Question

如何用java操作mongodb

Answer 1

public class MongoDBJDBC {
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yourdb的数据库，假如数据库不存在的话，mongodb会自动建立
DB db = mongo.getDB("test");
// Get collection from MongoDB, database named "yourDB"
// 从Mongodb中获得名为yourColleection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("test1");
// 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document
BasicDBObject searchQuery = new BasicDBObject();
searchQuery.put("name", "chen");
// 使用collection的find方法查找document
DBCursor cursor = collection.find(searchQuery);
// 循环输出结果
while (cursor.hasNext()) {
System.out.println(cursor.next());
}
System.out.println("Hello World");
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (MongoException e) {
e.printStackTrace();
}
}
}

Answer 2

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 mongo {

/**
* @param args
*/
@SuppressWarnings("rawtypes")
public static void main(String[] args) {
// TODO Auto-generated method stub

//连接mongoDB
MongoClient mongoClient = new MongoClient("localhost", 27017);
//获取数据库
MongoDatabase db = mongoClient.getDatabase("db");
//获取数据库中的集合
MongoCollection users = db.getCollection("db");
//查询结果
FindIterable f = users.find();
MongoCursor cur = f.iterator();
//取出结果
while(cur.hasNext()){
Document doc = (Document) cur.next();
System.out.println("---------------------------------------------------------------------------------");
System.out.println(doc.toJson());
System.out.println(doc.get("_id"));
doc.clear();
}
cur.close();
mongoClient.close();
}

}