[JPA] QueryDsl 1-2. Querydsl 설정과 검증

build.gradle 에 주석을 참고해서 querydsl 설정 추가

plugins {
	id 'java'
	id 'org.springframework.boot' version '2.7.17'
	id 'io.spring.dependency-management' version '1.0.15.RELEASE'

}

group = 'study'
version = '0.0.1-SNAPSHOT'

java {
	sourceCompatibility = '11'
}

configurations {
	compileOnly {
		extendsFrom annotationProcessor
	}
}

repositories {
	mavenCentral()
}

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
	implementation 'org.springframework.boot:spring-boot-starter-web'

	//Querydsl 추가
	implementation 'com.querydsl:querydsl-jpa'
	annotationProcessor "com.querydsl:querydsl-apt:${dependencyManagement.importedProperties['querydsl.version']}:jpa"
	annotationProcessor "jakarta.annotation:jakarta.annotation-api"
	annotationProcessor "jakarta.persistence:jakarta.persistence-api"

	compileOnly 'org.projectlombok:lombok'
	runtimeOnly 'com.h2database:h2'
	annotationProcessor 'org.projectlombok:lombok'
	testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

tasks.named('test') {
	useJUnitPlatform()
}


//Querydsl 추가, 자동 생성된 Q클래스 gradle clean으로 제거
clean {
	delete file('src/main/generated')
}

검증용 엔티티 생성

package study.querydsl.entity;

import lombok.Getter;
import lombok.Setter;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
@Getter @Setter
public class Hello {

    @Id @GeneratedValue
    private Long id;
}

참고: Q타입은 컴파일 시점에 자동 생성되므로 버전관리(GIT)에 포함하지 않는 것이 좋다.

테스트 케이스로 실행 검증

package study.querydsl;

import com.querydsl.jpa.impl.JPAQueryFactory;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.transaction.annotation.Transactional;
import study.querydsl.entity.Hello;
import study.querydsl.entity.QHello;

import javax.persistence.EntityManager;

import static org.assertj.core.api.Assertions.*;

@SpringBootTest
@Transactional
class QuerydslApplicationTests {

	@Autowired
	EntityManager em;

	@Test
	void contextLoads() {
		Hello hello = new Hello();
		em.persist(hello);

		JPAQueryFactory query = new JPAQueryFactory(em);
		QHello qHello = QHello.hello;

		Hello result = query
				.selectFrom(qHello)
				.fetchOne();

		assertThat(result).isEqualTo(hello);
		assertThat(result.getId()).isEqualTo(hello.getId());
	}

}