Java中如何将xml解析为字符串呢?

xml解析为字符串的实现思路
     1. 使用 DocumentBuilderFactory对象,定义实例
     2. 使用InputSource获取xml 
     3. 使用DocumentBuilderFactory对象中的parse方法
           将xml转换为字符串

public static Document loadXMLFromString(String xml) throws Exception
{
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    InputSource is = new InputSource(new StringReader(xml));
    return builder.parse(is);
}