Question

我有一个db to file job。

项目编写者如下：

<beans:bean id="myReportFooterCallback" class="com.myPackage.util.MyReportFooterCallback">
    <beans:property name="delegate" ref="myReportFileItemWriter" />
</beans:bean>

<beans:bean id="myReportFileItemWriter" class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step">
    <beans:property name="resource" value="file:c:\TestData\output_report.dat" /> 

    <beans:property name="lineAggregator">
        <beans:bean class="org.springframework.batch.item.file.transform.FormatterLineAggregator">
            <beans:property name="fieldExtractor">
                <beans:bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor">
                 <beans:property name="names" value="BUSINESS_DATE, FIELD_ONE, FIELD_TWO, FIELD_THREE, FIELD_FOUR, FIELD_FIVE, FIELD_SIX " /> 
                </beans:bean>
            </beans:property>

            <beans:property name="format" value="%-12s%-20s%-20s%-20s%-5s%-5s%-10s" /> 
        </beans:bean>
    </beans:property>

    <beans:property name="footerCallback" ref="myReportFooterCallback" />

</beans:bean>

步骤如下：

<step id="ReportFileGenerator">
        <tasklet transaction-manager="jobRepository-transactionManager">
            <chunk reader="ReportFileItemReader" writer="myReportFooterCallback"  commit-interval="1000"/>
        </tasklet>
</step>

MyReportFooterCallback类如下：

public class MyReportFooterCallback implements ItemWriter<MyReportBean>, FlatFileFooterCallback {

private ItemWriter<MyReportBean> delegate;

private double totalDebitAmount = 0.0;
private double totalCreditAmount = 0.0;
private int totalDebit = 0;
private int totalCredit = 0;

public void write(final List<? extends MyReportBean> items) throws Exception {

    System.out.println("in write method!");

    int chunkDebitCount = 0;
    int chunkCreditCount = 0;
    double chunkDebitTot = 0.0;
    double chunkCreditTot = 0.0;

    for (MyReportBeanitem : items) {
        if (item.getIndicator().equalsIgnoreCase("Debit")) {
            // its a debit
            chunkDebitCount = chunkDebitCount + 1;
            chunkDebitTot = chunkDebitTot + Double.parseDouble(item.getTRANS_AMT());

        } else {
            // its a credit
            chunkCreditCount = chunkCreditCount + 1;
            chunkCreditTot = chunkCreditTot + Double.parseDouble(item.getTRANS_AMT());

        }
    }

    this.delegate.write(items);

    this.totalDebit = this.totalDebit + chunkDebitCount;
    this.totalDebitAmount = this.totalDebitAmount + chunkDebitTot;
    this.totalCredit = this.totalCredit + chunkCreditCount;
    this.totalCreditAmount = this.totalCreditAmount + chunkCreditTot;
}


public void writeFooter(final Writer writer) throws IOException {

    writer.write("\n");
    writer.write("\n");
    writer.write("Total Debits Processed: " + this.totalDebit);
    writer.write("\n");
    writer.write("Total Debit Amount: " + this.totalDebitAmount);
    writer.write("\n");
    writer.write("\n");
    writer.write("Total Credits Processed: " + this.totalCredit);
    writer.write("\n");
    writer.write("Total Credit Amount: " + this.totalCreditAmount);
}


public void setDelegate(final ItemWriter<MyReportBean> delegate) {
    this.delegate = delegate;
}

}

但是，上面的代码没有按预期工作：

1）使用七列生成文件output_report.dat。但是，页脚不显示总值。所有四个值都是0（计数和总数）。

我错过了什么？

2）另外，是否可以将列名添加到每列的顶部？

3）有任何方法可以将页码添加到输出报告中吗？

感谢阅读！

Answer 1

使用类似示例的快速尝试对我来说没有问题*（即使没有步骤范围）

1）您是否尝试过JUnit测试以确定它有效？下一步是调试/记录

2）确定，也存在HeaderCallback

3）没有开箱即用，但实现它不应该太难，使用totalCount，除以pagesize，如果结果是整数则打印项目

（*）您的示例似乎不完整，我必须将myReportFileItemWriter注册为Stream

将页眉和页脚写入输出文件，以便将数据库写入文件作业

1 个答案: