSONUtil extends gemma.gsec.util.JSONUtil {

    private static Log log = LogFactory.getLog(JSONUtil.class);

    public JSONUtil(HttpServletRequest request, HttpServletResponse response) {
        super(request, response);
    }

    /**
     * Converts a collection of objects to a json string
     * 
     * @param collection
     * @return
     * @throws JSONException
     */
    public String collectionToJson(Collection<?> collection) throws JSONException {
        StringWriter jsonText = new StringWriter();
        jsonText.write("[");

        try {
            Iterator<?> it = collection.iterator();
            while (it.hasNext()) {
                Object obj = it.next();
                String delim = it.hasNext() ? "," : "";
                jsonText.append(new JSONObject(obj).toString() + delim);
            }
            jsonText.append("]");
            jsonText.flush();
        } catch (Exception e) {
            log.error(e.getLocalizedMessage(), e);
            JSONObject json = new JSONObject();
            json.put("success", false);
            json.put("message", e.getLocalizedMessage());
            jsonText.write(json.toString());
            log.info(jsonText);
        }

        try {
            jsonText.close();
        } catch (Exception e) {
            log.error(e.getLocalizedMessage(), e);
            JSONObject json = new JSONObject();
            json.put("success", false);
            json.put("message", e.getLocalizedMessage());
            jsonText.write(json.toString());
            log.info(jsonText);
        }

        return jsonText.toString();
    }

}