springframework JPA + QueryDSL

JPA는 쿼리가 너무 정적이라는 단점이 존재합니다. 이러한 단점을 극복하기 위하여 JAP+QueryDSL을 통해 type-safe하고, 자바의 메소드를 통한 동적인(유연한) 쿼리 작성이 가능해집니다.

이전 글에서 JPA사용법에 대하여 간단히 작성했지만 이번 글에서도 JPA부터 설명하겠습니다.

pom.xml 설정

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JPA 및 querydsl 등 각종 dependency 설정입니다.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.spring</groupId>
    <artifactId>jpa</artifactId>
    <name>springjpa</name>
    <packaging>war</packaging>
    <version>1.0.0-BUILD-SNAPSHOT</version>
    <properties>
        <java-version>1.8</java-version>
        <org.springframework-version>5.0.2.RELEASE</org.springframework-version>
        <org.aspectj-version>1.6.10</org.aspectj-version>
        <org.slf4j-version>1.6.6</org.slf4j-version>
        <!--querydsl version 명시-->
        <querydsl.version>4.1.4</querydsl.version>
    </properties>
    <!-- 오라클 저장소 -->
    <repositories>
        <repository>
            <id>codelds</id>
            <url>https://code.lds.org/nexus/content/groups/main-repo</url>
        </repository>
    </repositories>
    <dependencies>
        <!--querydsl dependency-->
        <dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-apt</artifactId>
            <version>${querydsl.version}</version>
            <scope>provided</scope>
        </dependency>
 
        <dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-jpa</artifactId>
            <version>${querydsl.version}</version>
        </dependency>
 
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.6.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
            <version>2.9.0</version>
        </dependency>
        <!--JPA dependency-->
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.1.11.Final</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-jpa -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>2.0.2.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
        <!-- <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> 
            <version>${org.springframework-version}</version> </dependency> -->
 
        <!-- oracle -->
        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.2.0.3</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ucp</artifactId>
            <version>11.2.0.3</version>
            <scope>compile</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-dbcp2 -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.0</version>
        </dependency>
 
        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>
 
        <!-- AspectJ -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>${org.aspectj-version}</version>
        </dependency>
 
        <!-- Logging -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${org.slf4j-version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>${org.slf4j-version}</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${org.slf4j-version}</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.15</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.mail</groupId>
                    <artifactId>mail</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.jms</groupId>
                    <artifactId>jms</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jdmk</groupId>
                    <artifactId>jmxtools</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jmx</groupId>
                    <artifactId>jmxri</artifactId>
                </exclusion>
            </exclusions>
            <scope>runtime</scope>
        </dependency>
 
        <!-- @Inject -->
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>
 
        <!-- Servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
 
        <!-- Test -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.7</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.9</version>
                <configuration>
                    <additionalProjectnatures>
                        <projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
                    </additionalProjectnatures>
                    <additionalBuildcommands>
                        <buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
                    </additionalBuildcommands>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>true</downloadJavadocs>
                </configuration>
            </plugin>
            <!--maven plugin 추가-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <configuration>
                    <!-- 사용할 자바버전 -->
                    <source>1.8</source>
                    <target>1.8</target>
                    <compilerArgument>-Xlint:all</compilerArgument>
                    <showWarnings>true</showWarnings>
                    <showDeprecation>true</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.2.1</version>
                <configuration>
                    <mainClass>org.test.int1.Main</mainClass>
                </configuration>
            </plugin>
            <plugin>
                <groupId>com.mysema.maven</groupId>
                <artifactId>apt-maven-plugin</artifactId>
                <version>1.1.3</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>process</goal>
                        </goals>
                        <configuration>
                            <!--Q클래스들이 생성될 위치입니다.-->
                            <outputDirectory>target/generated-sources/java</outputDirectory>
                            <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>
 

Entity class 작성

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package com.spring.jpa.model;
 
import java.io.Serializable;
import java.util.Date;
 
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.PrePersist;
import javax.persistence.Table;
 
@Entity
@Table(name="TBL_USER")
public class UserEntity implements Serializable{
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="USER_ID")
    private long id;
    
    private String userName;
    private int age;
    private Date createdAt;
    @Column(name="role")
    @Enumerated(EnumType.ORDINAL) //ORDINAL -> int로 할당 STRING -> 문자열로 할당 
    private UserRole role;
    
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name="NATION_ID")
    private NationEntity nationEntity;
    
    @PrePersist
    public void beforeCreate() {
        createdAt=new Date();
    }
    
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public Date getCreatedAt() {
        return createdAt;
    }
    public void setCreatedAt(Date createdAt) {
        this.createdAt = createdAt;
    }
 
    public UserRole getRole() {
        return role;
    }
 
    public void setRole(UserRole role) {
        this.role = role;
    }
 
    public NationEntity getNationEntity() {
        return nationEntity;
    }
 
    public void setNationEntity(NationEntity nationEntity) {
        this.nationEntity = nationEntity;
    }
    
    
}
 

package com.spring.jpa.model;
 
import java.util.Set;
 
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;
 
@Entity
@Table(name="TBL_NATION")
public class NationEntity {
    
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="NATION_ID")
    private long id;
    private String nationName;
    private String nationCode;
    
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getNationName() {
        return nationName;
    }
    public void setNationName(String nationName) {
        this.nationName = nationName;
    }
    public String getNationCode() {
        return nationCode;
    }
    public void setNationCode(String nationCode) {
        this.nationCode = nationCode;
    }
    
}
 

maven plugin에서 JpaAnnotationProccesor가 @Entity를 보고 관련 Q클래스를 생성해줍니다.

maven build

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run 해주면 target>generate-sources/java에 해당 Q클래스들이 생성됩니다. 만약 생성이 되었지만 Q클래스들을 인식하지 못하였을 경우에는 build path에 해당 폴더를 add folder해줍니다. 

Repository 작성

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package com.spring.jpa.repository;
 
import java.util.List;
 
import com.spring.jpa.model.UserEntity;
 
public interface JpaUserRepositoryCustom {
    List<UserEntity> findAllLike(String keyword);
}
 

커스텀레포지터리를 작성해줍니다.

package com.spring.jpa.repository;
 
import java.util.List;
 
import javax.persistence.EntityManager;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.support.QuerydslRepositorySupport;
import org.springframework.stereotype.Repository;
 
import com.querydsl.jpa.JPQLQuery;
import com.spring.jpa.model.QUserEntity;
import com.spring.jpa.model.UserEntity;
 
@Repository
public class JpaUserRepositoryImpl extends QuerydslRepositorySupport implements JpaUserRepositoryCustom{
 
    public JpaUserRepositoryImpl() {
        super(UserEntity.class);
        // TODO Auto-generated constructor stub
    }
 
    @Override
    @Autowired
    public void setEntityManager(EntityManager entityManager) {
        super.setEntityManager(entityManager);
    }
 
    @Override
    public List<UserEntity> findAllLike(String keyword) {
        // TODO Auto-generated method stub
        QUserEntity qUserEntity=QUserEntity.userEntity;
        JPQLQuery<UserEntity> query=from(qUserEntity);
        List<UserEntity> userEntityList=query.where(qUserEntity.userName.like(keyword)).fetch();
        return userEntityList;
    }
 
}
 

커스텀레포지터리 구현체를 만들어줍니다. 주의해야할점은 생성자에서 super(domain.class)입니다. 도메인클래스 인자는 해당 구현체가 필요한 것이 아니라, QuerydslRepositorySupport이 필요한 인자입니다. 꼭 넣어주어야합니다 !!!!

그리고 커스텀인터페이스에서 선언한 메소드를 오버라이드하여, querydsl을 이용한 type-safe한 동적인 쿼리를 작성해줍니다. 여기서 querydsl은 일반 Jpa 레포지토리의 기능을 업그레이드 해주는 역할이라고 보시면 됩니다. 

package com.spring.jpa.repository;
 
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;
 
import com.spring.jpa.model.UserEntity;
 
@Repository("jpaUserRepository")
public interface JpaUserRepository extends JpaRepository<UserEntity, Long>,JpaUserRepositoryCustom{
 
    UserEntity findByUserName(String userName);
    
    @Query(value="SELECT * FROM TBL_USER WHERE USERNAME=?1 AND AGE=?2",nativeQuery=true)
    UserEntity findByUserNameAndAge(String userName,int age);
}
 

일반 Jpa 레포지토리에 커스텀인터페이스 상속을 해줍니다. 이렇게 커스텀인터페이스를 상속해주면 커스텀인터페이스 구현체에서 구현한 querydsl 메소드를 일반 jpa레포지토리에서 사용이 가능해집니다. 즉, 일반 jpa레포지터리의 기능을 그대로 이용하면서 업그레이드된 querydsl쿼리를 같이 이용할 수 있게 되는 것입니다.

Controller 작성

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대충짰습니다....controller에서 repository를 다이렉트로 주입하고... 따라하시지 마시고 테스트용도이니 만약 사용하실때는 꼭 controller->service->repository 구조로 이용해주세요 !!!!

package com.spring.jpa.controller;
 
import java.util.Arrays;
import java.util.List;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
 
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.spring.jpa.model.NationEntity;
import com.spring.jpa.model.UserEntity;
import com.spring.jpa.model.UserRole;
import com.spring.jpa.repository.JpaNationRepository;
import com.spring.jpa.repository.JpaUserRepository;
import com.spring.jpa.service.UserService;
 
@Controller
public class UserController {
    
    private final static Logger log=LoggerFactory.getLogger(UserController.class);
    
    @Autowired
    UserService userService;
    @Autowired
    JpaNationRepository jpaNationRepository;
    @Autowired
    JpaUserRepository jpaUserRepository;
    
    @GetMapping("/user")
    public String getUserView() {
        return "user";
    }
    
    @GetMapping("/usersave")
    public String saveUser(ModelMap map,UserEntity userEntity,NationEntity nationEntity) throws JsonProcessingException {
        
        nationEntity.setNationCode("KR");
        nationEntity.setNationName("대한민국");
        jpaNationRepository.save(nationEntity);
        
        userEntity.setUserName("여성게");
        userEntity.setAge(27);
        userEntity.setRole(UserRole.USER);
        userEntity.setNationEntity(nationEntity);
        userService.save(userEntity);
        
        UserEntity saveUser=userService.findByUserName("여성게");
        UserEntity user=userService.findByUserNameAndAge(saveUser.getUserName(), saveUser.getAge());
        log.info("username={},user age={}",user.getUserName(),user.getAge());
        log.info("nationCode={},nationName={}",user.getNationEntity().getNationCode(),user.getNationEntity().getNationName());
        
        XmlMapper xmlMapper=new XmlMapper();
        String xmlString=xmlMapper.writeValueAsString(user);
        
        log.info(xmlString);
        
        List<UserEntity> userList=jpaUserRepository.findAllLike("여성게");
        log.info("userEntity list={}",userList.get(0).getUserName());
        
        map.addAttribute("userEntity", saveUser);
        return "userlist";
    }
}
 

확실히.. 편하긴 하지만 여기까지 오기에 복잡한 설정은 아니지만 귀찮은 설정들이 많았내요... 조금 적응되면 이 기술도 자유롭게 사용가능하겠죠? mybatis를 선호하였던 저였지만, jpa+querydsl을 잠시나마 사용해보니 확실히 기술을 익히고 사용한다면 mybatis보다 훨씬 유연한 데이터베이스 관련 기술 일것 같습니다.

혹시 여기까지 오시다가 cannot change web module version 2.5 to ....어쩌고 맞나?.. 이런 에러가 뜬다면 자기가 사용중인 web module 버전과 maven에 명시되어 있는 버전과 비교를 하시고 꼭 maven jdk 버전이랑도 같이 맞춰주시면 해당 에러는 사라집니다... 설정을 다 다시 마추고 maven update하면 에러는 싹 사라집니다.