Basics of java operation mongodb (query, sort, output list)
package com.infomorrow.webroot; import java.util.List; import com.mongodb.BasicDBObject; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.MongoClient; public class test_mongodb { public static void main(String args[]) throws Exception { MongoClient mongoClient = new MongoClient( "127.0.0.1" , 27017 );//建立连接 DB get_db_credit = mongoClient.getDB("credit_2");//数据库名 DBCollection collection = get_db_credit.getCollection("report");//集合名,对应mysql中的表名 BasicDBObject filter_dbobject = new BasicDBObject(); //建立查询条件,如果还有其他条件,类似的写即可 // 如:version=3,filter_dbobject.put("version", 3),mongod区分String 和 Integer类型,所以要小心"3"!=3 filter_dbobject.put("user_id", "10065716153075"); //下面执行查询,设置limit,只要10条数据,排序(类mysql orderby) 再建一个BasicDBObject即可,-1表示倒序 DBCursor cursor = collection.find(filter_dbobject).limit(10).sort(new BasicDBObject("create_time",-1)); //把结果集输出成list类型 List<DBObject> list = cursor.toArray(); System.out.println(list.size());//list的长度 System.err.println(cursor.count());//计算结果的数量,类似于(mysql count()函数),不受limit的影响 //遍历结果集 while(cursor.hasNext()) { System.out.println(cursor.next()); } } }
For more java operation mongodb basics (query, sort, output list) related articles, please pay attention to the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



Field mapping processing in system docking often encounters a difficult problem when performing system docking: how to effectively map the interface fields of system A...

When using MyBatis-Plus or other ORM frameworks for database operations, it is often necessary to construct query conditions based on the attribute name of the entity class. If you manually every time...

Analysis of memory leak phenomenon of Java programs on different architecture CPUs. This article will discuss a case where a Java program exhibits different memory behaviors on ARM and x86 architecture CPUs...

Start Spring using IntelliJIDEAUltimate version...

Troubleshooting and solutions to the company's security software that causes some applications to not function properly. Many companies will deploy security software in order to ensure internal network security. ...

Discussing the hierarchical architecture problem in back-end development. In back-end development, common hierarchical architectures include controller, service and dao...

Questions and Answers about constant acquisition in Java Remote Debugging When using Java for remote debugging, many developers may encounter some difficult phenomena. It...

How to convert names to numbers to implement sorting within groups? When sorting users in groups, it is often necessary to convert the user's name into numbers so that it can be different...
