com.thaonedroid.mongodbexercise.MongoDB.java Source code

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Here is the source code for com.thaonedroid.mongodbexercise.MongoDB.java

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/*
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package com.thaonedroid.mongodbexercise;

import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Scanner;
import org.bson.Document;

/**
 *
 * @author thatOneDroid
 */
public class MongoDB {

    static Query query = new Query();
    final static String q1 = "1. How many Twitter users are in our database?";
    final static String q2 = "2. Which Twitter users link the most to other Twitter users?";
    final static String q3 = "3. Who is are the most mentioned Twitter users?";
    final static String q4 = "4. Who are the most active Twitter users? (Top 10)";
    final static String q5 = "5. Who are the five most grumpy users?";
    final static String q6 = "6. Who are the five most happy users?";

    public static void main(String[] args) {
        try {
            MongoClientURI connStr = new MongoClientURI("mongodb://localhost:27017");
            MongoClient mongoClient = new MongoClient(connStr);

            MongoDatabase db = mongoClient.getDatabase("twitter");
            MongoCollection<Document> collection = db.getCollection("tweets");

            Scanner scanner = new Scanner(System.in);
            int input;
            OUTER: do {
                start();
                input = scanner.nextInt();
                switch (input) {
                case 1:
                    //System.out.println("Distinct Twitter users : " + query.totalUsers());
                    System.out.println("Question : " + q1);
                    execute(query.totalUsers());
                    break;
                case 2:
                    //execute(query.linkOthers());
                    System.out.println("Question : " + q2);
                    System.out.println("Answer : Query hasn't been properly figured out yet");
                    break;
                case 3:
                    //execute(query.mostMentioned());
                    System.out.println("Question : " + q3);
                    System.out.println("Answer : Query hasn't been properly figured out yet");
                    break;
                case 4:
                    System.out.println("Question : " + q4);
                    execute(query.mostActive());
                    //System.out.println("Most active users : " + query.mostActive());
                    break;
                case 5:
                    System.out.println("Question : " + q5);
                    execute(query.mostGrumpy());
                    //System.out.println("Most grumpy users : " + query.mostGrumpy());
                    break;
                case 6:
                    System.out.println("Question : " + q6);
                    execute(query.mostHappy());
                    //System.out.println("Most happy users : " + query.mostHappy());
                    break;
                case 7:
                    break OUTER;
                default:
                    break;
                }
            } while (true);
            mongoClient.close();
        } catch (Exception e) {
            System.err.println(e.getClass().getName() + ":" + e.getMessage());
        }
    }

    private static void start() {

        System.out.println("");
        System.out.println("Welcome to the Twitter database.");
        System.out.println("");
        System.out.println("Input a number for the corresponding question to be answered.");
        System.out.println("");
        System.out.println(q1);
        System.out.println(q2);
        System.out.println(q3);
        System.out.println(q4);
        System.out.println(q5);
        System.out.println(q6);
        System.out.println("7. End program.");
    }

    public static void execute(String q) {
        // implement the logic
        Runtime rt = Runtime.getRuntime();
        try {

            String db = "twitter";

            // run a command from terminal. this line is equivalent to
            // mongo database --eval "db.col.find()"
            // it calls the mongo binary and execute the javascript you
            // passed in eval parameter. It should work for both unix and
            // windows
            Process pr = rt.exec(new String[] { "mongo", db, "--eval", q });
            // read the output of the command
            InputStream in = pr.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            StringBuilder out = new StringBuilder();
            String line;
            int countLines = 1;
            while ((line = reader.readLine()) != null) {
                if (countLines > 2) {
                    out.append("\n" + line);
                }
                countLines++;
            }

            // print the command and close outputstream reader
            System.out.println("");
            System.out.println("-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-");
            System.out.println("Answer : " + out.toString());
            System.out.println("-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-");
            //1 System.out.println(out.toString());
            reader.close();
        } catch (IOException ex) {
            System.out.println(ex);
        }
    }
}