Java Code for mongoDB Query

Java Code for mongoDB Query

1. MongoCursor 생성

Document docQuery = new Document(); docQuery.put("key1","value1"); MongoCursor<Document> mc = collection.find(docQuery).iterator(); Document curDoc = mc.next; ... mc.close(); // cursor close

2. MongoClient 생성

List<MongoCredential> credentialList = new ArrayList<>(); MongoCredential credential = MongoCredential.createCredential(_USER, "admin",_PWD.toCharArray() ); credentialList.add(credential); ServerAddress svr = new ServerAddress(_SVR, _PORT); mongoClient = new MongoClient(svr, credentialList); ... mongoClient.close(); // 연결 닫기

3. MongoCollection 생성

MongoDatabase db = mongoClient.getDatabase(dbName); MongoCollection<Document> collection = db.getColleciton(collectionName);

* ISODate, docQuery, 자료 목록 가져오기

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); Date gtDate = sdf.parse("2018-06-04T00:00:00.000Z"); Document docQuery = new Document(); docQuery.put("reg_dt", new Document("$gt", gtDate) );

* ISODate, JSON -> Document, 자료 추가 하기

String jsonData = "{"          + " 'key1' : '"+ curDoc.get("key1")+"',"+         + " 'key2' : '"+ curDoc.get("key2")+"'"+ "}"; Document docInsert = Document.parse(jsonData); docInsert("reg_dt", regDate); collection.insertOne(docInsert);

* Error 1,  메시지 & 해결 시도 방법

Q	A pipeline stage specification object must contain exactly one field.
A	You should make a pair every pipeline in {}. db.collection.aggregation(   { $group: ... },   { $match: ...} )