拆分大型XML FIles Java(StAX)

时间:2017-03-30 10:58:22

标签: java xml stax filesplitting

我正在使用GitHub中的代码https://github.com/koen-serneels/blog/tree/master/BigXmlTest/src/main/java/be/error/bigxmltest来分割大型XML文件(6GB)。我首先提供了用于理解程序的基本XML文件。程序输出分割的每个文件的标题。我现在也试图为每个文件添加一个页脚元素并遇到一些困难,任何有关如何进行此操作的建议或建议都会很棒。

我已将页脚添加到架构中并编写代码以在“openOutputFileAndWriteHeader()”方法中添加页脚。但是,这会在内容元素中添加页脚。如下所示:

private XMLEventWriter openOutputFileAndWriteHeader(int fileNumber) throws Exception
{

    XMLEventFactory xmlEventFactory = XMLEventFactory.newInstance();
    XMLOutputFactory xmlOutputFactory = XMLOutputFactory.newInstance();
    xmlOutputFactory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, true);
    XMLEventWriter writer = xmlOutputFactory.createXMLEventWriter(new FileOutputStream(new File("C:\\Users\\thamm\\Desktop\\SplitFiles\\File_" + fileNumber + ".xml")));

    writer.setDefaultNamespace(DOCUMENT_NS);
    writer.add(xmlEventFactory.createStartDocument());

    writer.add(xmlEventFactory.createStartElement(new QName(DOCUMENT_NS, ROOT_ELEMENT), null, null));

    HeaderType header = objectFactory.createHeaderType();
    header.setSomeHeaderElement("List of Employees");
    marshaller.marshal(new JAXBElement<HeaderType>(new QName(DOCUMENT_NS, HEADER_ELEMENT, ""), HeaderType.class, 
                    HeaderType.class, header), writer);

    writer.add(new StartElementEvent(new QName(DOCUMENT_NS, CONTENT_ELEMENT)));

    FooterType footer = objectFactory.createFooterType();
    footer.setSomeFooterElement("Footer");
    marshaller.marshal(new JAXBElement<FooterType>(new QName(DOCUMENT_NS, FOOTER_ELEMENT,""), FooterType.class, 
                      FooterType.class, footer), writer);

    return writer;
}

输出:

<?xml version='1.0' encoding='UTF-8'?>
<BigXmlTest xmlns="http://www.sidero.ie/bigxmltest">
    <Header>
        <SomeHeaderElement>List of Employees</SomeHeaderElement>
    </Header>
    <Content>
        <Footer>
            <SomeFooterElement>Footer</SomeFooterElement>
        </Footer>
        <Data>Data4</Data>
        <Data>Data5</Data>
        <Data>Data6</Data>
    </Content>
</BigXmlTest>

1 个答案:

答案 0 :(得分:0)

方法名称openOutputFileAndWriteHeader暗示它将创建文件。它不适合页脚。

在第74行的BigXmlTestIteratorApi.java中,您可以看到代码:

xmlEventWriter.close(); // Also closes any open Element(s) and the document
xmlEventWriter = openOutputFileAndWriteHeader(++fileNumber); // Continue with next file
dataRepetitions = 0;

要添加页脚,您需要在关闭文件前添加

writeFooter(footer);
xmlEventWriter.close(); 
xmlEventWriter = openOutputFileAndWriteHeader(++fileNumber);
dataRepetitions = 0;

请注意,为每个文件创建FooterType的实例可能是多余的。它可以在循环外部创建,例如在60行