Java 连接MongoDB

package mymaven;

import java.net.UnknownHostException;
import java.util.Set;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoException;

public class Test {
	/**
	 * @author ithomer.net
	 * @datetime 2013-11-11
	 */
	public static void main(String[] args) throws UnknownHostException, MongoException {
		Mongo mongo = new Mongo("172.27.9.104", 27017);		// 连接数据库
		DB db = mongo.getDB("mytestdb");					// 数据库
		Set cols = db.getCollectionNames();			// 获取数据库中所有的集合（类似于获取关系数据库中的表）
		
		// 打印出数据库中的集合，这里应当为null
		for (String s : cols) {
			System.out.println(s);
		}
		
		DBCollection collection = db.getCollection("mytestcoll");		// 创建一个集合
		collection.drop();												// 删除集合，插入数据时自动重建
		BasicDBObject obj = new BasicDBObject();						// 初始化一个基本DB对象，插入数据库的就是DB对象
		
		obj.put("from", "blog.ithomer.net");		// 放入几个键值对
		obj.put("to", "forum.ithomer.net");
		obj.put("subject", "ithomer.net");
		collection.insert(obj);						// 插入对象
		
		DBObject dbobj = collection.findOne();		// 查看一条记录，findOne()=find().limit(1);
		System.out.println(dbobj);					// 打印出刚才插入的数据
		
		// 插入10条{ranking:i}的数据
		for (int i = 0; i < 10; i++) {
			collection.insert(new BasicDBObject().append("ranking", i));
		}
		System.out.println("count: " + collection.getCount());		// 打印集合中的数据总数

		
		DBCursor cursor = collection.find();		// 然后我们使用这个游标来遍历集合
		while (cursor.hasNext()) {
			System.out.println(cursor.next());
		}
		// 简单的条件查询，查询ranking为1的记录
		BasicDBObject query = new BasicDBObject();
		query.put("ranking", 1);
		cursor = collection.find(query);
		System.out.println("collection find({\"ranking\":1}):");
		while (cursor.hasNext()) {
			System.out.println(cursor.next());
		}
		
		// 复杂的条件查询，查询ranking大于等于5小于9的记录
		query = new BasicDBObject();
		query.put("ranking", new BasicDBObject("$gte", 5).append("$lt", 9));
		cursor = collection.find(query);
		System.out.println("collection find({\"ranking\":[5-9)}):");
		while (cursor.hasNext()) {
			System.out.println(cursor.next());
		}
		
//		mongo.dropDatabase("mytestdb");			// 最后删除我们的测试数据库
	}
}

运行结果：

mytestcoll
system.indexes
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10107"} , "from" : "blog.ithomer.net" , "to" : "forum.ithomer.net" , "subject" : "ithomer.net"}
count: 11
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10107"} , "from" : "blog.ithomer.net" , "to" : "forum.ithomer.net" , "subject" : "ithomer.net"}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10108"} , "ranking" : 0}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10109"} , "ranking" : 1}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010a"} , "ranking" : 2}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010b"} , "ranking" : 3}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010c"} , "ranking" : 4}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010d"} , "ranking" : 5}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010e"} , "ranking" : 6}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010f"} , "ranking" : 7}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10110"} , "ranking" : 8}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10111"} , "ranking" : 9}
collection find({"ranking":1}):
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10109"} , "ranking" : 1}
collection find({"ranking":[5-9)}):
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010d"} , "ranking" : 5}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010e"} , "ranking" : 6}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd1010f"} , "ranking" : 7}
{ "_id" : { "$oid" : "52c62ed8e4b0f4de3dd10110"} , "ranking" : 8}

源码下载（maven）

mongodb数组示例：