Spring Batch中的JobParameters

Question

我已经确定了大约10次运行中有一次jobparameters是可用的，即使没有代码或配置更改。这是一个随机成功而不是随机失败的案例，所以很难追踪。

我使用调试器深入研究了spring代码，并确定当此操作失败时，在注入发生时，spring中没有注册名为jobParameters的bean。

我使用Spring 4.1.4和spring-batch 3.0.2以及spring-data-jpa 1.7.1和spring-data-commons 1.9.1，运行在Java8中。

@Component("sourceSelectionReader")
@Scope("step")
public class SourceSelectionReaderImpl  
implements ItemReader<MyThing> {
    private Map<String,Object> jobParameters;

// ... snip ...


    @Autowired
    @Lazy
    @Qualifier(value="#{jobParameters}")
    public void setJobParameters(Map<String, Object> jobParameters) {
        this.jobParameters = jobParameters;
    }
}

launch-context.xml job1 jobid(long)=1

lown-context.xml（减去绒毛）：

<context:property-placeholder location="classpath:batch.properties" />

<context:component-scan base-package="com.maxis.maximo.ilm" />

<jdbc:initialize-database data-source="myDataSource"  enabled="false">
    <jdbc:script location="${batch.schema.script}" />
</jdbc:initialize-database>

<batch:job-repository id="jobRepository" 
    data-source="myDataSource"
    transaction-manager="transactionManager"
    isolation-level-for-create="DEFAULT"
    max-varchar-length="1000"/>

<import resource="classpath:/META-INF/spring/module-context.xml" />

module-context.xml（减去绒毛）：

<description>Example job to get you started. It provides a skeleton for a typical batch application.</description>

<import resource="classpath:/META-INF/spring/hibernate-context.xml"/>
<import resource="classpath:/META-INF/spring/myapp-context.xml"/>

<context:component-scan base-package="com.me" />
<bean class="org.springframework.batch.core.scope.StepScope" />

<batch:job id="job1">
    <batch:step id="step0002"  >            
        <batch:tasklet transaction-manager="transactionManager" start-limit="100" >
            <batch:chunk reader="sourceSelectionReader" writer="selectedDataWriter" commit-interval="1" />
        </batch:tasklet>
    </batch:step>
</batch:job> 

Answer 1

让作业参数工作的重要步骤是定义stepscopebean，并确保阅读器是@stepscope组件。

我将尝试以下方法：

首先，确保定义了一个步骤bean。这很适合使用Java配置进行设置：

@Configuration
public class JobFrameworkConfig {  
    @Bean
    public static StepScope scope() {
        return new StepScope();
    }
    // jobRegistry, transactionManager etc...
}

@Component("sourceSelectionReader")
@StepScope // required, also works with @Scope("step")
public class SourceSelectionReaderImpl implements ItemReader<MyThing> {
    private final long myParam;

    // Not lazy, specified param name for the jobParameters
    @Autowired
    public SourceSelectionReaderImpl(@Value("#{jobParameters['myParam']}") final long myParam) {
        this.myParam = myParam;
    }

    // the rest of the reader...
}