下載mongoDB的java驅動包  https://mongodb.github.io/mongo-java-driver/

查詢資料庫中的文件：

//連線資料庫服務

Mongo mongo = new Mongo("localhost",27017);

//連線資料庫
DB db = mongo.getDB("test");

//查詢集合
DBCollection collection = db.getCollection("customer");

//遍歷文件
DBCursor dbCursor = collection.find();
System.out.println(collection.getCount());
while(dbCursor.hasNext()){
System.out.println(dbCursor.next());
}

//關閉連線
mongo.close();

刪除集合中的文件：
Mongo mongo = new Mongo("localhost",27017);
DB db = mongo.getDB("test");
DBCollection collection = db.getCollection("customer");
BasicDBObject o = new BasicDBObject("_id", new ObjectId("5199ee647d5fc789bc760c07"));
collection.remove(o);
mongo.close();

向集合中插入文件：
Mongo mongo = new Mongo("localhost",27017);
DB db = mongo.getDB("test");
DBCollection collection = db.getCollection("customer");
DBObject c = new BasicDBObject();
c.put("name","jack");
c.put("age",24);
collection.insert(c);
mongo.close();

更新集合中的文件:

//連線資料庫服務
Mongo mongo = new Mongo("localhost",27017);

//連線資料庫
DB db = mongo.getDB("test");

//查詢集合
DBCollection person = db.getCollection("person");

//建立id物件
BasicDBObject query = new BasicDBObject("_id",new ObjectId("51b2eff29f7c0d9e8a511fb4"));

//根據id查詢集合資料
DBObject one = person.findOne(query);

//修改資料
one.put("name", "wangwu");

//更新資料庫資訊
WriteResult update = person.update(query, one);

//列印返回引數
System.out.println(update.getN());

//關閉連線
mongo.close();