com.hangum.tadpole.mongodb.core.test.MongoTestMapReduce.java Source code

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Here is the source code for com.hangum.tadpole.mongodb.core.test.MongoTestMapReduce.java

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/*******************************************************************************
 * Copyright (c) 2013 hangum.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *     hangum - initial API and implementation
 ******************************************************************************/
package com.hangum.tadpole.mongodb.core.test;

import java.util.Map;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.MapReduceCommand;
import com.mongodb.MapReduceOutput;
import com.mongodb.Mongo;

/**
 * MongoDB MapReduce example
 * 
 * 
 // map
function() {
 emit(this.name, {count: 1, sum: this.number});
};
    
 // reduce
 function(key,values) {
var n = { count: 0, sum: 0};
for ( var i = 0; i < values.length; i ++ ) {
    n.sum += values[i].sum;
    n.count += values[i].count;
};
    
return n;
};
    
 * 
 * 
 * @author hangum
 * 
 */
public class MongoTestMapReduce {

    static String map = "function(){emit(this.name, {count: 1, sum: this.number});};";

    static String reduce = "function( key , values ){" + "var n = { count: 0, sum: 0}; "
            + "for ( var i = 0; i < values.length; i ++ ) {" + "n.sum += values[i].sum;"
            + "n.count += values[i].count;" + "};" +

            "return n;" + "};";

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {

        ConAndAuthentication testMongoCls = new ConAndAuthentication();
        Mongo mongo = testMongoCls.connection(ConAndAuthentication.serverurl, ConAndAuthentication.port);
        DB db = mongo.getDB("test");
        DBCollection coll = db.getCollection("person");

        MapReduceOutput out = coll.mapReduce(map, reduce, null, MapReduceCommand.OutputType.INLINE, null);
        for (DBObject obj : out.results()) {
            System.out.println("======================================================");
            System.out.println("\t[_id]\t" + obj.get("_id"));
            Map objResult = (Map) obj.get("value");
            System.out.println("\t[count]\t" + objResult.get("count"));
            System.out.println("\t[sum]\t" + objResult.get("sum"));

            System.out.println(obj);
        }
        out.getRaw();
        out.getRaw();

        mongo.close();

        try {
            Thread.sleep(1);
        } catch (Exception e) {
        }
    }
}