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Android開發8——利用pull解析器讀寫XML文件
一、基本介紹
對XML解析有SAX和DOM等多種方式，Android中極力推薦xmlpull方式解析xml。xmlpull不僅可用在Android上同樣也適用於javase，但在javase環境中需自己獲取xmlpull所依賴的類庫，kxml2-2.3.0.jar，xmlpull_1_1_3_4c.jar。
jar包下載網址
https://www.xmlpull.org/
https://kxml.sourceforge.net/
二、例子
讀取到xml的聲明返回數字0 START_DOCUMENT;
讀取到xml的結束返回數字1 END_DOCUMENT ;
讀取到xml的開始標簽返回數字2 START_TAG
讀取到xml的結束標簽返回數字3 END_TAG
讀取到xml的文本返回數字4 TEXT
<?xml version="1.0" encoding="UTF-8"?> <people> <person > <name>XY1</name> <age>22</age> </person> <person > <name>XY2</name> <age>22</age> </person> </people>
package cn.xy.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 cn.xy.model.Person;
/**
* 利用pull解析器解析XML
*
* @author XY
*
*/
public class PersonService
{
/**
* 從XML文件中讀取數據
*
* @param xml XML文件輸入流
*/
public List<Person> getPeople(InputStream xml) throws Exception
{
List<Person> lst = null;
Person person = null;
// 利用ANDROID提供的API快速獲得pull解析器
XmlPullParser pullParser = Xml.newPullParser();
// 設置需要解析的XML數據
pullParser.setInput(xml, "UTF-8");
// 取得事件
int event = pullParser.getEventType();
// 若為解析到末尾
while (event != XmlPullParser.END_DOCUMENT) // 文檔結束
{
String nodeName = pullParser.getName();
switch (event)
{
case XmlPullParser.START_DOCUMENT: // 文檔開始
lst = new ArrayList<Person>();
break;
case XmlPullParser.START_TAG: // 標簽開始
if ("person".equals(nodeName))
{
String id = pullParser.getAttributeValue(0);
person = new Person();
person.setId(id);
}
if ("name".equals(nodeName))
{
String name = pullParser.nextText();
person.setName(name);
}
if ("age".equals(nodeName))
{
int age = Integer.valueOf(pullParser.nextText());
person.setAge(age);
}
break;
case XmlPullParser.END_TAG: // 標簽結束
if ("person".equals(nodeName))
{
lst.add(person);
person = null;
}
break;
}
event = pullParser.next(); // 下一個標簽
}
return lst;
}
/**
* 向XML寫入數據
*
* @param os
* @param person
* @throws Exception
*/
public void saveDataToXML(OutputStream os, List<Person> lst) throws Exception
{
XmlSerializer xs = Xml.newSerializer();
xs.setOutput(os, "UTF-8");
xs.startDocument("UTF-8", true);
xs.startTag(null, "people");
for (Person p : lst)
{
xs.startTag(null, "person");
xs.attribute(null, "person", p.getId());
xs.startTag(null, "name");
xs.text(p.getName());
xs.endTag(null, "name");
xs.startTag(null, "age");
xs.text(p.getAge().toString());
xs.endTag(null, "age");
xs.endTag(null, "person");
}
xs.endTag(null, "people");
xs.endDocument();
os.flush();
os.close();
}
}
public class TestClass extends AndroidTestCase
{
public void testPeople() throws Exception
{
PersonService ps = new PersonService();
InputStream xml = this.getClass().getClassLoader().getResourceAsStream("person.xml");
List<Person> lst = ps.getPeople(xml);
Assert.assertEquals("XY1", lst.get(0).getName());
}
public void testSave() throws Exception
{
PersonService ps = new PersonService();
List<Person> lst = new ArrayList<Person>();
lst.add(new Person("0001", "XY0001", 20));
lst.add(new Person("0002", "XY0002", 20));
File xmlFile = new File(this.getContext().getFilesDir(), "xy.xml"); // data/data/package name/files
OutputStream os = new FileOutputStream(xmlFile);
ps.saveDataToXML(os, lst);
}
}
最後更新：2017-04-03 05:40:39