exp_blog

1. MongoDB와 JAVA 연동

- mongod 인스턴스 및 데이터베이스 연결

// import된 각 패키지들에 대한 설명은 API 문서 참조
import com.mongodb.client.MongoDatabase;
import com.mongodb.MongoClient;
public class ConnectToDB {
   public static void main( String args[] ) {

   // Creating a Mongo client
   MongoClient myclient = new MongoClient("localhost" , 27017);

   // 또는 MongoClient myclient = new MongoClient();
   System.out.println("Connected to the database successfully");

   // Accessing the database (db가 없으면 새로 생성)
   MongoDatabase mydb = myclient.getDatabase("sdb");
  }
}

- 컬렉션 생성

import com.mongodb.client.MongoDatabase;
import com.mongodb.MongoClient;
public class ConnectToDB {
   public static void main( String args[] ) {
   
   // Creating a Mongo client
   MongoClient myclient = new MongoClient();
   System.out.println("Connected to the database successfully");
   
   // Accessing the database
   MongoDatabase mydb = myclient.getDatabase("sdb");
   
   //Creating a collection
   mydb.createCollection("sampleCol");
   System.out.println("Collection created successfully");
  }
}

- 특정 DB 내의 모든 컬렉션 이름 출력

import com.mongodb.client.MongoDatabase;
import com.mongodb.MongoClient;
. . .
public class ListOfCollection {
 public static void main( String args[] ) {
 . . .

 // Accessing the database
 MongoDatabase mydb = myclient.getDatabase("sdb");
 
 // listing all collections
   for (String name : mydb.listCollectionNames()) {
   System.out.println(name);
   }
 }
}

- 컬렉션 선택(반환)

import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.MongoClient;
import org.bson.Document;
public class selectingCollection {
  public static void main( String args[] ) {
   . . .

   // Accessing the database
   MongoDatabase mydb = myclient.getDatabase("sdb");

   // Retrieving a collection
   MongoCollection<Document> mycol = mydb.getCollection("sampleCol");
   System.out.println("Collection Col selected successfully");
  }
}

-컬렉션 제거(drop)

import com.mongodb.client.MongoCollection;
. . .
public class DroppingCollection {
 public static void main( String args[] ) {
 . . .
 // Accessing the database
 MongoDatabase mydb = myclient.getDatabase("sdb");
 
 // Retrieving a collection
 MongoCollection<Document> mycol = mydb.getCollection("sampleCol");
 
 // Dropping a Collection
 mycol.drop();
 System.out.println("Collection dropped successfully");
 }
}

- document삽입

. . .
import org.bson.Document;
public class insertingDocument {
 public static void main( String args[] ) {
 . . .
 // Retieving a collection
 MongoCollection<Document> mycol = mydb.getCollection("sampleCol");
 System.out.println("Collection Col selected successfully");
 
 // bson Document 객체 생성
 Document mydoc = new Document("title", "MongoDB")
 .append("id", 1)
 .append("description", "database")
 .append("likes", 100)
 .append("url", "http://www.tutorialspoint.com/mongodb/")
 .append("by", "tutorials point");
 mycol.insertOne(mydoc);
 System.out.println("Document inserted successfully");
 }
}

-컬렉션 내 모든 문서 검색

import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import java.util.Iterator;
. . .
public class RetrievingAllDocuments {
 public static void main( String args[] ) {
 . . .
 // Retrieving a collection
 MongoCollection<Document> mycol = mydb.getCollection("sampleCol");

 // Getting the iterable object
 FindIterable<Document> iterDoc = mycol.find();
 
 // Getting the iterator
 Iterator it = iterDoc.iterator(); // iterator 반환
 int i = 1;
   while (it.hasNext()) {
   System.out.println(it.next());
   i++;
   }
 }
}

-document 수정

import com.mongodb.client.MongoCollection;
import com.mongodb.client.FindIterable;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.Updates;
. . .
public class UpdatingDocuments {
 public static void main( String args[] ) {
 . . .
 // Updating a document
 mycol.updateOne(Filters.eq("id", 1), Updates.set("likes", 150));
 System.out.println("Document update successfully...");
 
 // Getting the iterable object
 FindIterable<Document> iterDoc = mycol.find();
 
 // Getting the iterator
 Iterator it = iterDoc.iterator(); // iterator 반환
 int i = 1;
   while (it.hasNext()) {
   System.out.println(it.next()); i++;
   }
 }
}

- document 삭제

import com.mongodb.client.MongoCollection;
import com.mongodb.client.FindIterable;
import com.mongodb.client.model.Filters;
. . .
public class DeletingDocuments {
 public static void main( String args[] ) {
 . . .
 // Deleting a document
 mycol.deleteOne(Filters.eq("id", 1)); // deleteMany() 메소드
 System.out.println("Document deleted successfully...");
 
 // Getting the iterable object
 FindIterable<Document> iterDoc = mycol.find();
 int i = 1;
 
 // Getting the iterator
 Iterator it = iterDoc.iterator(); // iterator 반환
   while (it.hasNext()) {
   System.out.println(it.next()); i++;
   }
 }
}

-조건에 맞는 특성 문서 검색

import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import java.util.Iterator;
. . .
public class RetrievingAllDocuments {
 public static void main( String args[] ) {
 . . .
 // Retrieving a collection
 MongoCollection<Document> mycol = mydb.getCollection("sampleCol");

 // Finding a document with find(Bson filter) method
 // and Getting the iterable object
 FindIterable<Document> iterDoc = mycol.find(검색조건); // 커서 반환
 //검색 조건 : find() / delete() / update()  조건 표현은 동일 
 //각종 메소드 활용 가능 
 . . .
 }
}

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자바 연동 과제는 따로 보관 ㅎㅎ