QuerydslPredicate with spring-boot-starter-jpa

Question

I have a problem with autogenerating Q classess in com.querydsl. I know that there are possible mistakes with compatibility between com.query.dsl and spring-boot-jpa but i tried lots of version without any positive result. Here is my pom.xml

    <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-rest</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.4.1212.jre7</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-dbcp2</artifactId>
        <version>2.1.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.4</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.16.12</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
        <version>1.4.3.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>21.0</version>
    </dependency>
    <dependency>
        <groupId>commons-beanutils</groupId>
        <artifactId>commons-beanutils</artifactId>
        <version>1.9.3</version>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <version>2.6.1</version>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>2.6.1</version>
    </dependency>
    <dependency>
        <groupId>com.querydsl</groupId>
        <artifactId>querydsl-jpa</artifactId>
        <version>4.0.7</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>com.mysema.maven</groupId>
            <artifactId>apt-maven-plugin</artifactId>
            <version>1.1.3</version>
            <executions>
                <execution>
                    <id>process-common-model</id>
                    <goals>
                        <goal>process</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>target/generated-sources/apt</outputDirectory>
                        <processors>
                            <processor>com.query.apt.jpa.JPAAnnotationProcessor</processor>
                        </processors>
                    </configuration>
                </execution>
            </executions>
            <dependencies>
                <dependency>
                    <groupId>com.querydsl</groupId>
                    <artifactId>querydsl-apt</artifactId>
                    <version>4.0.7</version>
                </dependency>
            </dependencies>
        </plugin>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

The error

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.jpa.repository.support.QueryDslJpaRepository]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: Did not find a query class com.coig.prek.webservice.modules.quiz.entiry.QQuiz for domain class com.coig.prek.webservice.modules.quiz.entiry.Quiz! at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:154) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE] at org.springframework.data.repository.core.support.RepositoryFactorySupport.getTargetRepositoryViaReflection(RepositoryFactorySupport.java:365) ~[spring-data-commons-1.13.0.RELEASE.jar:na] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:101) ~[spring-data-jpa-1.11.0.RELEASE.jar:na] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:81) ~[spring-data-jpa-1.11.0.RELEASE.jar:na] at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:199) ~[spring-data-commons-1.13.0.RELEASE.jar:na] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:277) ~[spring-data-commons-1.13.0.RELEASE.jar:na] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:263) ~[spring-data-commons-1.13.0.RELEASE.jar:na] at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:101) ~[spring-data-jpa-1.11.0.RELEASE.jar:na] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE] ... 47 common frames omitted Caused by: java.lang.IllegalArgumentException: Did not find a query class com.coig.prek.webservice.modules.quiz.entiry.QQuiz for domain class com.coig.prek.webservice.modules.quiz.entiry.Quiz! at org.springframework.data.querydsl.SimpleEntityPathResolver.createPath(SimpleEntityPathResolver.java:63) ~[spring-data-commons-1.13.0.RELEASE.jar:na] at org.springframework.data.jpa.repository.support.QueryDslJpaRepository.(QueryDslJpaRepository.java:84) ~[spring-data-jpa-1.11.0.RELEASE.jar:na] at org.springframework.data.jpa.repository.support.QueryDslJpaRepository.(QueryDslJpaRepository.java:68) ~[spring-data-jpa-1.11.0.RELEASE.jar:na] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_111] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_111] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_111] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_111] at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE] ... 56 common frames omitted Caused by: java.lang.ClassNotFoundException: com.coig.prek.webservice.modules.quiz.entiry.QQuiz at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_111] at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_111] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_111] at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_111] at org.springframework.util.ClassUtils.forName(ClassUtils.java:250) ~[spring-core-4.3.6.RELEASE.jar:4.3.6.RELEASE] at org.springframework.data.querydsl.SimpleEntityPathResolver.createPath(SimpleEntityPathResolver.java:53) ~[spring-data-commons-1.13.0.RELEASE.jar:na] ... 63 common frames omitted

Repository:

@Repository
public interface QuizRepository extends PagingAndSortingRepository<Quiz, Long>, QueryDslPredicateExecutor<Quiz> {
}

And Entity:

@javax.persistence.Entity
@Table(name = "QUIZ", uniqueConstraints = {
        @UniqueConstraint(columnNames = "NAME")
})
@ToString
public class Quiz extends Entity{

    @Column(name = "NAME")
    private @Setter @Getter String name;
    @Column(name = "TYPE")
    private @Setter @Getter Integer type;
    @Column(name = "TIME")
    private @Setter @Getter Long time;
    @JsonProperty(value = "branch")
    @Column(name = "BRANCH")
    private @Setter @Getter Integer branch;

    @OneToMany
    private @Setter @Getter Set<Question> questions;

    public Quiz() {}

}

Can you tell me if I missing something, or what I am doing wrong? Thanks for any help.

Answer 1

Few days before, I also faced this problem!! But it was a bit different to your problem it was something like:

Failed to introspect Class org.springframework.data.jpa.repository.support.QuerydslJpaRepository] from ClassLoader [sun.misc.Launcher$AppClassLoader@764c12b6]; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.data.jpa.repository.support.QuerydslJpaRepository] from ClassLoader [sun.misc.Launcher$AppClassLoader@764c12b6]

But I believe this is worth trying:

This is was the scenario: I cloned a project which has querydsl implementation and was using STS IDE.

On downloading all the dependencies I ran the project and was successful but upon accessing any endpoint the above error started to prompt up!!

For which this is what I did:

I went into the .m2 folder and deleted the querydsl-jpa folder present inside com/querydsl directory and then manually ran mvn clean [ install for war | package for jar ] which downloaded all the dependencies and linked them properly!!

Upon re-running spring project everything was working fine.

Causes of this issue: At times while downloading the dependencies from maven or any other repository the jar file could get corrupted which is undetectable before execution so it is beneficial to delete that jar in .m2 folder and running manually as at times IDE could also corrupt downloaded jars.

Hope this resolves your issue!!

Answer 2

Here's an example about how to use QueryDSL:

Include the following dependencies in your pom.xml file:

    <dependency>
        <groupId>io.springlets</groupId>
        <artifactId>springlets-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.querydsl</groupId>
        <artifactId>querydsl-jpa</artifactId>
    </dependency>

Also, include the following plugins to be able to generate the Q classes:

            <plugin>
                <groupId>com.mysema.maven</groupId>
                <artifactId>apt-maven-plugin</artifactId>
                <version>1.1.3</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>process</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>target/generated-sources/java</outputDirectory>
                            <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
                        </configuration>
                    </execution>
                </executions>
                <dependencies>
                    <dependency>
                        <groupId>com.querydsl</groupId>
                        <artifactId>querydsl-apt</artifactId>
                        <version>${querydsl.version}</version>
                    </dependency>
                    <dependency>
                        <groupId>com.querydsl</groupId>
                        <artifactId>querydsl-jpa</artifactId>
                        <version>${querydsl.version}</version>
                    </dependency>
                </dependencies>
            </plugin>

Now, creates a new repository interface called QuizRepositoryCustom and define the methods you want to provide.

public interface QuizRepositoryCustom {

  // SAMPLE METHOD TO SEARCH QUIZ BY NAME
  public Page<Quiz> findByNameLike(String name, Pageable pageable);

}

Creates the implementation of the QuizRepositoryCustom. This class should extends QueryDslRepositorySupport

public class QuizRepositoryImpl extends QueryDslRepositorySupport<Quiz> implements QuizRepositoryCustom {

    QuizRepositoryImpl() {
        super(Quiz.class);
    }

    public Page<Quiz> findByNameLike(String name, Pageable pageable) {

        QQuiz quiz = QQuiz.quiz;

        JPQLQuery<Quiz> query = from(quiz);

        if (StringUtils.isNotEmpty(name)) {
           BooleanBuilder searchCondition = new BooleanBuilder();                         

           searchCondition.and(quiz.name.eq(name));

           if (searchCondition.hasValue()) {
            query.where(searchCondition);
           }
        }

        long totalFound = query.fetchCount();
        List<Quiz> results = query.select(quiz).fetch();
        return new PageImpl<M>(results, pageable, totalFound);
    }

}

Now, extend the QuizRepository interface from JpaRepository<Quiz, Long> and QuizRepositoryCustom interface.

public interface QuizRepository extends QuizRepositoryCustom, JpaRepository<Quiz, Long> {

}

With that simple steps, you will be able to use QueryDSL.

Also, you could check the following project that contains more examples about how to use QueryDSL.

https://github.com/jcagarcia/proofs/tree/master/spring-security-and-formatters/src/main/java/org/springframework/roo/petclinic/repository

Hope it helps,