MongoDBJava连接
程序员文章站
2022-05-31 22:41:55
...
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 Setcols = 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(ListmediaEntityList) { 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()
上一篇: JAVA中定时器的使用