Create XML file with large number of nodes (10 million)

I tried to create file for test with 10 000 000 nodes like:

    DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
            .newInstance();
    DocumentBuilder documentBuilder = documentBuilderFactory
            .newDocumentBuilder();
    Document document = documentBuilder.newDocument();
    Element rootElement = document.createElement("root");
    document.appendChild(rootElement);
    for (int i = 1; i <= 10000000; i++) {
        Element em = document.createElement("ch");
        em.appendChild(document.createTextNode("ch_data"));
        rootElement.appendChild(em);
    }
    TransformerFactory transform开发者_C百科erFactory = TransformerFactory
            .newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    DOMSource source = new DOMSource(document);
    StreamResult result = new StreamResult(new File("c:/file1.xml"));
    transformer.transform(source, result);

But received error:

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
    at   com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.
createElement(CoreDocumentImpl.java:620)
    at main.CreatXMLFile.main(CreatXMLFile.java:27)

Does there exist another library for create XML files with more than 10 000 000 nodes in Java?

For trivial files like that: consider writing the xml file without using any DOM or StAX:

writeToFile("<root>\n");
for (int i = 0; i < 10000000; i++) {
  writeToFile("<ch>" + getData(i) + "</ch>\n");
}
writeToFile("</root>\n");

That's all - you just need a method that writes a String to a file. And a method to get your textual data.

Use StAX to write the XML as a stream, so that the entire document doesn't need to reside in memory.

You could try using SAX parser or JDOM

DOM parser creates an internal tree based on the hierarchical structure of the XML data.In SAX's event-based system, the parser doesn't create any internal representation of the document. Instead, the parser calls handler functions when certain events (defined by the SAX specification) take place. These events include the start and end of the document, finding a text node, finding child elements, and hitting a malformed element.

If you need to parse and process huge XML documents, SAX implementations offer more benefits over DOM-based ones.

You might try to increase the memory allocated for the JVM.

But why do you need to have the whole file in memory? If there is not a really good reason for that, you shouldn't do it.

you can try by increasing memory size for JVM.

There are several ways to create xml file in java.you can find some example in the following link.

http://www.javazoom.net/services/newsletter/xmlgeneration.html