XML节点至字符串转换为大型XML [英] XML Node to String Conversion for Large Sized XML

问题描述

到现在为止我所用的 DOMSource的以XML文件转换为字符串，在我的Andr​​oid应用程序。

Till now I was using DOMSource to transform the XML file into string, in my Android App.

这里是我的code

public  String convertElementToString (Node element) throws TransformerConfigurationException, TransformerFactoryConfigurationError
{
      Transformer transformer = TransformerFactory.newInstance().newTransformer();
      transformer.setOutputProperty(OutputKeys.INDENT, "yes");

       //initialize StreamResult with File object to save to file
      StreamResult result = new StreamResult(new StringWriter());
      DOMSource source = new DOMSource(element);

      try {
          transformer.transform(source, result);  
      } 
      catch (TransformerException e) {
          Log.e("CONVERT_ELEMENT_TO_STRING", "converting element to string failed. Aborting", e);
      }

      String xmlString = result.getWriter().toString();
      xmlString = xmlString.replace("<?xml version=\"1.0\" encoding=\"UTF-8\"?>", "");
      xmlString = xmlString.replace("\n", "");
      return xmlString; 
}

本是工作的罚款对小XML 文件。

但是为大型XML 这code开始的抛出的OutOfMemoryError

But for large sized xml this code started throwing OutOfMemoryError.

这可能是它背后的原因如何纠正这个问题？

What may be the reason behind it and how to rectify this problem?

推荐答案

第一关：如果您只需要XML作为字符串，并且不使用节点为别的，你应该使用的StAX（流API为XML ），而不是作为具有低得多的内存占用。你会在 javax.xml.stream中封装标准库找到StAX的。

First off: if you just need the XML as a string, and aren't using the Node for anything else, you should use StAX (Streaming API for XML) instead, as that has a much lower memory footprint. You'll find StAX in the javax.xml.stream package of the standard libraries.

一个改进到当前code将更改行

One improvement to your current code would be to change the line

transformer.setOutputProperty(OutputKeys.INDENT, "yes");

到

transformer.setOutputProperty(OutputKeys.INDENT, "no");

既然你在方法的啦去除换行，这不是非常有用索取更多缩进输出。这是一个很小的事情，但是如果有很多的标签（因此，换行和空格进行缩进）在你的XML可能会降低内存需求了一下。

Since you're stripping newlines anyway at the end of the method, it's not very useful to request additional indentation in the output. It's a small thing, but might reduce your memory requirements a bit if there are a lot of tags (hence, newlines and whitespace for indentation) in your XML.

这篇关于XML节点至字符串转换为大型XML的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！