Android开发学习---使用XmlPullParser解析xml文件

Android中解析XML的方式主要有三种:sax,dom和pull关于其内容可参考:http://blog.csdn.net/liuhe688/article/details/6415593

本文将主要介绍pull解析器解析xml文件,环境为ubuntu 12.04+ intelij 13.1 + android sdk 2.1

一.创建一个XML项目,步骤如下:

二.解析一个xml文件:

assets/person.xml

<?xml version="1.0" encoding="UTF-8"?>
<persons>
<person id="1101">
<name>amos</name>
<age>30</age>
</person>
<person id="1102">
<name>tom</name>
<age>18</age>
</person>
</persons>

com/amos/xml/domain/Person.java

package com.amos.xml.domain;

/**
* Created by amosli on 14-6-3.
*/

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

public Integer getAge() {
return age;
}

public void setAge(Integer age) {
if (age < 1 || age > 100) {
this.age = 0;
} else {
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;
}
}

com/amos/xml/service/PersonService.java

package com.amos.xml.service;

import android.content.Context;
import android.content.res.AssetManager;
import android.util.Log;
import android.util.Xml;
import com.amos.xml.domain.Person;
import org.xmlpull.v1.XmlPullParser;

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

/**
* Created by amosli on 14-6-3.
*/
public class PersonService {
private Context context;

public PersonService(Context context) {
this.context = context;
}

/**
* 把person.xml的输入流解析转化成list集合
*
* @param
* @return
*/
public List<Person> getPersons(String filename) {

AssetManager manager = context.getAssets();
//初始化项目.
List<Person> persons = null;
Person person = null;

try {
InputStream inputStream = manager.open(filename);
//在android下使用xmlpullparser进行解析
XmlPullParser xmlPullParser = Xml.newPullParser();
//设置xmlpullparser的一些参数
xmlPullParser.setInput(inputStream, "utf-8");

//获取pull解析器对应事件类型
int eventType = xmlPullParser.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
switch (eventType) {
case XmlPullParser.START_DOCUMENT:
persons = new ArrayList<Person>();
break;

case XmlPullParser.START_TAG:
if (xmlPullParser.getName().equals("person")) {
person = new Person();
String id = xmlPullParser.getAttributeValue(0);
Log.d("person.id", id);
person.setId(Integer.parseInt(id));
eventType = xmlPullParser.next();
} else if (xmlPullParser.getName().equals("name")) {
String name = xmlPullParser.nextText();
Log.d("person.name", name);
person.setName(name);
eventType = xmlPullParser.next();
} else if (xmlPullParser.getName().equals("age")) {
String age = xmlPullParser.nextText();
Log.d("person.age", age);
person.setAge(Integer.valueOf(age));
eventType = xmlPullParser.next();
}
break;
case XmlPullParser.END_TAG:
if (xmlPullParser.getName().equals("person")) {
persons.add(person);
person = null;
}
break;
}
eventType = xmlPullParser.next();
}

} catch (Exception e) {
e.printStackTrace();
}
return persons;
}
}

注:这里解析主要用到的是eventType(事件类型),如果是START_DOCUMENT则表示读到文档开始位置,如果是START_TAG,则表示读到文档中的元素开始位置,如<name>,类似的结束位置为END_DOCUMENT和END_TAG;其中要注意判断其事件类型开始的名称是什么,并且取值时,注意其不同位置取值方式也不一样,如<person id="1122">,那么取id的方式为getAttributeValue(int index),另外取<name >amos</name>,则要用nextText()方法进行取值.

/com/amos/xml/MyActivity.java

package com.amos.xml;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
import com.amos.xml.domain.Person;
import com.amos.xml.service.PersonService;

import java.util.List;

public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView show_users = (TextView) findViewById(R.id.show_users);
PersonService personService = new PersonService(this);
StringBuilder stringBuilder = new StringBuilder();
 List<Person> persons = personService.getPersons("person.xml");
for (Person person : persons) {
stringBuilder.append("  " + person.getName()).append(":").append(person.getAge());
}
System.out.println("stringBuilder:" + stringBuilder);
show_users.setText(stringBuilder);
Toast.makeText(this, "数据写入成功!" + stringBuilder, Toast.LENGTH_LONG);
}
}

这里我在主界面定义了一个TextView,用来显示读取到的xml文件的内容,效果如下图所示:

3.测试用例

首先,加入必要的配置:AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.amos.xml"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7"/>
<application android:label="@string/app_name">
  <uses-library android:name="android.test.runner"/>
<activity android:name="MyActivity"
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="com.amos.xml"/>

</manifest>

其中加粗的部分是后加入到项目中的.

其次,写一个testcase:/com/amos/xml/test/TestService.java

package com.amos.xml.test;

import android.test.AndroidTestCase;
import com.amos.xml.domain.Person;
import com.amos.xml.service.PersonService;

import java.util.List;

/**
* Created by amosli on 14-6-3.
*/
public class TestService extends AndroidTestCase {

public void testGetPersons() throws Exception {
 PersonService personService = new PersonService(getContext());
List<Person> persons = personService.getPersons("person.xml");
for (Person person : persons) {
System.out.println(person.getName());
}
}
}

这里想要查看每一步的运行步骤,可以加上断点,intelij 中的快捷键是F8(step over),F7(step into),F9(Resume program).

本文git 地址:https://github.com/amosli/android_basic/tree/xml