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