Spring批处理分区：ItemReader Bean在@value（“#{stepexecutioncontext[fromId]}”）读取中存在问题

Question

spring batch的新版本，并尝试为大量数据输入实现分区。我已经检查了下面的解决方案，这些解决方案与我的问题相似，但不能解决问题。

Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 0): Property or field 'stepExecutionContext' cannot be found on object of type 'org.springframework.beans.factory.config.BeanExpressionContext' - maybe not public?
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:224)
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:94)
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:81)
    at org.springframework.expression.spel.ast.CompoundExpression.getValueRef(CompoundExpression.java:51)
    at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:87)
    at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:120)
    at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:242)
    at org.springframework.context.expression.StandardBeanExpressionResolver.evaluate(StandardBeanExpressionResolver.java:161)
    ... 19 more

@Configuration
public class ProfileJobItemReader{

    @Value("#{stepExecutionContext[fromId]}")
    private int fromId;

    @Bean(name = "profileMongoItemReader")
    @StepScope
    public ItemReader<ProfileCollection> profileMongoItemReader()
            throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {

        System.out.println(fromId);
    }

}

<bean id="profileItemProcessor" class="...........ProfileProcessor" scope="step" />
<bean id="profileItemWriter" class="...........ProfileWriter" scope="step" />

.............

<bean id="rangePartitioner" class="...........ProfilePartitioner" />

<batch:job id="profileJob">
    <batch:step id="masterStep">
        <partition step="profileMainStep" partitioner="rangePartitioner">
            <handler grid-size="100" task-executor="taskExecutor" />
        </partition>
    </batch:step>
</batch:job>

<batch:step id="profileMainStep">
    <batch:tasklet task-executor="profileTaskExecutor" throttle-limit="30">
        <batch:chunk reader="profileMongoItemReader" processor="profileItemProcessor"
            writer="profileItemWriter" commit-interval="${profileCommitInterval}" />
    </batch:tasklet>
</batch:step>

@Value("#{stepExecutionContext[fromId]}")

public class ProfileProcessor implements ItemProcessor<ProfileCollection, ProfileCollection> {

    @Value("#{stepExecutionContext[name]}")
    private String threadName;

    @Override
    public ProfileCollection process(ProfileCollection item) throws Exception {
        System.out.println(threadName);

Answer 1

问题是阅读器中的@configuration注释。在作业开始前加载配置类。

只有在启动一个步骤之后，您才会获得stepexecutioncontext。处理器类获得StepExecutionContext，因为它没有Component/Configuration注释。