本篇文章主要介绍了 Android 创建与解析 XML(二)——详解 Dom4j 方式, 这里整理了详细的代码, 有需要的小伙伴可以参考下。
Android 是一种基于 Linux 的自由及开放源代码的操作系统,主要使用于移动设备,如智能手机和平板电脑,由 Google 公司和开放手机联盟领导及开发。尚未有统一中文名称,中国大陆地区较多人使用 "安卓" 或 "安致"。
1、Dom4j 概述
dom4j is an easy to use, open source library for working with XML, XPath and XSLT on the Java platform using the Java Collections Framework and with full support for DOM, SAX and JAXP.
dom4j 官方网址:{aa2aa}
dom4j 源码下载:{aa1aa}
本示例中,需要导入 dom4j.jar 包,才能引用 dom4j 相关类,dom4j 源码和 jar 包,请见本示例【源码下载】或访问 dom4j
org.dom4j 包,不仅包含创建 xml 的构建器类 DocumentHelper、Element,而且还包含解析 xml 的解析器 SAXReader、Element,包含类如下:
org.dom4j
创建和解析 xml 的效果图:
2、Dom4j 创建 XML
Dom4j,创建 xml 主要用到了 org.dom4j.DocumentHelper、org.dom4j.Document、org.dom4j.io.OutputFormat、org.dom4j.io.XMLWriter
首先,DocumentHelper.createDocument(),创建 org.dom4j.Document 的实例 doc
接着,通过 doc,设置 xml 属性 doc.setXMLEncoding("utf-8")、doc.addElement("root") 根节点,以及子节点等
然后,定义 xml 格式并输出,new XMLWriter(xmlWriter, outputFormat)
- /** Dom4j方式,创建 XML */
- public String dom4jXMLCreate(){
- StringWriter xmlWriter = new StringWriter();
- Person []persons = new Person[3]; // 创建节点Person对象
- persons[0] = new Person(1, "sunboy_2050", "http://blogcsdnnet/sunboy_2050");
- persons[1] = new Person(2, "baidu", "http://wwwbaiducom");
- persons[2] = new Person(3, "google", "http://wwwgooglecom");
- try {
- orgdom4jDocument doc = DocumentHelpercreateDocument();
- docsetXMLEncoding("utf-8");
- orgdom4jElement eleRoot = docaddElement("root");
- eleRootaddAttribute("author", "homer");
- eleRootaddAttribute("date", "2012-04-25");
- eleRootaddComment("dom4j test");
- int personsLen = personslength;
- for(int i=0; i<personsLen; i++){
- Element elePerson = eleRootaddElement("person"); // 创建person节点,引用类为 orgdom4jElement
- Element eleId = elePersonaddElement("id");
- eleIdaddText(persons[i]getId()+"");
- Element eleName = elePersonaddElement("name");
- eleNameaddText(persons[i]getName());
- Element eleBlog = elePersonaddElement("blog");
- eleBlogaddText(persons[i]getBlog());
- }
- orgdom4jioOutputFormat outputFormat = new orgdom4jioOutputFormat(); // 设置xml输出格式
- outputFormatsetEncoding("utf-8");
- outputFormatsetIndent(false);
- outputFormatsetNewlines(true);
- outputFormatsetTrimText(true);
- orgdom4jioXMLWriter output = new XMLWriter(xmlWriter, outputFormat); // 保存xml
- outputwrite(doc);
- outputclose();
- } catch (Exception e) {
- eprintStackTrace();
- }
- savedXML(fileName, xmlWritertoString());
- return xmlWritertoString();
- }
运行结果:
3、Dom4j 解析 XML
Dom4j,解析 xml 主要用到了 org.dom4j.io.SAXReader、org.dom4j.Document、doc.getRootElement(),以及 ele.getName()、ele.getText() 等
首先,创建 SAXReader 的实例 reader,读入 xml 字节流 reader.read(is)
接着,通过 doc.getRootElement() 得到 root 根节点,利用迭代器取得 root 下一级的子节点 eleRoot.elementIterator() 等
然后,得到解析的 xml 内容 xmlWriter.append(xmlHeader)、xmlWriter.append(personsList.get(i).toString())
解析一:标准解析(Iterator 迭代)
- /** Dom4j方式,解析 XML */
- public String dom4jXMLResolve(){
- StringWriter xmlWriter = new StringWriter();
- InputStream is = readXML(fileName);
- try {
- SAXReader reader = new SAXReader();
- orgdom4jDocument doc = readerread(is);
- List<Person> personsList = null;
- Person person = null;
- StringBuffer xmlHeader = new StringBuffer();
- Element eleRoot = docgetRootElement(); // 获得root根节点,引用类为 orgdom4jElement
- String attrAuthor = eleRootattributeValue("author");
- String attrDate = eleRootattributeValue("date");
- xmlHeaderappend("root")append("\t\t");
- xmlHeaderappend(attrAuthor)append("\t");
- xmlHeaderappend(attrDate)append("\n");
- personsList = new ArrayList<Person>();
- // 获取root子节点,即person
- Iterator<Element> iter = eleRootelementIterator();
- for(; iterhasNext(); ) {
- Element elePerson = (Element)iternext();
- if("person"equals(elePersongetName())){
- person = new Person();
- // 获取person子节点,即id、name、blog
- Iterator<Element> innerIter = elePersonelementIterator();
- for(; innerIterhasNext();) {
- Element ele = (Element)innerIternext();
- if("id"equals(elegetName())) {
- String id = elegetText();
- personsetId(IntegerparseInt(id));
- } else if("name"equals(elegetName())) {
- String name = elegetText();
- personsetName(name);
- } else if("blog"equals(elegetName())) {
- String blog = elegetText();
- personsetBlog(blog);
- }
- }
- personsListadd(person);
- person = null;
- }
- }
- xmlWriterappend(xmlHeader);
- int personsLen = personsListsize();
- for(int i=0; i<personsLen; i++) {
- xmlWriterappend(personsListget(i)toString());
- }
- } catch (DocumentException e) {
- eprintStackTrace();
- } catch (Exception e) {
- eprintStackTrace();
- }
- return xmlWritertoString();
- }
运行结果:
解析二:选择性解析(XPath 路径)
Dom4j+XPath,选择性只解析 id,doc.selectNodes("//root//person//id")
- /** Dom4j方式,解析 XML(方式二) */
- public String dom4jXMLResolve2(){
- StringWriter xmlWriter = new StringWriter();
- InputStream is = readXML(fileName);
- try {
- orgdom4jioSAXReader reader = new orgdom4jioSAXReader();
- orgdom4jDocument doc = readerread(is);
- List<Person> personsList = null;
- Person person = null;
- StringBuffer xmlHeader = new StringBuffer();
- Element eleRoot = docgetRootElement(); // 获得root根节点,引用类为 orgdom4jElement
- String attrAuthor = eleRootattributeValue("author");
- String attrDate = eleRootattributeValue("date");
- xmlHeaderappend("root")append("\t\t");
- xmlHeaderappend(attrAuthor)append("\t");
- xmlHeaderappend(attrDate)append("\n");
- personsList = new ArrayList<Person>();
- @SuppressWarnings("unchecked")
- List<Element> idList = (List<Element>) docselectNodes("//root//person//id"); // 选择性获取全部id
- Iterator<Element> idIter = idListiterator();
- while(idIterhasNext()){
- person = new Person();
- Element idEle = (Element)idIternext();
- String id = idElegetText();
- personsetId(IntegerparseInt(id));
- personsListadd(person);
- }
- xmlWriterappend(xmlHeader);
- int personsLen = personsListsize();
- for(int i=0; i<personsLen; i++) {
- xmlWriterappend("id = ")append(personsListget(i)getId()+"")append("\n");
- }
- } catch (DocumentException e) {
- eprintStackTrace();
- } catch (Exception e) {
- eprintStackTrace();
- }
- return xmlWritertoString();
- }
注:借助 XPath 解析 XML 时,需要导入 jaxen;
Jaxen is an open source XPath library written in Java. It is adaptable to many different object models, including DOM, XOM, dom4j, and JDOM. Is it also possible to write adapters that treat non-XML trees such as compiled Java byte code or Java beans as XML, thus enabling you to query these trees with XPath too.
运行结果:
4、Person 类
请参见前面博客 {aa0aa} 【4、Person 类】
来源: http://www.phperz.com/article/17/0315/310650.html