Spring 批处理 MultiResourceItemWriter 无法正确地将数据写入文件

Question

这是我的 SpringBatch maven 依赖项：

    <dependency>
        <groupId>org.springframework.batch</groupId>
        <artifactId>spring-batch-core</artifactId>
        <version>2.2.0.RELEASE</version>
    </dependency>

下面是我的job.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:batch="http://www.springframework.org/schema/batch" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/batch
        http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">

    <import resource="../config/launch-context.xml" />

    <bean id="inputFileForMultiResource" class="org.springframework.core.io.FileSystemResource" scope="step">
        <constructor-arg value="src/main/resources/files/customerInputValidation.txt"/>
    </bean>

    <bean id="outputFileForMultiResource" class="org.springframework.core.io.FileSystemResource" scope="step">
        <constructor-arg value="src/main/resources/files/xml/customerOutput.xml"/>
    </bean>

    <bean id="readerForMultiResource" class="org.springframework.batch.item.file.FlatFileItemReader">
        <property name="resource" ref="inputFileForMultiResource" />
        <property name="lineMapper">
            <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
            <property name="lineTokenizer">
                <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
                    <property name="names" value="firstName,middleInitial,lastName,address,city,state,zip" />
                    <property name="delimiter" value="," />
                </bean>
            </property>
            <property name="fieldSetMapper">
                <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
                    <property name="prototypeBeanName" value="customer5TO" />
                </bean>
            </property>
            </bean>
        </property>
    </bean>
    <bean id="customer5TO" class="net.gsd.group.spring.batch.tutorial.to.Customer5TO"></bean>

    <bean id="xmlOutputWriter" class="org.springframework.batch.item.xml.StaxEventItemWriter">
        <property name="resource" ref="outputFileForMultiResource" />
        <property name="marshaller" ref="customerMarshallerJMSJob" />
        <property name="rootTagName" value="customers" />
    </bean>
    <bean id="customerMarshallerJMSJob" class="org.springframework.oxm.xstream.XStreamMarshaller">
        <property name="aliases">
            <map>
                <entry key="customer" value="net.gsd.group.spring.batch.tutorial.to.Customer5TO"></entry>
            </map>
        </property>
    </bean>
    <bean id="multiResourceItemWriter" class="org.springframework.batch.item.file.MultiResourceItemWriter">
        <property name="resource" ref="customerOutputXmlFile"/>
        <property name="delegate" ref="xmlOutputWriter"/>
        <property name="itemCountLimitPerResource" value="3"/>
        <property name="resourceSuffixCreator" ref="suffix"/>
    </bean>

    <bean id="suffix" class="net.gsd.group.spring.batch.tutorial.util.CustomerOutputFileSuffixCreator"></bean>

    <batch:step id="multiResourceWriterParentStep">
        <batch:tasklet>
            <batch:chunk 
                reader="readerForMultiResource"
                writer="multiResourceItemWriter"
                commit-interval="3">
            </batch:chunk>
        </batch:tasklet>
    </batch:step>

    <batch:job id="multiResourceWriterJob">
        <batch:step id="multiResourceStep" parent="multiResourceWriterParentStep"/>
    </batch:job>
</beans>

基本上我有一个输入文件和多个输出文件。我从输入文件（包含 10 行）中读取数据，我想将其以 3 个为一组写入多个输出文件（在我的例子中，将有 4 个文件 3/3/3/1）。对于每个块，将有一个文件。作业工作正常，但输出文件的内容是错误的。每个文件都包含在当前块中读取的最后一个元素。

假设第一个块读取 A、B 和 C。当将此块写入文件时，仅写入 C 并写入 3 次。

根据我的测试，它仅在块提交间隔为 1 时才能正常工作。

这是正确的行为吗？我做错了什么？

提前致谢

Answer 1

您的 customer5TO bean 应该具有范围 prototype。目前它是一个单例，因此 bean 属性将始终被最后一项覆盖。

Spring 批处理 MultiResourceItemWriter 无法正确地将数据写入文件

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