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MongoDBJava连接

程序员文章站 2022-05-31 22:41:55
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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;impor

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 

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:

	@SuppressWarnings("unchecked")
	public static void loadMediaTags(List mediaEntityList) {
		mediaEntityList.clear();
		
		try {
			Mongo mongo = new Mongo(CosineCluster.gMongo_HOST, CosineCluster.gMongo_PORT);
			DB db = mongo.getDB(CosineCluster.gMongo_DB);
			DBCollection collection = db.getCollection(CosineCluster.gMongo_Coll_Media);
			
			DBCursor cursor = collection.find();
			int index = 0;
			long startTime = System.currentTimeMillis();
			while(cursor.hasNext()){
				BasicDBObject obj = (BasicDBObject) cursor.next();
				
				long id = obj.getLong("_id");
				ArrayList tagList = (ArrayList) obj.get("tag");					// tag
				ArrayList keywordList = (ArrayList)obj.get("keyword");			// keyword
				ArrayList copyrightList = (ArrayList)obj.get("copyright");	// copyright
				
		
				MediaEntity mediaEntity = new MediaEntity();
				
				mediaEntity.setId(id);
				
				// tag
				for(int j=0; j actorsObjList = (ArrayList)obj.get("actors");		// actors
				for(int j=0; j directorObjList = (ArrayList)obj.get("director");	// director
				for(int j=0; j 100) {
					break;
				}
				System.out.println(index + " --- mediaEntity : " + mediaEntity.toString());
			}
			long costTime = System.currentTimeMillis() - startTime;
			System.out.println("load data costTime = " + index + "; costTime = " + costTime/1000f);
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public static int getTagInt(String tag) {
		int tagIntId = -1;
		
		try {
			MongoClient mongo = new MongoClient(CosineCluster.gMongo_HOST, CosineCluster.gMongo_PORT);
			DB db = mongo.getDB(CosineCluster.gMongo_DB);
			DBCollection tagmapCollection = db.getCollection("recommend_tag_map");

			DBCursor cursor = tagmapCollection.find(new BasicDBObject("name", tag));	
			if(cursor == null || cursor.toArray().size()