mongodb.JavaFindDistinct.java Source code

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Here is the source code for mongodb.JavaFindDistinct.java

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/*
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//Retrieving Distinct Values for a Specific Field Using Java.
//To demostrate ways to generate list of distinct field values in datasets from java applications.
package mongodb;

/**
 *
 * @author soham
 */
import com.mongodb.MongoClient;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.BasicDBObject;
import java.util.List;

public class JavaFindDistinct {
    public static void main(String[] args) {
        try {
            MongoClient mongoClient = new MongoClient("localhost", 27017);
            DB db = mongoClient.getDB("words");
            DBCollection collection = db.getCollection("word_stats");
            JavaFindDistinct.sizesOfAllWords(collection);
            JavaFindDistinct.sizesOfQWords(collection);
            JavaFindDistinct.firstLetterOfLongWords(collection);
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    public static void sizesOfAllWords(DBCollection collection) {
        List<Double> results = collection.distinct("size");
        System.out.println("\nDistinct Sizes of words: ");
        System.out.println(results.toString());
    }

    public static void sizesOfQWords(DBCollection collection) {
        BasicDBObject query = new BasicDBObject("first", "q");
        List<Double> results = collection.distinct("size", query);
        System.out.println("\nDistinct Sizes of words starting with Q: ");
        System.out.println(results.toString());
    }

    public static void firstLetterOfLongWords(DBCollection collection) {
        BasicDBObject query = new BasicDBObject("size", new BasicDBObject("$gt", 12));
        List<String> results = collection.distinct("first", query);
        System.out.println("\nDistinct first letters of words longer " + "than  12 characters: ");
        System.out.println(results.toString());
    }
}