Pull 解析/生成 XML文档

Android内置的XML解析器，运行方式与SAX类似，提供了如开始元素和结束元素等事件。
使用parser.next()可进入下一个元素并触发相应事件，可使用一个switch对感兴趣的事件进行选择和处理。
调用parser.nextText()获取下一个Text类型元素的值。
可在www.xmlpull.org下载Pull解析器源码和文档。
【特点】结构简单（一个借口，一个例外，一个工厂组成）；
简单易用（只用一个重要方法next()检索下一个事件，
5个事件：START_DOCUMENT,START_TAG,TEXT,END_TAG,END_DOCUMENT）；
多功能性，最小的需求
使用步骤：
①：针对从XML中获取到的信息，需对其建立一个对象（例：Person）,存放相关信息
②：由Xml.newPullParser()创建XmlPullParser
③：设置资源并指定解析编码 pullParser.setInput(is, "UTF-8");
④：测试需要，建立一个person.xml文件，内容如下：
<?xml version="1.0" encoding="UTF-8" ?>
<persons>
<person id="23">
<name>Test</name>
<age>21</age>
</person>
</persons> 
⑤：在应用中通过
InputStream is = MainActivity.class.getClassLoader().getResourceAsStream("person.xml");
加载需要解析的文件


*****************************
⑥：生成（保存）xml文档：
通过Xml.newSerializer()获取XmlSerializer序列生成器
设置编码：xSerializer.setOutput(outputStream, "UTF-8");
xSerializer.startDocument("UTF-8", true);
建立File，以OutputStream形式进行生成




【附】：android应用单元测试方法
①：在AndroidManifest.xml中添加节点
<uses-library android:name="android.test.runner" />
<instrumentation android:name="android.test.InstrumentationTestRunner"
        android:targetPackage="cn.gzu.xmlparsertest" />
②：建立测试类继承AndroidTestCase


【源代码如下：】
*/
/****************************************【源码】START**************************************************/

//1.Person.java

public class Person {private Integer id;private String name;private short age;public Person() {super();}public Person(String name, short age) {super();this.name = name;this.age = age;}public Person(Integer id, String name, short age) {super();this.id = id;this.name = name;this.age = age;}// getter and setter ...}

//2.PullParseService.java

public class PullParseService {/** Pull 解析Xml文档 */public static List<Person> getPersons(InputStream is) throws Exception{List<Person> persons = null;Person person = null; XmlPullParser pullParser = Xml.newPullParser(); pullParser.setInput(is, "UTF-8");  int eventType = pullParser.getEventType(); while(eventType!=XmlPullParser.END_DOCUMENT){ switch(eventType){ case XmlPullParser.START_DOCUMENT: persons = new ArrayList<Person>();  break; case XmlPullParser.START_TAG: if("person".equals(pullParser.getName())){ int id = Integer.valueOf(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; }  eventType = pullParser.next(); }return persons;}}

//3.单元测试类 SAXParserTest.java

public class SAXParserTest extends AndroidTestCase {private static final String TAG = "SAXParserTest";public void testPullGetPerson() throws Throwable{InputStream is = this.getClass().getClassLoader().getResourceAsStream("person.xml");List<Person> persons = PullParseService.getPersons(is);String text = "";for(Person p:persons){text = text + "ID: "+p.getId()+" Name: "+p.getName()+" Age: "+p.getAge()+"\n";}Log.i(TAG, text);}}

//4.MainActivity.java

public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);TextView main = (TextView) findViewById(R.id.main_content);InputStream is = MainActivity.class.getClassLoader().getResourceAsStream("person.xml");try {List<Person> persons = testPull(is);String text = "Pull ";for(Person p:persons){text = text + "ID: "+p.getId()+" Name: "+p.getName()+" Age: "+p.getAge()+"\n";}main.setText(text);} catch (Exception e) {e.printStackTrace();}}private List<Person> testPull(InputStream is) throws Exception{return DomParserService.getPersons(is);}}

//6.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="cn.gzu.xmlparsertest"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="18" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <uses-library android:name="android.test.runner" />                <activity            android:name="cn.gzu.xmlparsertest.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application>        <instrumentation android:name="android.test.InstrumentationTestRunner"        android:targetPackage="cn.gzu.xmlparsertest" /></manifest>

//7.xml生成方法（PullParseService.java中）
/** Pull 保存Xml文档 */

public static void save(List<Person> persons,OutputStream os) throws Exception{XmlSerializer xSerializer = Xml.newSerializer();xSerializer.setOutput(os, "UTF-8");xSerializer.startDocument("UTF-8", true);xSerializer.startTag(null, "persons");for(Person person : persons){xSerializer.startTag(null, "person");xSerializer.attribute(null, "id", person.getId().toString());xSerializer.startTag(null, "name");xSerializer.text(person.getName());xSerializer.endTag(null, "name");xSerializer.startTag(null, "age");xSerializer.text(String.valueOf(person.getAge()));xSerializer.endTag(null, "age");xSerializer.endTag(null, "person");}xSerializer.endTag(null, "persons");xSerializer.endDocument();os.flush();os.close();}

//8.测试生成类方法
public void testPullSavePerson() throws Throwable{
File file = new File(this.getContext().getFilesDir(),"persons.xml");
FileOutputStream outputStream = new FileOutputStream(file);
List<Person> persons = new ArrayList<Person>();
persons.add(new Person(101,"张五常",(short)21));
persons.add(new Person(102,"刘丽",(short)20));
persons.add(new Person(103,"吴雪雪",(short)19));
persons.add(new Person(104,"莉莉",(short)23));

PullParseService.save(persons, outputStream);
Log.i(TAG, "***************** testPullSavePerson **************");
}














//9.生成结果 persons.xml
<?xml version='1.0' encoding='UTF-8' standalone='yes' ?>
<persons>
<person id="101">
<name>张五常</name>
<age>21</age>
</person>
<person id="102">
<name>刘丽</name>
<age>20</age>
</person>
<person id="103">
<name>吴雪雪</name>
<age>19</age>
</person>
<person id="104">
<name>莉莉</name>
<age>23</age>
</person>
</persons>
/****************************************【源码】END**************************************************/