java - 使用SAX解析器，如何在java中解析xml文件

Question

是否可以在 SAX 解析器中给出路径表达式？我有一个 XML 文件，其中有一些相同的名称标签，但它们位于不同的元素中。有没有什么方法可以区分它们。这是 XML:

<report id="322077">
        <update>
          <when>1136117311</when>
          <what>nobody@mozilla.org</what>
        </update>
        <update>
          <when>1136117422</when>
          <what>asqueella@gmail.com</what>
        </update>
      </report>
    <report id="322074">
        <update>
          <when>1136117311</when>
          <what>nobody@mozilla.org</what>
        </update>
        <update>
          <when>1136117422</when>
          <what>asqueella@gmail.com</what>
        </update>
      </report>
    <report id="322076">
        <update>
          <when>1136117311</when>
          <what>nobody@mozilla.org</what>
        </update>
        <update>
          <when>1136117422</when>
          <what>asqueella@gmail.com</what>
        </update>
      </report>

Answer 1

String xml= // your xml
DocumentBuilderFactory builderFactory =DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document document = builder.parse(new InputSource(new StringReader(xml)));
String expression="//update"; // See XPath
XPathExpression expr = xpath.compile(expression) ; 
    NodeList nodes  = (NodeList) expr.evaluate(document, XPathConstants.NODESET);
for (int k = 0; k < nodes.getLength(); k++) {
// Do what you want with that