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