实例教程四：采用Pull解析器解析和生成XML内容

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, MainActivity!</string>
<string name="app_name">XML解析</string>
</resources>

<?xml version="1.0" encoding="UTF-8"?>
<persons>
<person id="23">
<name>LiMing</name>
<age>30</age>
</person>
<person id="20">
<name>ZhangSan</name>
<age>25</age>
</person>
</persons>

package cn.itcast.domain;
public class Person {
private Integer id;
private String name;
private Integer 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 Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", age=" + age + "]";
}
public Person(){
}
public Person(Integer id, String name, Integer age) {
super();
this.id = id;
this.name = name;
this.age = age;
}                
}

package cn.itcast.xml;
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}

package cn.itcast.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.XmlPullParserFactory;
import org.xmlpull.v1.XmlSerializer;
import android.util.Xml;
import cn.itcast.domain.Person;
public class PersonService {
/**
* 获取数据
* @param xml
* @return
* @throws Exception
*/
public static List<Person> getPerson(InputStream xml) throws Exception{
List<Person> persons = null;
Person person = null;
//第一种写法
//                XmlPullParser pullParser = XmlPullParserFactory.newInstance().newPullParser();
//第二种写法
 
XmlPullParser pullParser = Xml.newPullParser();
pullParser.setInput(xml, "UTF-8"); //为Pull解析器设置要解析的XML数据
int event = pullParser.getEventType();
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("name".equals(pullParser.getName())){
String name = pullParser.nextText();
person.setName(name);
}
if("age".equals(pullParser.getName())){
int age = new Integer(pullParser.nextText());
person.setAge(age);
}
break;
case XmlPullParser.END_TAG:
if("person".equals(pullParser.getName())){
persons.add(person);
}
break;
}
event = pullParser.next();
}
return persons;
}
/**
* 保存数据到XML文件中
* @param persons 数据
* @param out 输出方向 
* @throws Exception
*/
public static void save(List<Person> persons, OutputStream out) throws Exception{
XmlSerializer serializer = Xml.newSerializer(); //得到序列化器
 
serializer.setOutput(out, "UTF-8");
serializer.startDocument("UTF-8", true); //true--是否该文件单独存在 
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();
out.flush();
out.close();
}
}

package cn.itcast.test;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import cn.itcast.domain.Person;
import cn.itcast.service.PersonService;
import android.test.AndroidTestCase;
import android.util.Log;
public class PersonServiceTest extends AndroidTestCase{
private static final String TAG = "PersonServiceTest";
public void testPersons() throws Exception{
InputStream xml = this.getClass().getClassLoader().getResourceAsStream("person.xml");
List<Person> persons = PersonService.getPerson(xml);
for(Person person : persons){
Log.i(TAG, person.toString());
}
}
public void testSave() throws Exception{
List<Person> persons = new ArrayList<Person>();
persons.add(new Person(1, "zhangsan", 80));
persons.add(new Person(2, "lisi", 43));
persons.add(new Person(3, "wangwu", 12));
//<包> ///file
 
File xmlFile = new File(getContext().getFilesDir(), "itcast.xml");
FileOutputStream outStream = new FileOutputStream(xmlFile);
PersonService.save(persons, outStream);
}
}