nl.mvdb.mongodb.RemoveStudentsLowestHomeworkScore.java Source code

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Here is the source code for nl.mvdb.mongodb.RemoveStudentsLowestHomeworkScore.java

Source

/*
 * Copyright 2015 MongoDB, Inc.
 *
 * 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 nl.mvdb.mongodb;

import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.ServerAddress;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;

import static com.mongodb.client.model.Sorts.*;
import freemarker.template.Configuration;
import freemarker.template.Template;

import org.bson.Document;

import spark.Request;
import spark.Response;
import spark.Route;
import spark.Spark;

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.swing.SortingFocusTraversalPolicy;

import static java.util.Arrays.asList;

public class RemoveStudentsLowestHomeworkScore {
    public static void main(String[] args) {
        MongoClient client = new MongoClient();
        try {
            MongoDatabase database = client.getDatabase("school");
            MongoCollection<Document> collection = database.getCollection("students");

            MongoCursor<Document> iterator = collection.find().sort(ascending("scores.score")).iterator();

            while (iterator.hasNext()) {
                Document studentDoc = iterator.next();
                System.out.println(studentDoc);

                Document lowestScoreDoc = null;

                List<Document> scoreDocs = (ArrayList) studentDoc.get("scores");
                for (Document scoreDoc : scoreDocs) {
                    if ("homework".equals(scoreDoc.getString("type"))) {
                        Double score = scoreDoc.getDouble("score");
                        if (lowestScoreDoc == null || score < lowestScoreDoc.getDouble("score")) {
                            lowestScoreDoc = scoreDoc;
                        }
                    }
                }

                if (lowestScoreDoc != null) {
                    scoreDocs.remove(lowestScoreDoc);
                    studentDoc.put("scores", scoreDocs);
                    collection.replaceOne(new Document("_id", studentDoc.getInteger("_id")), studentDoc);
                }

            }

            System.out.println(collection.count());
        } finally {
            client.close();
        }
    }
}