====== Description ======

Spring Data MongoDB도 Spring Data repository 추상화 인터페이스를 지원한다. 이에 대한 내용은 Spring Data JPA 가이드 중 [[egovframework:rte2:psl:data:jpa:repository|Repository]] 부분을 참조한다.

====== 1. 시작하기 ======
MongoDB에 대한 repository를 사용하기 위해서는 다음과 같은 mongo schem의 repistories 설정이 필요하다.

<code xml>
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:mongo="http://www.springframework.org/schema/data/mongo"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
		http://www.springframework.org/schema/data/mongo http://www.springframework.org/schema/data/mongo/spring-mongo.xsd">
		
   <mongo:mongo-client
        host="localhost"        
        port="27017"
        credentials="id:password@database"  >   
    </mongo:mongo-client>
    
    <mongo:db-factory dbname="database" mongo-ref="mongo" />
    
    <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">
        <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" />
    </bean>
	
    <!-- for Repository -->
    <mongo:repositories base-package="egovframework.rte.psl.data.mongodb.repository" />

</beans>
</code>

===== Domain Object 생성 =====
일반적인 POJO를 통해 MongoDB에 문서를 저장한다.

<code java>
public class Person {
	@Id
	private String id;

	private String firstname;

	private String lastname;

	private Address address;
	
	private double[] location;
        
        ...
  
        // getters/setters
</code>

===== 기본 repository interface =====
<code java>
public interface PersonRepository extends MongoRepository<Person, Long> {

  // additional custom finder methods go here
}
</code>

===== Paging 처리 =====
MongoRepository interface는 기본적으로 PagingAndSortingRepository를 extends하기 때문에 다음과 같은 기본 페이징 처리를 지원한다.

<code java>
@Autowired 
private PersonRepository repository;

...

@Test
public void readsFirstPageCorrectly() {

    Page<Person> persons = repository.findAll(new PageRequest(0, 10));
      
    LOGGER.info("Persons Total elements : " + persons.getTotalElements());
      
    assertTrue(persons.isFirst());
}
</code>

====== 2. Query methods ======

Repository는 Spring Data에서 제공되는 keyword 기반의 query method를 사용할 수 있다.

ex:
<code java>
public interface PersonRepository extends MongoRepository<Person, String> {

    List<Person> findByLastname(String lastname);

    Page<Person> findByFirstname(String firstname, Pageable pageable);

    Person findByShippingAddresses(Address address);

}
</code>

지원되는 keyword는 다음과 같다.

^ Keyword ^ Sample ^ Logic result ^
| GreaterThan |findByAgeGreaterThan(int age) |{"age" : {"$gt" : age}} |
| GreaterThanEqual |findByAgeGreaterThanEqual(int age) |{"age" : {"$gte" : age}} |
| LessThan |findByAgeLessThan(int age) |{"age" : {"$lt" : age}} |
| LessThanEqual |findByAgeLessThanEqual(int age) |{"age" : {"$lte" : age}} |
| Between |findByAgeBetween(int from, int to) |{"age" : {"$gt" : from, "$lt" : to}} |
| In |findByAgeIn(Collection ages) |{"age" : {"$in" : [ages...]}} |
| NotIn |findByAgeNotIn(Collection ages) |"age" : {"$nin" : [ages...]}} |
| IsNotNull, NotNull |findByFirstnameNotNull() |{"age" : {"$ne" : null}} |
| IsNull, Null |findByFirstnameNull() |{"age" : null} |
| Like |findByFirstnameLike(String name) |{"age" : age} ( age as regex) |
| Regex |findByFirstnameRegex(String firstname) |{"firstname" : {"$regex" : firstname }} |
| (No keyword) |findByFirstname(String name) |{"age" : name} |
| Not |findByFirstnameNot(String name) |{"age" : {"$ne" : name}} |
| Near |findByLocationNear(Point point) |{"location" : {"$near" : [x,y]}} |
| Within |findByLocationWithin(Circle circle) |{"location" : {"$within" : {"$center" : [ [x, y], distance]}}} |
| Within |findByLocationWithin(Box box) |{"location" : {"$within" : {"$box" : [ [x1, y1], x2, y2]}}} |
| IsTrue, True |findByActiveIsTrue() |{"active" : true} |
| IsFalse, False |findByActiveIsFalse() |{"active" : false} |
| Exists |findByLocationExists(boolean exists) |{"location" : {"$exists" : exists }} |

====== 3. Repository delete queries ======
위의 keyword를 delete..By 또는 remove..By 형태로 사용하는 경우 삭제 처리가 가능하다.

<code java>
public interface PersonRepository extends MongoRepository<Person, String> {
    List <Person> deleteByLastname(String lastname);
  
    Long deletePersonByLastname(String lastname);  		
}
</code>

====== 4. Geo-spatial repository queries ======
Near keyword를 사용하는 경우 geo-spatial 처리와 관련된 query도 처리 가능하다.

<code java>
public interface PersonRepository extends MongoRepository<Person, String>

    // { 'location' : { '$near' : [point.x, point.y], '$maxDistance' : distance}}
    List<Person> findByLocationNear(Point location, Distance distance);
}
</code> 

====== 5. MongoDB JSON based query methods ======
org.springframework.data.mongodb.repository.Query anntation을 사용할 경우 JSON query 방식을 통해 직접 query를 지정할 수 있다.

<code java>
public interface PersonRepository extends MongoRepository<Person, String>

  @Query("{ 'firstname' : ?0 }")
  List<Person> findByThePersonsFirstname(String firstname);

}
</code>