Querydsl 不在 Spring Boot 中创建元模型答案

【问题标题】：Querydsl not create Metamodel in Spring BootQuerydsl 不在 Spring Boot 中创建元模型
【发布时间】：2019-05-01 04:41:33
【问题描述】：

我正在尝试在 Spring Boot 2.1.4.RELEASE 中使用 Querydsl，但由于未生成元模型而失败。
这是错误信息：

Caused by: java.lang.ClassNotFoundException: com.example.MyApp.model.QProduct

这是我的 pom.xml：

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>MyApp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>MyApp</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-jpamodelgen</artifactId>
            <scope>provided</scope>
        </dependency>

        <dependency>
          <groupId>com.querydsl</groupId>
          <artifactId>querydsl-apt</artifactId>
          <scope>provided</scope>
        </dependency>

        <dependency>
          <groupId>com.querydsl</groupId>
          <artifactId>querydsl-jpa</artifactId>
        </dependency>
    </dependencies>

    <build>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </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>
                                <outputDirectory>target/generated-sources/java</outputDirectory>
                                <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
                            </configuration>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>com.mysema.querydsl</groupId>
                            <artifactId>querydsl-apt</artifactId>
                            <version>${querydsl.version}</version>
                        </dependency>
                        <dependency>
                            <groupId>com.mysema.querydsl</groupId>
                            <artifactId>querydsl-jpa</artifactId>
                            <version>${querydsl.version}</version>
                        </dependency>
                    </dependencies>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

</project>

我试图将项目作为 Maven 生成源运行，Maven 构建目标：编译，但仍然没有创建 Metamodel 类，甚至生成源文件夹中不存在 java 文件夹。

我正在使用 Spring Tools Suite 3.9.4.RELEASE。
如何解决这个问题...？

【问题讨论】：

标签： spring-boot querydsl

【解决方案1】：

删除pluginmanagement xml 标记注释掉在mysema 插件中定义的依赖项，您的Q-classes 将被生成。您的插件应如下所示：

<build>
    <!--<pluginManagement>--> // Remove pluginManagement
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>com.mysema.maven</groupId>
            <artifactId>maven-apt-plugin</artifactId>
            <version>1.0</version>
            <executions>
                <execution>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>process</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/generated-sources</outputDirectory>
                        <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
    <!--</pluginManagement>-->
</build>

【讨论】：

我已经删除了插件中的依赖，但还是不行。
对不起，我忘了通知也要删除pluginManagement xml 标签。我已经更新了答案。