android PULL解析XML

Pull解析和Sax解析很相似，都是轻量级的解析，在Adnroid的内核中已经嵌入了XML Pull Parsing提供的org.xmlpull.*

包，所以不需要再添加第三方jar包来支持Pull。PULL解析XML的方式与SAX解析XML方式一样，也是基于事件驱动

的.

得到一个解析器:XmlPullParser parser = Xml.newPullParser();

传进一个输入流:parser.setInput(inStream, "UTF-8");

得到事件类 型:parser.getEventType();

判断是否是文件结尾:XmlPullParser.END_DOCUMENT

判断是否 是文件开始:XmlPullParser.START_DOCUMENT:

判断是否是标签开始:XmlPullParser.START_TAG

判断是否是标签结束:XmlPullParser.END_TAG 

将指针往下推:parser.next();

xmlPullParser中定义了常量来标识各种解析事件：

常量	常量所标识的解析事件
START_DOCUMENT	读取到XML的声明返回
END_DOCUMENT	读取到XML的结束返回
START_TAG	读取到XML的开始标签返回
END_TAG	读取到XML的结束标签返回
TEXT	读取到XML的文本返回

domain：

package com.wangjialin.domain;

public class Person {
private Integer id;
private String name;
private Short age;

public Person() {
}

public Person(Integer id, String name, Short age) {
this.id = id;
this.name = name;
this.age = age;
}

public Person(String name, Short age) {
this.name = name;
this.age = age;
}

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public Short getAge() {
return age;
}

public void setAge(Short age) {
this.age = age;
}

@Override
public String toString() {
return "id=" + id + ",name=" + name + ",age=" + age;
}

}

service：

package com.wangjialin.service;

import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlSerializer;

import android.util.Xml;

import com.wangjialin.domain.Person;

public class PullPersonService {
public static void save(List<Person> persons, OutputStream outStream)
throws Exception {
XmlSerializer serializer = Xml.newSerializer();
serializer.setOutput(outStream, "UTF-8");
serializer.startDocument("UTF-8", true);
serializer.startTag(null, "persons");
for (Person person : persons) {
serializer.startTag(null, "person");
serializer.attribute(null, "id", person.getId().toString());
serializer.startTag(null, "name");
serializer.text(person.getName());
serializer.endTag(null, "name");

serializer.startTag(null, "age");
serializer.text(person.getAge().toString());
serializer.endTag(null, "age");

serializer.endTag(null, "person");
}
serializer.endTag(null, "persons");
serializer.endDocument();
outStream.flush();
outStream.close();
}

public static List<Person> getPersons(InputStream inStream)
throws Exception {
Person person = null;
List<Person> persons = null;
XmlPullParser pullParser = Xml.newPullParser();
pullParser.setInput(inStream, "UTF-8");
int event = pullParser.getEventType();// 触发第一个事件
while (event != XmlPullParser.END_DOCUMENT) {
switch (event) {
case XmlPullParser.START_DOCUMENT:
persons = new ArrayList<Person>();
break;
case XmlPullParser.START_TAG:
if ("person".equals(pullParser.getName())) {
int id = new Integer(pullParser.getAttributeValue(0));
person = new Person();
person.setId(id);
}
if (person != null) {
if ("name".equals(pullParser.getName())) {
person.setName(pullParser.nextText());
}
if ("age".equals(pullParser.getName())) {
person.setAge(new Short(pullParser.nextText()));
}
}
break;

case XmlPullParser.END_TAG:
if ("person".equals(pullParser.getName())) {
persons.add(person);
person = null;
}
break;
}
event = pullParser.next();
}
return persons;
}
}

Activity或test类：

package com.wangjialin.xml;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import android.test.AndroidTestCase;
import android.util.Log;

import com.wangjialin.domain.Person;

import com.wangjialin.service.PullPersonService;

public class PersonServiceTest extends AndroidTestCase {
private static final String TAG = "PersonServiceTest";

public void testPullgetPersons() throws Throwable {
InputStream inStream = this.getClass().getClassLoader()
.getResourceAsStream("wangjialin.xml");
List<Person> persons = PullPersonService.getPersons(inStream);
for (Person person : persons) {
Log.i(TAG, person.toString());
}
}

public void testSave() throws Throwable {
File file = new File(this.getContext().getFilesDir(), "wangjialin.xml");
FileOutputStream outStream = new FileOutputStream(file);
List<Person> persons = new ArrayList<Person>();
persons.add(new Person(90, "wangjialin", (short) 13));
persons.add(new Person(35, "jialingege", (short) 23));
persons.add(new Person(78, "Android", (short) 33));
PullPersonService.save(persons, outStream);
}
}