接下来说的第二种方式是用RootElement这个类来解析的,RootElement 内置了defaultHandler的子类,
RootElement 源码如下:
public class RootElement extends Element { final Handler handler = new Handler(); public RootElement(String uri, String localName) { super(null, uri, localName, 0); } public RootElement(String localName) { this("", localName); } public ContentHandler getContentHandler() { return this.handler; } class Handler extends DefaultHandler { Locator locator; int depth = -1; Element current = null; StringBuilder bodyBuilder = null; @Override public void setdocumentLocator(Locator locator) { this.locator = locator; } @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { int depth = ++this.depth; if (depth == 0) { // This is the root element. startRoot(uri, localName, attributes); return; } // Prohibit mixed text and elements. if (bodyBuilder != null) { throw new BadXmlException("Encountered mixed content" + " within text element named " + current + ".", locator); } // If we're one level below the current element. if (depth == current.depth + 1) { // Look for a child to push onto the stack. Children children = current.children; if (children != null) { Element child = children.get(uri, localName); if (child != null) { start(child, attributes); } } } } void startRoot(String uri, String localName, Attributes attributes) throws SAXException { Element root = RootElement.this; if (root.uri.compareTo(uri) != 0 || root.localName.compareTo(localName) != 0) { throw new BadXmlException("Root element name does" + " not match. Expected: " + root + ", Got: " + Element.toString(uri, localName), locator); } start(root, attributes); } void start(Element e, Attributes attributes) { // Push element onto the stack. this.current = e; if (e.startElementListener != null) { e.startElementListener.start(attributes); } if (e.endTextElementListener != null) { this.bodyBuilder = new StringBuilder(); } e.resetRequiredChildren(); e.visited = true; } @Override public void characters(char[] buffer, int start, int length) throws SAXException { if (bodyBuilder != null) { bodyBuilder.append(buffer, start, length); } } @Override public void endElement(String uri, String localName, String qName) throws SAXException { Element current = this.current; // If we've ended the current element... if (depth == current.depth) { current.checkRequiredChildren(locator); // Invoke end element listener. if (current.endElementListener != null) { current.endElementListener.end(); } // Invoke end text element listener. if (bodyBuilder != null) { String body = bodyBuilder.toString(); bodyBuilder = null; // We can assume that this listener is present. current.endTextElementListener.end(body); } // Pop element off the stack. this.current = current.parent; } depth--; } } }以上是RootElement类得源码,从源码可以看出,它只是将defaultHandler简单的处理一下。
具体应用可以参照我写的测试源码
private String saxParseSecond(){ //读取src下xml文件 InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("saxTest.xml"); SAXParserFactory factory = SAXParserFactory.newInstance(); try { SAXParser parse = factory.newSAXParser(); XMLReader reader = parse.getXMLReader(); reader.setContentHandler(getRootElement().getContentHandler()); reader.parse(new InputSource(inputStream)); } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return result; } private RootElement getRootElement(){ RootElement rootElement = new RootElement("classes"); Element groupElement = rootElement.getChild("group"); // 读到元素开始位置时触发,如读到时 groupElement.setStartElementListener(new StartElementListener() { @Override public void start(Attributes attributes) { // Log.i("TEST", "start"); String groupName = attributes.getValue("name"); String groupNum = attributes.getValue("num"); result = result+"groupName ="+groupName+"groupNum = "+groupNum+"n"; } }); //读到元素结束位置时触发,如读到 时 groupElement.setEndElementListener(new EndElementListener() { @Override public void end() { } }); Element personElement = groupElement.getChild("person"); //读取标签触发 personElement.setStartElementListener(new StartElementListener() { @Override public void start(Attributes attributes) { String personName = attributes.getValue("name"); String age = attributes.getValue("age"); result = result+"personName ="+personName+"age = "+age+"n"; } }); //读取 标签触发 personElement.setEndElementListener(new EndElementListener() { @Override public void end() { } }); Element chinese = personElement.getChild("chinese"); // chinese.setTextElementListener(new TextElementListener() { // // @Override // public void end(String body) { // // TODO Auto-generated method stub // // } // // @Override // public void start(Attributes attributes) { // // TODO Auto-generated method stub // // } // }); // 读到文本的末尾时触发,这里的body即为文本的内容部分 chinese.setEndTextElementListener(new EndTextElementListener() { @Override public void end(String body) { Pattern p = Pattern.compile("\s*|t|r|n"); Matcher m = p.matcher(body); body = m.replaceAll(""); result = result+"chinese ="+body; } }); Element english = personElement.getChild("english"); english.setEndTextElementListener(new EndTextElementListener() { @Override public void end(String body) { Pattern p = Pattern.compile("\s*|t|r|n"); Matcher m = p.matcher(body); body = m.replaceAll(""); result = result+"english ="+body+"n"; } }); return rootElement; }我们都知道通过SAXParser对象解析xml的方式,这里我们又从代码中看到了利用另一个对象XMLReader进行解析,那么两者到底有什么联系和区别呢?
其实SAXParser是在SAX 1.0 定义的,而XMLReader则是在2.0中才开始出现的。你可以认为XMLReader的出现是为了替代SAXParser解析的,两者本质上干的事情是一样的,只不过XMLReader的功能更加的强悍而已。
关于XMLReader的获取方式,除了通过SAXParser的getXMLReader方法获得之外,我们还可以通过以下两种方式。
XMLReader parser=XMLReaderFactory.createXMLReader(); (1)XMLReader parser=XMLReaderFactory.createXMLReader(String className); (2)
以上就是 android sax解析xml文件(二)的内容,更多相关内容请关注PHP中文网(www.kaotop.com)!



