MongoDB_Java连接Mongo 限制字段返回数

Java连接Mongo 限制字段返回数

数据库中的数据 :



代码:

package com.java.module.mongo.mongo_test_1;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.MongoClient;

import java.net.UnknownHostException;

/**
* Java限制字段返回数
*/
public class JavaFindFields {

public static void main(String[] args) {
try {

MongoClient mongoClient = new MongoClient("localhost", 27017);
DB db = mongoClient.getDB("test");
DBCollection dbCollection = db.getCollection("user");

String[] strArr = new String[]{"name"};
excludeFields(dbCollection, strArr);

} catch (UnknownHostException e) {
e.printStackTrace();
}
}

public static void excludeFields(DBCollection dbCollection, String[] fields) {

BasicDBObject query = new BasicDBObject("age", new BasicDBObject("$lt", 100));
BasicDBObject fieldDoc = new BasicDBObject();

for (int i = 0; i < fields.length; i++) {
String field = fields[i];
fieldDoc.append(field, false);
}

DBCursor dbCursor = dbCollection.find(query,fieldDoc);
while (dbCursor.hasNext()) {
System.out.println(dbCursor.next());
}

}

}