Android使用pull解析xml

一、理论准备

    Pull解析器的运行方式与 SAX 解析器相似。它提供了类似的事件，如：开始元素和结束元素事件，使用parser.next()可以进入下一个元素并触发相应事件。跟SAX不同的是， Pull解析器产生的事件是一个数字，而非方法，因此可以使用一个switch对感兴趣的事件进行处理。当元素开始解析时，调用parser.nextText()方法可以获取下一个Text类型节点的值。

    工程结构如下：

                     

    为什么把xml放在assets目录下呢，它和res/values目录的区别是系统不分配ID，好像没解决问题，暂时没查到资料。

二、上代码

package com.example.and_0003;


import java.io.InputStream;

import java.util.List;


import com.hpu.entity.Student;

import com.hpu.util.PullService;


import android.app.Activity;

import android.content.res.AssetManager;

import android.os.Bundle;

import android.util.Log;


public class MainActivity extends Activity {

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);


        AssetManager asset = getAssets();

        try {

            InputStream input = asset.open("student.xml");

            List<Student> list = PullService.getStudents(input);

            for (Student stu : list) {

                   Log.e("StudentInfo","Person ID: " + stu.getId() + ","

                         + stu.getName() + ", " + stu.getAge() + ", "

                         + stu.getSex());

            }

        } catch (Throwable e) {

            e.printStackTrace();

        }

    }

}

---

  1: <?xml version="1.0" encoding="utf-8"?>

  2: <students>

  3:   <student id="20110806100">

  4:     <name>小明</name>

  5:     <age>22</age>

  6:     <sex>男</sex>

  7:   </student>

  8:   <student id="20110806101">

  9:     <name>小李</name>

 10:     <age>24</age>

 11:     <sex>男</sex>

 12:   </student>

 13:   <student id="20110806102">

 14:     <name>小丽</name>

 15:     <age>21</age>

 16:     <sex>女</sex>

 17:   </student>

 18: </students>

---

package com.hpu.entity;
public class Student {

	private String id;
	private String name;
	private int age;
	private String sex;

	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}

}

---

  1: package com.hpu.util;

  2:

  3: import java.io.InputStream;

  4: import java.util.ArrayList;

  5: import java.util.List;

  6:

  7: import org.xmlpull.v1.XmlPullParser;

  8: import org.xmlpull.v1.XmlPullParserFactory;

  9:

 10: import com.hpu.entity.Student;

 11:

 12: import android.util.Xml;

 13:

 14: public class PullService {

 15:

 16:   // 采用XmlPullParser来解析XML文件

 17:   public static List<Student> getStudents(InputStream inStream)

 18:       throws Throwable {

 19:     List<Student> students = null;

 20:     Student mStudent = null;

 21:

 22:     // ========创建XmlPullParser,有两种方式=======

 23:     // 方式一:使用工厂类XmlPullParserFactory

 24:     XmlPullParserFactory pullFactory = XmlPullParserFactory.newInstance();

 25:     XmlPullParser parser = pullFactory.newPullParser();

 26:     // 方式二:使用Android提供的实用工具类android.util.Xml

 27:     // XmlPullParser parser = Xml.newPullParser();

 28:

 29:     // 解析文件输入流

 30:     parser.setInput(inStream, "UTF-8");

 31:     // 产生第一个事件

 32:     int eventType = parser.getEventType();

 33:     // 只要不是文档结束事件，就一直循环

 34:     while (eventType != XmlPullParser.END_DOCUMENT) {

 35:       switch (eventType) {

 36:       // 触发开始文档事件

 37:       case XmlPullParser.START_DOCUMENT:

 38:         students = new ArrayList<Student>();

 39:         break;

 40:       // 触发开始元素事件

 41:       case XmlPullParser.START_TAG:

 42:         // 获取解析器当前指向的元素的名称

 43:         String name = parser.getName();

 44:         if ("student".equals(name)) {

 45:           // 通过解析器获取id的元素值，并设置student的id

 46:           mStudent = new Student();

 47:           mStudent.setId(parser.getAttributeValue(0));

 48:         }

 49:         if (mStudent != null) {

 50:           if ("name".equals(name)) {

 51:             // 获取解析器当前指向元素的下一个文本节点的值

 52:             mStudent.setName(parser.nextText());

 53:           }

 54:           if ("age".equals(name)) {

 55:             // 获取解析器当前指向元素的下一个文本节点的值

 56:             mStudent.setAge(new Short(parser.nextText()));

 57:           }

 58:           if ("sex".equals(name)) {

 59:             // 获取解析器当前指向元素的下一个文本节点的值

 60:             mStudent.setSex(parser.nextText());

 61:           }

 62:         }

 63:         break;

 64:       // 触发结束元素事件

 65:       case XmlPullParser.END_TAG:

 66:         //

 67:         if ("student".equals(parser.getName())) {

 68:           students.add(mStudent);

 69:           mStudent = null;

 70:         }

 71:         break;

 72:       default:

 73:         break;

 74:       }

 75:       eventType = parser.next();

 76:     }

 77:     return students;

 78:   }

 79:

 80: }

 81: 

四、运行结果

            

五、遗留问题及参考文献

    Dom和SAX和Pull的适用范围分别是什么？

              http://blog.csdn.net/cjjky/article/details/6667744