#Querydsl #Spring

PREDICATOR

git source 링크

kotlin_version 링크

PREDICATOR가 왜필요할지는 동적쿼리를 매번매번 function으로 추가하여 쓸데없는 메소드 추가를 방지

바로 소스 카즈아

중요부분 매우 중요

괜히 이펙티브자바에서 빌더를 써라라고 하는것이 아님!

UserPredicator.java

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package com.beanbroker.sample.api.user.service;

import com.beanbroker.sample.api.user.entity.QUserEntity;
import com.querydsl.core.BooleanBuilder;
import com.querydsl.core.types.Predicate;
import org.springframework.util.StringUtils;

public class UserPredicator {

    private static final QUserEntity table = QUserEntity.userEntity;

    private BooleanBuilder builder = new BooleanBuilder();


    public UserPredicator userId(String userId){

        if(userId != null){
            builder.and(table.userId.eq(userId));
        }
        return this;
    }

    public UserPredicator name(String name){

        if(name != null){
            builder.and(table.name.eq(name));
        }
        return this;
    }

    public UserPredicator age(int age){

        if(age > 0){
            builder.and(table.age.eq(age));
        }
        return this;
    }

    public Predicate values(){

        return builder.getValue();
    }
}

참쉬죠잉?

UserRepositoryCustom.java

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import com.beanbroker.sample.api.user.entity.UserEntity;
import com.querydsl.core.types.Predicate;
public interface UserRepositoryCustom {


    UserEntity getByUserId(String userId);
    UserEntity getUserInfoWithPredicator(Predicate predicate);
}

UserRepositoryImpl.java

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public class UserRepositoryImpl extends QuerydslRepositorySupport
        implements UserRepositoryCustom {

    private static final QUserEntity table = QUserEntity.userEntity;


    /**
     * Creates a new {@link QuerydslRepositorySupport} instance for the given domain type.
     *
     * @param domainClass must not be {@literal null}.
     */
    public UserRepositoryImpl() {
        super(UserEntity.class);
    }

    @Override
    public UserEntity getByUserId(String userId) {

        return  from(table)
                .where(table.userId.eq(userId))
                .fetchOne();

    }

    @Override
    public UserEntity getUserInfoWithPredicator(Predicate userPredicator) {
        return from(table)
                .where(userPredicator)
                .fetchOne();
    }
}

셋팅은 끝낫는데 how to use?

아래가 핵심코드

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public UserEntity getUserInfoWithPredicator(
           String userId,
           String name,
           int age

   ){



       return userRepository.getUserInfoWithPredicator(
               setUserQuery(userId, name, age)
       );
   }


   private Predicate setUserQuery( String userId,
                                   String name,
                                   int age){

       return new UserPredicator()
               .userId(userId)
               .name(name)
               .age(age)
               .values();

   }

그럼 써보자

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UserEntity test1 = userService.getUserInfoWithPredicator(
             "beanbroker",
             null,
             0

     );

     System.out.println(test1.toString());


     UserEntity test2 = userService.getUserInfoWithPredicator(
             "beanbroker",
                 "pkj",
             0

     );


     System.out.println(test2.toString());

     UserEntity test3 = userService.getUserInfoWithPredicator(
             null,
             null,
             32

     );

     System.out.println(test3.toString());

아 요즘은 왜 저렇게써야하는지 설명 적는게 귀찮다…. 활용방법은 다양하니! 잘사용합시당

#Querydsl #Spring