Question

我在com.querydsl中自动生成Q classess有问题。我知道com.query.dsl和spring-boot-jpa之间的兼容性可能存在错误，但我尝试了很多版本而没有任何正面结果。这是我的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>

错误

引起：org.springframework.beans.BeanInstantiationException：无法实例化[org.springframework.data.jpa.repository.support.QueryDslJpaRepository]：构造函数抛出异常;嵌套异常是java.lang.IllegalArgumentException：没有为域类com.coig.prek.webservice.modules.quiz.entiry.Quiz找到查询类com.coig.prek.webservice.modules.quiz.entiry.QQuiz！在org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:154）〜[spring-beans-4.3.6.RELEASE.jar：4.3.6.RELEASE] 在org.springframework.data.repository.core.support.RepositoryFactorySupport.getTargetRepositoryViaReflection（RepositoryFactorySupport.java:365）〜[spring-data-commons-1.13.0.RELEASE.jar：na] 在org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository（JpaRepositoryFactory.java:101）〜[spring-data-jpa-1.11.0.RELEASE.jar：na] 在org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository（JpaRepositoryFactory.java:81）〜[spring-data-jpa-1.11.0.RELEASE.jar：na] 在org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository（RepositoryFactorySupport.java:199）〜[spring-data-commons-1.13.0.RELEASE.jar：na] 在org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn（RepositoryFactoryBeanSupport.java:277）〜[spring-data-commons-1.13.0.RELEASE.jar：na] 在org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet（RepositoryFactoryBeanSupport.java:263）〜[spring-data-commons-1.13.0.RELEASE.jar：na] 在org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet（JpaRepositoryFactoryBean.java:101）〜[spring-data-jpa-1.11.0.RELEASE.jar：na] 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods（AbstractAutowireCapableBeanFactory.java:1687）〜[spring-beans-4.3.6.RELEASE.jar：4.3.6.RELEASE] 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean（AbstractAutowireCapableBeanFactory.java:1624）〜[spring-beans-4.3.6.RELEASE.jar：4.3.6.RELEASE] ...省略了47个常见帧引起：java.lang.IllegalArgumentException：没有为域类com.coig.prek.webservice.modules.quiz.entiry.Quiz找到查询类com.coig.prek.webservice.modules.quiz.entiry.QQuiz！在org.springframework.data.querydsl.SimpleEntityPathResolver.createPath（SimpleEntityPathResolver.java:63）〜[spring-data-commons-1.13.0.RELEASE.jar：na] 在org.springframework.data.jpa.repository.support.QueryDslJpaRepository。（QueryDslJpaRepository.java:84）〜[spring-data-jpa-1.11.0.RELEASE.jar：na] 在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] 在java.lang.reflect.Constructor.newInstance（Constructor.java:423）〜[na：1.8.0_111] 在org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:142）〜[spring-beans-4.3.6.RELEASE.jar：4.3.6.RELEASE] ...省略了56个常见帧引起：java.lang.ClassNotFoundException：com.coig.prek.webservice.modules.quiz.entiry.QQuiz at java.net.URLClassLoader.findClass（URLClassLoader.java:381）〜[na：1.8.0_111] 在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] 在java.lang.ClassLoader.loadClass（ClassLoader.java:357）〜[na：1.8.0_111] 在org.springframework.util.ClassUtils.forName（ClassUtils.java:250）〜[spring-core-4.3.6.RELEASE.jar：4.3.6.RELEASE] 在org.springframework.data.querydsl.SimpleEntityPathResolver.createPath（SimpleEntityPathResolver.java:53）〜[spring-data-commons-1.13.0.RELEASE.jar：na] ...省略了63个常见帧

存储库：

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

和实体：

@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() {}

}

你能告诉我我是否遗漏了什么，或者我做错了什么？谢谢你的帮助。

Answer 1

以下是有关如何使用QueryDSL的示例：

在pom.xml文件中包含以下依赖项：

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

此外，请包含以下插件以生成Q类：

            <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>

现在，创建一个名为QuizRepositoryCustom的新存储库接口，并定义要提供的方法。

public interface QuizRepositoryCustom {

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

}

创建QuizRepositoryCustom的实现。此类应扩展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);
    }

}

现在，从QuizRepository和JpaRepository<Quiz, Long>界面扩展QuizRepositoryCustom界面。

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

}

通过这些简单的步骤，您就可以使用QueryDSL。

此外，您可以查看以下项目，其中包含有关如何使用QueryDSL的更多示例。

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

希望它有所帮助，

Answer 2

几天前，我也遇到了这个问题！！但这与您的问题有点不同，它类似于：

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]

但是我认为这值得尝试：

这是场景：：我克隆了一个具有querydsl实现并正在使用STS IDE的项目。

在下载所有依赖项时，我运行了该项目并成功运行，但是在访问任何端点时，上述错误开始提示！！

这就是我要做的：

我进入.m2文件夹，删除了querydsl-jpa中的com/querydsl directory文件夹，然后手动运行mvn clean [ install for war | package for jar ]，下载了所有依赖项并正确链接了它们！ / p>

重新运行spring项目时，一切工作正常。

此问题的原因：有时从maven或任何其他存储库下载依赖项时，jar文件可能会损坏，这在执行之前是无法检测到的，因此删除.m2文件夹中的jar是有益的并且有时会手动运行，因为IDE也会破坏下载的jar。

希望这可以解决您的问题！

QuerydslPredicate with spring-boot-starter-jpa

2 个答案: