无法使用 Spring 批处理将两个数据库表数据写入 XML 文件

Question

越来越喜欢现在的Spring Batch了。我正在开发 Spring Batch 代码，它读取两个表数据（Customer 和 Employee）并写入 XML 文件。我开发了代码，当运行我的 main() 程序时，我看到空文件即将到来。为什么？

customers.xml

<?xml version="1.0" encoding="UTF-8"?><customers></customers>

下面我开发的代码供参考： Customer.java

public class Customer implements Serializable{
    private static final long serialVersionUID = 1L;

    private Integer customerNumber;
    private String customerName;
    private String contactLastName;
    private String contactFirstName;
    private String phone;
    private String addressLine1;
    private String addressLine2;
    private String city;
    private String state;
    private String postalCode;
    private String country;
    private Integer salesRepEmployeeNumber;
    private Double creditLimit;
    // setters and getters
}

Employee.java

public class Employee implements Serializable{
    private static final long serialVersionUID = 1L;

    private Integer employeeNumber;
    private String lastName;
    private String firstName;
    private String extension;
    private String email;
    private String officeCode;
    private Integer reportsTo;
    private String jobTitle;
    // setters and getters
}

xml-jdbc-复合项-reader-job.xml

<?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"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd">

    <import resource="classpath:context-datasource.xml" />

    <!-- JobRepository and JobLauncher are configuration/setup classes -->
    <bean id="jobRepository" class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean" />

    <bean id="jobLauncher"  class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
        <property name="jobRepository" ref="jobRepository" />
    </bean>


    <!-- Step will need a transaction manager -->
    <bean id="transactionManager"
        class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />


    <!-- =========================================================== -->    
    <job id="compositeJdbcReaderJob" xmlns="http://www.springframework.org/schema/batch">
        <step id="compositeJdbcReaderStep" next="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemReader1" writer="itemWriter1" commit-interval="5" />
            </tasklet>
        </step>

        <step id="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemWriter2" writer="itemWriter2" commit-interval="5" />
            </tasklet>
        </step>
    </job>



    <!-- ========== ItemReader =============== -->
    <bean id="itemReader1" class="org.springframework.batch.item.database.JdbcCursorItemReader">
        <property name="dataSource" ref="dataSource" />

        <property name="saveState" value="true" />

        <property name="sql">
            <value>
                <![CDATA[ ${select.sql.customers} ]]>
            </value>
        </property>
        <property name="rowMapper">
            <bean class="com.common.batch.mapper.CustomerMapper" />
        </property>
    </bean>


    <bean id="itemReader2" class="org.springframework.batch.item.database.JdbcCursorItemReader">
        <property name="dataSource" ref="dataSource" />

        <property name="saveState" value="true" />

        <property name="sql">
            <value>
                <![CDATA[ ${select.sql.employees} ]]>
            </value>
        </property>
        <property name="rowMapper">
            <bean class="com.common.batch.mapper.EmployeeMapper" />
        </property>
    </bean>


    <!-- ItemWritter -->
    <bean id="itemWriter1" class="org.springframework.batch.item.xml.StaxEventItemWriter">
        <property name="resource" value="file:xml/customers.xml" />

        <property name="marshaller" ref="customerUnmarshaller" />

        <property name="rootTagName" value="customers" />
    </bean>

    <bean id="itemWriter2" class="org.springframework.batch.item.xml.StaxEventItemWriter">
        <property name="resource" value="file:xml/customers.xml" />

        <property name="marshaller" ref="employeeUnmarshaller" />

        <property name="rootTagName" value="employees" />
    </bean>

    <!-- ======= Employee Unmarshaller ======== -->
    <bean id="employeeUnmarshaller" class="org.springframework.oxm.xstream.XStreamMarshaller">
        <property name="aliases">
            <util:map id="aliases">
                <entry key="employee" value="com.common.batch.model.Employee" />
            </util:map>
        </property>
    </bean>

        <!-- ======= Customer Unmarshaller ======== -->
    <bean id="customerUnmarshaller" class="org.springframework.oxm.xstream.XStreamMarshaller">
        <property name="aliases">
            <util:map id="aliases">
                <entry key="customer" value="com.common.batch.model.Customer" />
            </util:map>
        </property>
    </bean>


    <bean id="itemCustomerProcessor" class="com.common.batch.processor.CustomerProcessor" />
    <bean id="itemEmployeeProcessor" class="com.common.batch.processor.EmployeeProcessor" />
</beans>

CompositeXMLMain.java

public class CompositeXMLMain {
    @SuppressWarnings("resource")
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("composite/xml-jdbc-composite-item-reader-job.xml");

        JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");
        Job job = (Job) context.getBean("compositeJdbcReaderJob");

        JobExecution execution;
        try {
            execution = jobLauncher.run(job, new JobParameters());
            System.out.println("Job Exit Status : "+ execution.getStatus());

        } catch (JobExecutionAlreadyRunningException | JobRestartException
                | JobInstanceAlreadyCompleteException | JobParametersInvalidException e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
        System.out.println("Done !!");
    }
}

Answer 1

我犯了一个小错误，为了解决这个问题，只需要将 itemWriter2 更改为 itemReader2

 <job id="compositeJdbcReaderJob" xmlns="http://www.springframework.org/schema/batch">
        <step id="compositeJdbcReaderStep" next="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemReader1" writer="itemWriter1" commit-interval="5" />
            </tasklet>
        </step>

        <step id="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemWriter2" writer="itemWriter2" commit-interval="5" />
            </tasklet>
        </step>
    </job>

到

 <job id="compositeJdbcReaderJob" xmlns="http://www.springframework.org/schema/batch">
        <step id="compositeJdbcReaderStep" next="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemReader1" writer="itemWriter1" commit-interval="5" />
            </tasklet>
        </step>

        <step id="compositeJdbcReaderStep2">
            <tasklet>
                <chunk reader="itemReader2" writer="itemWriter2" commit-interval="5" />
            </tasklet>
        </step>
    </job>

无法使用 Spring 批处理将两个数据库表数据写入 XML 文件

unable to write two database tables data to XML file using Spring Batch

java

spring-batch

xstream

spring-batch-admin