dom解析占用內存大（我這邊需要解析各種各樣的kml文件，有時4-5M的kml文件使用dom解析很多手機就內存溢出了），也需要引入第三方庫，所以使用相對于節省內存很多、不需引入其他庫的sax解析就是很好的選擇了。因為sax解析比較復雜的xml文件特別麻煩，所以整理了一個簡化android sax解析的工具。

　　實現思路：和Android Touch事件傳遞機制一樣，把需要子解析器解析的節點往下傳遞。

　　如果有進一步簡化的方法，歡迎交流！email:csqwyyx@163.com。

　　示例程序：https://github.com/John-Chen/EasySaxParser

?

　　簡化工具SaxParser：

public abstract class SaxParser {protected String curQName;protected StringBuilder curValue = new StringBuilder();protected SaxParser saxParser;protected String saxParserQName;/*** 需要生成子SaxParser的節點名稱*/protected HashSet<String> childParserQNames;public SaxParser() {}public SaxParser(HashSet<String> childParserQNames) {this.childParserQNames = childParserQNames;}protected void startElement(String uri, String localName, String qName, Attributes attributes) {if(qName == null){return;}if(saxParser != null){saxParser.startElement(uri, qName, qName, attributes);}else if(childParserQNames != null && childParserQNames.contains(qName)){this.saxParser = dispatchTo(qName, attributes);if(this.saxParser != null){this.saxParserQName = qName;saxParser.parserStart(attributes);}}else{curQName = qName;if(curValue.length() > 0){curValue.delete(0, curValue.length());}}}protected void endElement(String uri, String localName, String qName) {if(qName == null){return;}if(qName.equals(saxParserQName)){if(saxParser != null){saxParser.parserEnd();}saxParser = null;saxParserQName = null;}else if(saxParser != null){saxParser.endElement(uri, qName, qName);}else{parserElementEnd(qName, curValue.toString());curQName = null;if(curValue.length() > 0){curValue.delete(0, curValue.length());}}}protected void characters(char[] ch, int start, int length) {if(saxParser != null){saxParser.characters(ch, start, length);}else{String data = new String(ch, start, length);if(data.length() > 0 && curQName != null){curValue.append(data);}}}/*** 開始解析一個輸入流* @param is 文件輸入流* @param rootParserQName 解析的文件根節點* @param rootParser 根解析器*/public static void start(InputStream is,final String rootParserQName,final SaxParser rootParser){try {SAXParser parser = SAXParserFactory.newInstance().newSAXParser();parser.parse(is, new DefaultHandler(){@Overridepublic void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {if(qName == null){return;}if(rootParser != null){rootParser.startElement(uri, qName, qName, attributes);}else if(qName.equals(rootParserQName)){rootParser.parserStart(attributes);}}@Overridepublic void characters(char[] ch, int start, int length) throws SAXException {if(rootParser != null){rootParser.characters(ch, start, length);}}@Overridepublic void endElement(String uri, String localName, String qName) throws SAXException {if(qName == null){return;}if(qName.contains(rootParserQName)){if(rootParser != null){rootParser.parserEnd();}}else if(rootParser != null){rootParser.endElement(uri, qName, qName);}}});} catch (Exception e) {e.printStackTrace();}}/*** 節點解析開始*/public abstract void parserStart(Attributes attributes);/*** 一個子節點解析結束* @param value characters獲得的值*/public abstract void parserElementEnd(String qName, String value);/*** 解析事件需要向下傳遞，返回需要傳遞的子SaxParser*/public abstract SaxParser dispatchTo(String qName, Attributes attributes);/*** 節點解析結束*/public abstract void parserEnd();}

?

需要解析的xml文件test.xml:

<?xml version="1.0" encoding="UTF-8"?><kml xmlns:gx="http://www.google.com/kml/ext/2.2"><Document id="123"><description>abc</description><author>csq</author><ExtendedData><Data name="TrackId"><value>293156</value></Data><Data name="TrackTypeId"><value>8</value></Data></ExtendedData><Placemark><name>深圳灣公園</name><TimeStamp><when>2015-03-21T10:00:13Z</when></TimeStamp><Point><coordinates>113.93946,22.48955,9.0</coordinates></Point></Placemark></Document></kml>

　　　

開始解析：

根節點kml，根節點解析器KmlParser

SaxParser.start(getAssets().open("test.kml"), "kml", new Kml.KmlParser(kml));

?

部分節點解析實現：

public static class KmlParser extends SaxParser {private Kml kml;public KmlParser(Kml kml) {super(new HashSet<String>());this.kml = kml;childParserQNames.add("Document");}@Overridepublic void parserStart(Attributes attributes) {}@Overridepublic void parserElementEnd(String qName, String value) {}@Overridepublic SaxParser dispatchTo(String qName, Attributes attributes) {if(qName.equals("Document")){return new Document.DocumentParser(kml);}return null;}@Overridepublic void parserEnd() {}}

　　

public static class DocumentParser extends SaxParser {private Kml kml;private Document document;public DocumentParser(Kml kml) {super(new HashSet<String>());this.kml = kml;childParserQNames.add("ExtendedData");childParserQNames.add("Placemark");}@Overridepublic void parserStart(Attributes attributes) {document = new Document();document.id = attributes.getValue("id");}@Overridepublic void parserElementEnd(String qName, String value) {if(document == null){return;}if(qName.equals("description")){document.description = value;}else if(qName.equals("author")){document.author = value;}}@Overridepublic SaxParser dispatchTo(String qName, Attributes attributes) {if(document == null){return null;}if(qName.equals("ExtendedData")){return new ExtendedData.ExtendedDataParser(document);}else if(qName.equals("Placemark")){return new Placemark.PlacemarkParser(document);}return null;}@Overridepublic void parserEnd() {kml.document = document;}}

　　

public static class PlacemarkParser extends SaxParser {private Document document;private Placemark placemark;public PlacemarkParser(Document document) {super(new HashSet<String>(1));childParserQNames.add("Point");this.document = document;}@Overridepublic void parserStart(Attributes attributes) {placemark = new Placemark();}@Overridepublic void parserElementEnd(String qName, String value) {if(qName.equals("name")){placemark.name = value;}else if(qName.equals("when")){placemark.when = value;}}@Overridepublic SaxParser dispatchTo(String qName, Attributes attributes) {if(qName.equals("Point")){return new Point.PointParser(placemark);}return null;}@Overridepublic void parserEnd() {document.placemark = placemark;}}

　　

public static class ExtendedDataParser extends SaxParser {private Document document;private ExtendedData extendedData;public ExtendedDataParser(Document document) {super(new HashSet<String>(1));childParserQNames.add("Data");this.document = document;}@Overridepublic void parserStart(Attributes attributes) {extendedData = new ExtendedData();}@Overridepublic void parserElementEnd(String qName, String value) {}@Overridepublic SaxParser dispatchTo(String qName, Attributes attributes) {if(qName.equals("Data")){return new Data.DataParser(extendedData);}return null;}@Overridepublic void parserEnd() {document.extendedDatas = extendedData;}}

　　

......

?

解析結果：

?

　　

?

轉載于:https://www.cnblogs.com/John-Chen/p/4644103.html

總結

以上是生活随笔為你收集整理的Android简化xml sax解析的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。