java操作mongodb实例

package mongodb;import java.net.UnknownHostException;import com.mongodb.BasicDBObject;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.Mongo;import com.mongodb.MongoException;/** * Java + MongoDB Hello world Example *  */public class MongoDb {public static void main(String[] args) {try {// 实例化Mongo对象，连接27017端口Mongo mongo = new Mongo("localhost", 27017);// 连接名为xiaodb的数据库，假如数据库不存在的话，mongodb会自动建立DB db = mongo.getDB("xiaodb");// Get collection from MongoDB, database named "xiao"// 从Mongodb中获得名为users的数据集合，如果该数据集合不存在，Mongodb会为其新建立DBCollection collection = db.getCollection("users");// 使用BasicDBObject对象创建一个mongodb的document,并给予赋值。BasicDBObject document = new BasicDBObject();document.put("id", 1001);document.put("msg", "hello world mongoDB in Java");// 将新建立的document保存到collection中去collection.insert(document);// 创建要查询的documentBasicDBObject searchQuery = new BasicDBObject();searchQuery.put("id", 1002);// 使用collection的find方法查找documentDBCursor cursor = collection.find(searchQuery);// 循环输出结果while (cursor.hasNext()) {System.out.println(cursor.next());}System.out.println("Done");} catch (UnknownHostException e) {e.printStackTrace();} catch (MongoException e) {e.printStackTrace();}}}