Pull 解析/生成 XML文檔

Android內置的XML解析器，運行方式與SAX類似，提供瞭如開始元素和結束元素等事件。
使用parser.next()可進入下一個元素並觸發相應事件，可使用一個switch對感興趣的事件進行選擇和處理。
調用parser.nextText()獲取下一個Text類型元素的值。
可在www.xmlpull.org下載Pull解析器源碼和文檔。
【特點】結構簡單（一個藉口，一個例外，一個工廠組成）；
簡單易用（只用一個重要方法next()檢索下一個事件，
5個事件：START_DOCUMENT,START_TAG,TEXT,END_TAG,END_DOCUMENT）；
多功能性，最小的需求
使用步驟：
①：針對從XML中獲取到的信息，需對其建立一個對象（例：Person）,存放相關信息
②：由Xml.newPullParser()創建XmlPullParser
③：設置資源並指定解析編碼 pullParser.setInput(is, "UTF-8");
④：測試需要，建立一個person.xml文件，內容如下：
<?xml version="1.0" encoding="UTF-8" ?>
<persons>
<person id="23">
<name>Test</name>
<age>21</age>
</person>
</persons> 
⑤：在應用中通過
InputStream is = MainActivity.class.getClassLoader().getResourceAsStream("person.xml");
加載需要解析的文件


*****************************
⑥：生成（保存）xml文檔：
通過Xml.newSerializer()獲取XmlSerializer序列生成器
設置編碼：xSerializer.setOutput(outputStream, "UTF-8");
xSerializer.startDocument("UTF-8", true);
建立File，以OutputStream形式進行生成




【附】：android應用單元測試方法
①：在AndroidManifest.xml中添加節點
<uses-library android:name="android.test.runner" />
<instrumentation android:name="android.test.InstrumentationTestRunner"
        android:targetPackage="cn.gzu.xmlparsertest" />
②：建立測試類繼承AndroidTestCase


【源代碼如下：】
*/
/****************************************【源碼】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文檔 */
	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.單元測試類 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 {

	@Override
	protected 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文檔 */

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.測試生成類方法
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,"張五常",(short)21));
persons.add(new Person(102,"劉麗",(short)20));
persons.add(new Person(103,"吳雪雪",(short)19));
persons.add(new Person(104,"莉莉",(short)23));

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














//9.生成結果 persons.xml
<?xml version='1.0' encoding='UTF-8' standalone='yes' ?>
<persons>
<person id="101">
<name>張五常</name>
<age>21</age>
</person>
<person id="102">
<name>劉麗</name>
<age>20</age>
</person>
<person id="103">
<name>吳雪雪</name>
<age>19</age>
</person>
<person id="104">
<name>莉莉</name>
<age>23</age>
</person>
</persons>
/****************************************【源碼】END**************************************************/