Writing header and footer to the output file for a database to file job

I have a db to file job.

The item writer is as below:

Code:

---

<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>

---

And the step is as below:

Code:

---

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

---

The class MyReportFooterCallback is as below:

Code:

---

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;
    }

    }

---

However, above code is not working as expected:

1) The file output_report.dat gets generated with the seven columns.However, the footer doesn't show the total values. All four values are 0 (the count and the total).

Total Debits Processed: 0
Total Debit Amount: 0.0

Total Credits Processed: 0
Total Credit Amount: 0.0

What am I missing ?

2) Also, is it possible to add the column names to the top of each column ?
3) Any way to add page numbers to the output report ?

Thanks for reading!