Question

我能够使用带有根标记的StaxEventItemWriter从数据库读取数据并编写XML。如何在XML文件中添加页眉和页脚？

@Bean(destroyMethod="")
    ItemWriter<BatchRequest> databaseXmlItemWriter() {
        StaxEventItemWriter<BatchRequest> xmlFileWriter = new StaxEventItemWriter<>();        

        xmlFileWriter.setResource(new FileSystemResource(System.getProperty("outputFile")));
        xmlFileWriter.setRootTagName("employee");

        Jaxb2Marshaller employeeMarshaller = new Jaxb2Marshaller();
        employeeMarshaller.setClassesToBeBound(BatchRequest.class);
        xmlFileWriter.setMarshaller(employeeMarshaller);
        return xmlFileWriter;
    }

Answer 1

您可以使用org.springframework.batch.item.xml.StaxEventItemWriter#setHeaderCallback和org.springframework.batch.item.xml.StaxEventItemWriter#setFooterCallback通过org.springframework.batch.item.xml.StaxWriterCallback将标题/页脚写入XML文件。

Answer 2

正如@Mahmoud 在他的回答中所说，我们可以使用 StaxEventItemWriter's setHeaderCallback() 和 setFooterCallback() 来注册我们的页眉和页脚代码。

以下是给您的代码片段：

@StepScope
@Bean(name = "staxTransactionWriter")
public StaxEventItemWriter<BatchRequest> staxTransactionItemWriter(@Value("#{jobParameters['file.path']}") String path) {
    Resource exportFileResource = new FileSystemResource(path);

    Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
    marshaller.setSupportJaxbElementClass(true);
    marshaller.setClassesToBeBound(BatchRequest.class);
    
     StaxEventItemReaderBuilder<BatchRequest> writer = new StaxEventItemReaderBuilder<BatchRequest>();
     writer.setName("employeeWriter");
     writer.setVersion("1.0");
     writer.setResource(exportFileResource);
     writer.setMarshaller(marshaller);
     writer.setRootTagName("employee");
     writer.setHeaderCallback(getXmlHeaderCallBack());
     writer.setFooterCallback(getXmlFooterCallBack());
     writer.setShouldDeleteIfEmpty(true);
     return writer;
}

@Bean
OmegaXmlHeaderCallBack getXmlHeaderCallBack(){
    return new XmlHeaderCallBack();
}

@Bean
OmegaXmlFooterCallBack getXmlFooterCallBack(){
    return new XmlFooterCallBack();
}

下面的代码创建了一个自定义的页眉和页脚类，它扩展了 StaxWriterCallback：

@Slf4j
public class XmlFooterCallBack implements StaxWriterCallback {

    @Override
    public void write(XMLEventWriter writer) {
        XMLEventFactory factory = XMLEventFactory.newInstance();
        try {
            writer.add(factory.createEndElement("", "", "record"));
        } catch (XMLStreamException e) {
            log.error("Error writing OMEGA XML Footer: {}", e.getMessage());
            throw new OmegaXmlHeaderWriterException(e.getMessage());
        }
    }
}

@Slf4j
public class XmlHeaderCallBack implements StaxWriterCallback {
    
    public XmlHeaderCallBack() {
        super();
    }

    @Override
    public void write(XMLEventWriter writer) {
        XMLEventFactory factory = XMLEventFactory.newInstance();
        try {
            writer.add(factory.createStartElement("", "", "fileInformation"));

            writer.add(factory.createStartElement("", "", "sender"));
            writer.add(factory.createCharacters("SENDER ID"));
            writer.add(factory.createEndElement("", "", "sender"));


            writer.add(factory.createStartElement("", "", "timestamp"));
            writer.add(factory.createCharacters("CURRENT DATE_TIME"));
            writer.add(factory.createEndElement("", "", "timestamp"));

            writer.add(factory.createStartElement("", "", "environment"));
            writer.add(factory.createCharacters("LOCAL"));
            writer.add(factory.createEndElement("", "", "environment"));

            writer.add(factory.createStartElement("", "", "version"));
            writer.add(factory.createCharacters("1.2.3"));
            writer.add(factory.createEndElement("", "", "version"));
            
            writer.add(factory.createEndElement("", "", "fileInformation"));
            
            writer.add(factory.createStartElement("", "", "record"));
            
        } catch (XMLStreamException e) {
            log.error("Error writing XML Header: {}", e.getMessage());
            throw new CustomXmlHeaderWriterException(e.getMessage());
        }
    }
}

<块引用>

标题看起来像

    <fileInformation>
      <sender>SENDER ID</sender>
      <timestamp>CURRENT DATE_TIME</timestamp>
      <environment>LOCAL</environment>
      <version>1.2.3</version>
   </fileInformation>
   <record>

<块引用>

页脚的结束标记为 record

</record>

春季批处理如何使用页眉和页脚编写XML文件

2 个答案: