Question

我正在尝试使用JSR-352 API和Spring Batch 3.0.4作为实现来实现示例批处理应用程序。

在创建名为'batchPropertyPostProcessor'的bean的错误的初始化阶段，批处理作业执行失败：

Exception in thread "main" javax.batch.operations.JobStartException: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'batchPropertyPostProcessor': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.batch.core.jsr.launch.support.BatchPropertyBeanPostProcessor.setBatchPropertyContext(org.springframework.batch.core.jsr.configuration.support.BatchPropertyContext); nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [dataListingStepListener] for bean with name 'scopedTarget.dataListingStepListener' defined in null; nested exception is java.lang.ClassNotFoundException: dataListingStepListener
    at org.springframework.batch.core.jsr.launch.JsrJobOperator.start(JsrJobOperator.java:637)
    at x98.BatchRunner.main(BatchRunner.java:18)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'batchPropertyPostProcessor': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.batch.core.jsr.launch.support.BatchPropertyBeanPostProcessor.setBatchPropertyContext(org.springframework.batch.core.jsr.configuration.support.BatchPropertyContext); nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [dataListingStepListener] for bean with name 'scopedTarget.dataListingStepListener' defined in null; nested exception is java.lang.ClassNotFoundException: dataListingStepListener
    at org.springframework.batch.core.jsr.configuration.support.SpringAutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(SpringAutowiredAnnotationBeanPostProcessor.java:262)
    at org.springframework.batch.core.jsr.configuration.support.JsrAutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(JsrAutowiredAnnotationBeanPostProcessor.java:30)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:232)
    at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:618)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:467)
    at org.springframework.batch.core.jsr.launch.JsrJobOperator.start(JsrJobOperator.java:635)
    ... 1 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.batch.core.jsr.launch.support.BatchPropertyBeanPostProcessor.setBatchPropertyContext(org.springframework.batch.core.jsr.configuration.support.BatchPropertyContext); nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [dataListingStepListener] for bean with name 'scopedTarget.dataListingStepListener' defined in null; nested exception is java.lang.ClassNotFoundException: dataListingStepListener
    at org.springframework.batch.core.jsr.configuration.support.SpringAutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(SpringAutowiredAnnotationBeanPostProcessor.java:575)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.batch.core.jsr.configuration.support.SpringAutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(SpringAutowiredAnnotationBeanPostProcessor.java:259)
    ... 13 more
Caused by: org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [dataListingStepListener] for bean with name 'scopedTarget.dataListingStepListener' defined in null; nested exception is java.lang.ClassNotFoundException: dataListingStepListener
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1325)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:594)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isTypeMatch(AbstractBeanFactory.java:526)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:387)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:354)
    at org.springframework.beans.factory.BeanFactoryUtils.beanNamesForTypeIncludingAncestors(BeanFactoryUtils.java:187)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1002)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
    at org.springframework.batch.core.jsr.configuration.support.SpringAutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(SpringAutowiredAnnotationBeanPostProcessor.java:532)
    ... 15 more
Caused by: java.lang.ClassNotFoundException: dataListingStepListener
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:247)
    at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1346)
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1317)
    ... 24 more

我的批处理员：

public class BatchRunner {

    public static void main(String[] args) {

        System.setProperty("JSR-352-BASE-CONTEXT", "x98_batch_local.xml");

        Properties jobParameters = new Properties();
        jobParameters.put("message", "Hello!");

        JobOperator jobOperator = BatchRuntime.getJobOperator();
        jobOperator.start("x98SampleJob", jobParameters);

    }
}

我的sampleJob定义：

<?xml version="1.0" encoding="UTF-8"?>
<job id="x98SampleJob" xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/jobXML_1_0.xsd"
    version="1.0">

    <step id="simple" next="dataListing">
        <batchlet ref="simpleBatchlet">
            <properties>
                <property name="message" value="#{jobParameters['message']}" />
            </properties>
        </batchlet>
    </step>

    <step id="dataListing">
        <listeners>
            <listener ref="dataListingStepListener"/>
        </listeners>
        <chunk item-count="3">
            <reader ref="dataListingItemReader" />
            <processor ref="dataListingItemProcessor"/>
            <writer ref="dataListingItemWriter"/>
        </chunk>
    </step>
</job>

我的读者，作家，处理器和监听器的Spring bean配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jee="http://www.springframework.org/schema/jee"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.1.xsd">

    <import resource="classpath*:x98_services.xml"/>

    <bean name="simpleBatchlet" class="x98.batch.SimpleBatchlet"/>

    <bean name="dataListingItemProcessor" class="x98.batch.DataListingItemProcessor"/>

    <bean name="dataListingItemReader" class="x98.batch.DataListingItemReader">
        <property name="tx98DatasService" ref="tx98DatasService"/>
        <property name="tx98StructureService" ref="tx98StructureService"/>
    </bean>

    <bean name="dataListingItemWriter" class="x98.batch.DataListingItemWriter"/>

    <bean name="dataListingStepListener" class="x98.batch.DataListingStepListener">
        <property name="tx98StatusService" ref="tx98StatusService"/>
    </bean>
</beans>

读取器，编写器和处理器由Spring实例化，并在作业运行中正确使用。当我将监听器添加到作业定义时，它停止工作。

我调试了代码，我看到在Spring上下文中初始化了dataListingStepListener bean。我不明白为什么对侦听器（<listener ref="dataListingStepListener"/>）的引用不被识别为Spring bean而Spring正在尝试加载名为“dataListingStepListener”的类。

我的配置好吗？我做错了吗？

Answer 1

在阅读了Gist之后，有几个笔记：

作业特定bean必须位于子上下文中
Spring Batch的JSR-352上下文管理通过父/子关系工作。父上下文由baseContext.xml定义，或者可以通过系统属性JSR-352-BASE-CONTEXT覆盖。该上下文仅用于基础结构bean，并且不会由JSR-352后处理器处理，例如属性注入。你说“当我将监听器添加到工作定义时，它停止了工作。”如果您密切关注，当作业运行时，您的属性未被注入SimpleBatchlet（消息为null）。

原因是如果要运行多个作业，则不需要创建多个JobRepository实例，多个连接池等，因此我们只引导父上下文一次。由于我们只引导一次，因此我们没有像当时注入的作业属性那样的值（并且它们可能会因作业而改变）。

因此，所有特定于作业的bean都应该在子上下文中。

为JSR-352定义子上下文
JSR-352提供了三种处理bean创建的方法：

内联 - 在作业XML中的工件定义的ref属性中提供完全限定的类名，并使用no-arg构造函数创建它。
batch.xml - batch.xml文件提供了一种通过为类名提供别名来简化上述概念的方法。
特定于实现的DI（本例中为Spring DI） - Spring Batch的JSR-352实现提供了使用Spring的DI工具创建bean的能力。

有了这个，我们就如何创建bean实例来控制你。默认情况下，在Spring中，bean是在启动时创建的单例。但是，Spring Batch提供范围（step或job）以允许后期绑定属性。如果要进行属性注入，则必须将bean定义为step范围（SimpleBatchlet不是第一次运行时消息为null的原因。

那么在定义作业的上下文时，如何实现Spring DI和基于标准的JSR-352之间的关注点分离？简单。将作业XML导入Spring XML，并将Spring XML名称传递给要启动的JobOperator。在你的情况下，而不是：

public static void main(String[] args) {

    System.setProperty("JSR-352-BASE-CONTEXT", "x98_batch_local.xml");

    Properties jobParameters = new Properties();
    jobParameters.put("message", "Hello!");

    JobOperator jobOperator = BatchRuntime.getJobOperator();
    jobOperator.start("x98SampleJob", jobParameters);

}

将以下内容添加到x98_batch_local.xml：

<import resource="classpath*:x98SampleJob.xml"/>

然后通过以下方式执行您的工作：

public static void main(String[] args) {

    Properties jobParameters = new Properties();
    jobParameters.put("message", "Hello!");

    JobOperator jobOperator = BatchRuntime.getJobOperator();
    jobOperator.start("x98_batch_local.xml", jobParameters);

}

上述调整并将SimpleBatchlet设置为步骤范围将导致您的作业按预期运行。

注意：由于这个问题，我创建了问题BATCH-2388，以便更好地记录上面讨论的上下文考虑因素。

创建名为“batchPropertyPostProcessor”的bean时，批处理作业初始化失败

1 个答案: