java - 在 Spring Batch 中将 jobParameters 传递给 bean

Question

我从链接 https://stackoverflow.com/q/15784984/814074 读到一个问题并尝试了上面链接中给出的解决方案。但是，我在运行代码时遇到以下错误:

Error creating bean with name 'JobArgs' defined in class path resource [pipelineJob.xml]: 
Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type '$Proxy2 implementing java.io.Serializable,org.springframework.aop.scope.ScopedObject,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'com.test.genepanel.job.JobArguments' for property 'jobArguements'; nested exception is java.lang.IllegalStateException:
Cannot convert value of type [$Proxy2 implementing java.io.Serializable,org.springframework.aop.scope.ScopedObject,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [com.test.genepanel.job.JobArguments] for property 'jobArguements': no matching editors or conversion strategy found

xml 包含

   <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:batch="http://www.springframework.org/schema/batch"
     xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
            http://www.springframework.org/schema/batch
            http://www.springframework.org/schema/batch/spring-batch-2.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
            http://www.springframework.org/schema/util
            http://www.springframework.org/schema/util/spring-util-2.5.xsd">

    <batch:job id="pipelineJob">
        <batch:step id="initializationStep" next="CleanUPStep">
            <batch:tasklet ref="initializationStepTasklet" />
        </batch:step>
        <batch:step id="CleanUPStep">
            <batch:tasklet ref="cleanupTaskLet" />
        </batch:step>
    </batch:job>



    <bean id="basicStep" class="com.test.mutation.steps.BasicStep" abstract="true">
        <property name="testJobArgs" ref="JobArgs"/>
    </bean>

    <bean id="JobArgs" class="com.test.mutation.application.TestJobArguements">
        <property name="jobArguements" ref="jobArg"> 
        </property>
    </bean>

    <bean id="jobArg" class="com.test.genepanel.job.JobArguments" scope="step">
        <constructor-arg value="#{jobParameters['jobOutputDir']}"/>
    </bean>

    <bean id="emptyTaskLet" class="com.test.mutation.steps.EmptyStep" scope="step" parent="basicStep" />

    <bean id="cleanupTaskLet" class="com.test.mutation.steps.CleanUpStep" scope="step" parent="basicStep">
    </bean>

    <bean id="initializationStepTasklet" class="com.test.mutation.steps.InitializationStep"  scope ="step" parent="basicStep">
    </bean> 
</beans>

我错过了什么吗？

Answer 1

使用步骤范围的简单方法如下:

<bean id="myReader" class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
    <property name="resource" value="file:#{jobParameters['input.file']}" />
    <property name="linesToSkip" value="0" />
    <property name="recordSeparatorPolicy" ref="simpleRecordPolicy" />
    <property name="lineMapper" ref="journalSicIemtLineMapper" />
</bean>

将步骤范围放在 bean 上将延迟他的创建，直到他引用的步骤即将开始。这就是后期绑定(bind)的含义，因此您可以访问 ExecutionContext 中的变量。

正如 StepScope 中的文档所述:

beans with the StepScope will be aop:scoped-proxy. This means a proxy goes around the real object.

因此，当您定义常规 Spring Beans(就像您对 jobArg 所做的那样)并在其上添加scope=step 时。当您想在另一个 bean (JobArgs) 中设置对象时，您必须找到一种方法来检索该代理内的对象