（1）数据库准备

mongoDB数据库、表、记录等创建好

（2）jar包准备

要下载MongoDB的jar包，例如 mongo-java-driver-3.2.2.jar

2.编写Java代码

（1）基本思路

连接服务器、连接数据库、连接表、创建迭代器、创建游标、滚动游标、读取记录、读取字段值

（2）代码

<span style="font-size: 18px;"><span style="color: #000000;">package com.gs;
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
public class HelloMongodb
{
    public static </span><span style="color: #0000ff;">void</span><span style="color: #000000;"> main(String[] args)
    {
        </span><span style="color: #0000ff;">try</span><span style="color: #000000;">
        {
            </span><span style="color: #008000;">/*</span><span style="color: #008000;">
             * MongoClient               连接服务器
             * MongoDatabase             连接数据库
             * MongoCollection           连接表
             * FindIterable<Document>    记录型迭代器
             * MongoCursor               记录游标
             * 应用顺序： 服务器-->数据库-->表-->记录迭代器-->记录游标
             </span><span style="color: #008000;">*/</span><span style="color: #000000;">
            MongoClient mongoClient </span>= <span style="color: #0000ff;">new</span> MongoClient("localhost", 27017<span style="color: #000000;">);            
            MongoDatabase mongoDatabase </span>= mongoClient.getDatabase("mywork"<span style="color: #000000;">);            
            MongoCollection</span><Document> collection = mongoDatabase.getCollection("student"<span style="color: #000000;">);
            FindIterable</span><Document> findIterable =<span style="color: #000000;"> collection.find();  
            MongoCursor</span><Document> mongoCursor =<span style="color: #000000;"> findIterable.iterator();  
            
            </span><span style="color: #008000;">/*</span><span style="color: #008000;">
             * 游标滚动-->获取记录-->读取字段值         
             </span><span style="color: #008000;">*/</span>
            <span style="color: #0000ff;">while</span><span style="color: #000000;">(mongoCursor.hasNext()){  
                Document studentDocument </span>=<span style="color: #000000;"> mongoCursor.next();
                System.out.println(studentDocument.getString(</span>"name") +", "<span style="color: #000000;"> );
                </span><span style="color: #008000;">//</span><span style="color: #008000;">System.out.println(mongoCursor.next());  </span>
<span style="color: #000000;">             }  
        }
        </span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (Exception e)
        {
            System.err.println(e.getMessage());
        }
        
    }
}</span></span>

Java读取MongoDB数据库值

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