本来一直忙着期末考试的复习，但复习挺无聊的，偶然看到xml的解析方法，虽然以前做过，但感觉不是很熟悉了，所以抽点时间一口气把三种方式都复习了遍。这三种方法中DOM最耗内存，因为它是把整个文件加载进去然后进行分类整理的，PULL和SAX类似，只是SAX要用到一个解析类，类中的主要三个方法完成内容的解析，而PULL方法是Android特有的，根据获得的标签判断并解析，这也是安卓中最常使用的方法。
接下来给大家复习下，因为我觉得看代码更容易明白，讲解的就不多了。
首先我们准备好我们要解析的资源文件和封装好的javaBean。
person.xml
<?xml version="1.0" encoding="UTF-8"?>
<persons>
<person id="1">
<name>sax</name>
<age>12</age>
</person>
<person id="2">
<name>ganganrou</name>
<age>17</age>
</person>
<person id="3">
<name>nuanwozi</name>
<age>5</age>
</person>
</persons>
封装好的javaBean
public class PersonBean {
int id;
String name;
String age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
@Override
public String toString() {
return "PersonBean [id=" + id + ",name=" + name + ",age=" + age + "]";
}
}
接下来我们分别以DOM、SAX、PULL的方式对person.xml文件进行解析并封装到javaBean中去：
一、DOM
public static List<PersonBean> getPersonBeans() {
List<PersonBean> list = new ArrayList<PersonBean>();
DocumentBuilderFactory builderFactory = DocumentBuilderFactory
.newInstance();
try {
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document document = builder.parse(DomPaserHelper.class
.getClassLoader().getResourceAsStream("person2.xml"));
Element element = document.getDocumentElement();
NodeList nodeList = element.getElementsByTagName("person");
for (int i = 0; i < nodeList.getLength(); i++) {
Element node = (Element) nodeList.item(i);
PersonBean bean = new PersonBean();
bean.setId(Integer.valueOf(node.getAttribute("id")));
NodeList list2 = node.getChildNodes();
for (int j = 0; j < list2.getLength(); j++) {
Node element2 = list2.item(j);
<span style="color:#ff6600;">// 判断子Note的类型为元素Note</span>
if (element2.getNodeType() == Node.ELEMENT_NODE) {
Element childElement = (Element) element2;
if ("name".equals(childElement.getNodeName())) {
bean.setName(childElement.<span style="color:#ff6600;">getFirstChild</span>()
.getNodeValue());
}
if ("age".equals(childElement.getNodeName())) {
bean.setAge(childElement.<span style="color:#ff6600;">getFirstChild</span>()
.getNodeValue());
}
}
}
list.add(bean);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
二、PULL
public static List<PersonBean> getPersonBeans() {
List<PersonBean> list = null;
boolean f = false;
PersonBean bean = null;
XmlPullParserFactory pullParserFactory;
try {
pullParserFactory = XmlPullParserFactory.newInstance();
XmlPullParser parser = pullParserFactory.newPullParser();
parser.setInput(PullPaserHelper.class.getClassLoader()
.getResourceAsStream("person3.xml"),"utf-8");
int tag = parser.getEventType();
while (tag != XmlPullParser.END_DOCUMENT) {
switch (tag) {
case XmlPullParser.START_DOCUMENT:
list = new ArrayList<PersonBean>();
break;
case XmlPullParser.START_TAG:
String str = parser.getName();
if (str.equals("person")) {
bean = new PersonBean();
bean.setId(Integer.valueOf(parser.getAttributeValue(0)));
f = true;
}
if (f&&bean!=null) {
if ("name".equals(str)) {
bean.setName(parser.nextText());
}
if ("age".equals(str)) {
bean.setAge(parser.nextText());
}
}
break;
case XmlPullParser.END_TAG:
String con = parser.getName();
if (con.equals("person") && bean != null) {
list.add(bean);
bean = null;
f = false;
}
break;
default:
break;
}
tag = parser.next();
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
三、SAX
public class SaxHanderHelper extends DefaultHandler {
List<PersonBean> personBeans;
String tag;
public List<PersonBean> getPersonBeans() {
return personBeans;
}
public SaxHanderHelper() {
// TODO Auto-generated constructor stub
personBeans = new ArrayList<PersonBean>();
}
PersonBean bean;
@Override
public void startElement(String uri,String localName,String qName,//在这里获取标签和标签的属性
Attributes attributes) throws SAXException {
// TODO Auto-generated method stub
if (localName.equals("person")) {
bean = new PersonBean();
for (int i = 0; i < attributes.getLength(); i++) {
bean.setId(Integer.valueOf(attributes.getValue(i)));
}
}
tag = localName;
}
@Override
public void endElement(String uri,String qName)
throws SAXException {
// TODO Auto-generated method stub
if (localName.equals("person") && bean != null) {
personBeans.add(bean);
bean = null;
}
tag = null;
}
@Override
public void characters(char[] ch,int start,int length)//在这里获取标签的值
throws SAXException {
// TODO Auto-generated method stub
String content = new String(ch,start,length).trim();
if (tag != null) {
if (tag.equals("age")) {
bean.setAge(content);
}
if (tag.equals("name")) {
bean.setName(content);
}
}
}
}
SAXParser saxParser = factory.newSAXParser(); SaxHanderHelper handerHelper = new SaxHanderHelper(); saxParser.parse(getInputStream(),handerHelper); List<PersonBean> beans = handerHelper.getPersonBeans();
