Question

使用apt-maven-plugin生成QueryDSL的Q ...类时，maven构建在NullPointerException中失败，SimpleSerializerConfig - 但仅限于3.1.0以后的maven版本。

我们已经尝试调试maven版本，但这并没有得出任何结论。

maven配置如下所示：

<plugin>
    <groupId>com.mysema.maven</groupId>
    <artifactId>apt-maven-plugin</artifactId>
    <version>1.1.1</version>
    <executions>
        <execution>
            <goals>
                <goal>process</goal>
            </goals>
            <configuration>
                <outputDirectory>target/generated-sources/java</outputDirectory>
                <processor>com.mysema.query.apt.jpa.JPAAnnotationProcessor</processor>
                <logOnlyOnError>true</logOnlyOnError>
            </configuration>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>com.mysema.querydsl</groupId>
            <artifactId>querydsl-apt</artifactId>
            <version>${querydsl.version}</version>
        </dependency>
        <dependency>
            <groupId>com.mysema.querydsl</groupId>
            <artifactId>querydsl-jpa</artifactId>
            <classifier>apt</classifier>
            <version>${querydsl.version}</version>
        </dependency>
    </dependencies>
</plugin>

${querydsl.version}为2.9.0 - 使用较新的版本无法解决问题。

确切的堆栈跟踪是

java.lang.RuntimeException: java.lang.NullPointerException
    at com.sun.tools.javac.main.Main.compile(Main.java:469)
    at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:132)
    at com.mysema.maven.apt.AbstractProcessorMojo.execute(AbstractProcessorMojo.java:314)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:106)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:318)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:153)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:555)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:158)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:414)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:357)
Caused by: java.lang.NullPointerException
    at com.mysema.query.codegen.SimpleSerializerConfig.getConfig(SimpleSerializerConfig.java:29)
    at com.mysema.query.apt.DefaultConfiguration.<init>(DefaultConfiguration.java:129)
    at com.mysema.query.apt.jpa.JPAConfiguration.<init>(JPAConfiguration.java:69)
    at com.mysema.query.apt.jpa.JPAAnnotationProcessor.createConfiguration(JPAAnnotationProcessor.java:46)
    at com.mysema.query.apt.AbstractQuerydslProcessor.process(AbstractQuerydslProcessor.java:102)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:793)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:722)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$1700(JavacProcessingEnvironment.java:97)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1029)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1163)
    at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1108)
    at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:824)
    at com.sun.tools.javac.main.Main.compile(Main.java:439)
    ... 23 more

Answer 1

当构建中存在依赖冲突时，通常会发生此异常。尝试禁用apt执行，看看构建中是否还有其他问题。

Answer 2

我们也碰到了这个。我们注意到原因直接与注释有关。我们在Maven本身能够解决的类中添加了一个注释，但mysema却没有。我们明确地将编译依赖项添加到有问题的pom中，一切都解决了。

Answer 3

只是分享我的经验与类似的错误，但不同的原因，以防其他人遇到这种情况。

从测试范围的依赖项向src / main / java中的类添加注释后出现相同的错误。 Eclipse并没有抱怨，因为m2eclipse并不擅长区分编译和测试范围的依赖关系，只是将所有依赖项添加到项目类路径中，无论范围如何。

要查看实际的编译错误，我必须执行以下步骤：

make m2e-apt在Eclipse中生成QueryDsl类
从项目的POM
运行mvn compile（不clean不删除步骤1中生成的类）

自3.1.0以来，使用maven生成QueryDSL类失败

3 个答案: