[FIXED] Query DSL Q type classes not generated

Issue

I am trying to use QueryDSL in my eclipse maven project. These are the dependencies.

<properties>
        <!-- The main class to start by executing java -jar -->
        <start-class>my.app.market.DBApp</start-class>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <querydsl.version>4.1.4</querydsl.version>
        <apt-maven-plugin.version>1.1.3</apt-maven-plugin.version>

</properties>

<dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-apt</artifactId>
            <version>4.1.4</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-jpa</artifactId>
            <version>4.1.4</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.6.1</version>
        </dependency>

<build>
        <plugins>
            <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</outputDirectory>
                            <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

After this I try to write the queries.

@Repository
public class QueryDSLRepo {

    @PersistenceContext
    private EntityManager em;

    public ReportingParamDAO save(final ReportingParamDAO reportingParamDAO) {
        em.persist(reportingParamDAO);
        return reportingParamDAO;
    }

    public List<ReportingParamDAO> findreportingParamDAOsByIdQueryDSL(final Integer id) {
        final JPAQuery<ReportingParamDAO> query = new JPAQuery<>(em);
        final QReportingParamDAO reportingParamDAO = QReportingParamDAO.reportingParamDAO;

        return query.from(reportingParamDAO).where(reportingParamDAO.id.eq(id)).fetch();
    }


}

But I get the error

QReportingParamDAO cannot be resolved to a type

Note: ReportingParamDAO is an entity class.

This means that the Q type class for my DAO is not generated. I am not sure why it wasn't generated. Do I need to do something else? I came across this post but the user is working on IntelliJ and I can't seem to make it work in my case. Can someone please help me. Thanks !!

Solution

I have tested with your pom.xml. The Q classes were generated for me but I couldn't access them from my source code. The problem is that the generated-sources is not on classpath by default. Add that on the classpath and you will be able to use them in your source code.

1. Check the target/generated-sources directory to see if the classes are actually there. (You should be able to find them because I tested with your pom.xml)
2. If you add target/generated-sources to classpath, you application will work. But I don't think that is a good idea. Because all the files in the classpath will be indexed by the IDE and your IDE will be slower. All the files in the generated-sources folder need not be indexed. So add target/generated-sources/java to classpath and change your query-dsl plugin to generated Q class to target/generated-sources/java

Answered By - yaswanth
Answer Checked By - Robin (JavaFixing Admin)