mongodb.JavaFindFields.java Source code

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Here is the source code for mongodb.JavaFindFields.java

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/*
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 */
//
//Limiting Which Document Fields Are Returned from Find Requests in Java.

package mongodb;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import java.util.Arrays;

/**
 *
 * @author soham
 */
public class JavaFindFields {
    public static void main(String[] args) {
        try {
            MongoClient mongoClient = new MongoClient("localhost", 27017);
            DB db = mongoClient.getDB("words");
            DBCollection collection = db.getCollection("word_stats");
            JavaFindFields.excludeFields(collection, new String[] {});
            JavaFindFields.includeFields(collection, new String[] { "word" });
            JavaFindFields.includeFields(collection, new String[] { "word", "stats" });
            JavaFindFields.excludeFields(collection, new String[] { "stats", "charsets" });
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    public static void displayCursor(DBCursor cursor) {
        while (cursor.hasNext()) {
            DBObject doc = cursor.next();
            System.out.println(doc);
        }
    }

    public static void includeFields(DBCollection collection, String[] fields) {
        BasicDBObject query = new BasicDBObject("first", "p");
        BasicDBObject fieldDoc = new BasicDBObject();
        for (final String field : fields) {
            fieldDoc.append(field, 1);
        }
        DBCursor cursor = collection.find(query, fieldDoc);
        cursor.limit(1);
        System.out.println("\nIncluding " + Arrays.toString(fields) + " fields: ");
        JavaFindFields.displayCursor(cursor);
    }

    public static void excludeFields(DBCollection collection, String[] fields) {
        BasicDBObject query = new BasicDBObject("first", "p");
        BasicDBObject fieldDoc = new BasicDBObject();
        for (final String field : fields) {
            fieldDoc.append(field, false);
        }
        DBCursor cursor = collection.find(query, fieldDoc);
        cursor.limit(1);
        System.out.println("\nExcluding " + Arrays.toString(fields) + " fields: ");
        JavaFindFields.displayCursor(cursor);
    }
}