Android 解析XML 之SAX
Android 解析XML 之SAX
SAX是一种占用内存少且解析速度快的解析器,它采用的是事件启动,它不需要解析完整个文档,而是按照内容顺序 看文档某个部分是否符合xml语法,如果符合就触发相应的事件,所谓的事件就是些回调方法(callback),这些方法 定义在ContentHandler中,下面是其主要方法:
startDocument:当遇到文档的时候就触发这个事件 调用这个方法 可以在其中做些预处理工作
startElement: (String namespaceURI,String localName,String qName,Attributes atts)当遇开始标签的时候就会触发这个方法。
endElement(String uri,String localName,String name):当遇到结束标签时触发这个事件,调用此法可以做些善后工作。
charachers(char [] ch,int start,int length):当遇到xml内容时触发这个方法,用new String(ch,start,length)可以接受内容。
首先在 res目录下新建一个raw文件夹,然后再里面么新建一个student.xml
student.xml
- <?xml version="1.0" encoding="utf-8"?>
- <stundets>
- <student id="2009081315">
- <name>饶伟</name>
- <speciality>计算机科学与技术</speciality>
- <qq>812200157</qq>
- </student>
- <student id="2009081316">
- <name>小伟</name>
- <speciality>网络工程</speciality>
- <qq>812200156</qq>
- </student>
- <student id="2009081318">
- <name>伟哥</name>
- <speciality>软件工程</speciality>
- <qq>812200158</qq>
- </student>
- </stundets>
- public class Student {
- long Id;
- String Name;
- String Speciality;
- long QQ;
- public Student(long id, String name, String speciality, long qQ) {
- super();
- Id = id;
- Name = name;
- Speciality = speciality;
- QQ = qQ;
- }
- public Student() {
- super();
- }
- public long getId() {
- return Id;
- }
- public String getName() {
- return Name;
- }
- public long getQQ() {
- return QQ;
- }
- public String getSpeciality() {
- return Speciality;
- }
- public void setId(long id) {
- Id = id;
- }
- public void setName(String name) {
- Name = name;
- }
- public void setQQ(long qQ) {
- QQ = qQ;
- }
- public void setSpeciality(String speciality) {
- Speciality = speciality;
- }
- }
- package rw.Xml_SAX;
- import java.util.List;
- import org.xml.sax.Attributes;
- import org.xml.sax.SAXException;
- import org.xml.sax.helpers.DefaultHandler;
- import Android.util.Log;
- public class StudentHandler extends DefaultHandler {
- private String preTAG;
- private List<Student> ListStudent;
- private Student stu;
- public StudentHandler() {
- super();
- }
- public StudentHandler(List<Student> listStudent) {
- super();
- ListStudent = listStudent;
- }
- public void startDocument() throws SAXException {
- // TODO Auto-generated method stub
- Log.i("------>", "文档开始");
- super.startDocument();
- }
- public void startElement(String uri, String localName, String qName,
- Attributes attributes) throws SAXException {
- Log.i("localName-------->", localName);
- preTAG=localName;
- if ("student".equals(localName)) {
- stu=new Student();
- stu.setId(Long.parseLong(attributes.getValue(0)));
- for (int i = 0; i < attributes.getLength(); i++) {
- //Log.i("attributes-------->", attributes.getValue(i));
- Log.i("attributes-------->",String.valueOf(stu.getId()));
- }
- }
- super.startElement(uri, localName, qName, attributes);
- }
- public void endDocument() throws SAXException {
- Log.i("------>", "文档结束");
- super.endDocument();
- }
- public void endElement(String uri, String localName, String qName)
- throws SAXException {
- preTAG="";
- if ("student".equals(localName)) {
- ListStudent.add(stu);
- Log.i("-------->", "一个元素解析完成");
- }
- super.endElement(uri, localName, qName);
- }
- public void characters(char[] ch, int start, int length)
- throws SAXException {
- String dateString;
- if ("name".equals(preTAG)) {
- dateString=new String(ch,start,length);
- stu.setName(dateString);
- Log.i("name=", stu.getName());
- }else if ("speciality".equals(preTAG)) {
- dateString=new String(ch,start,length);
- stu.setSpeciality(dateString);
- Log.i("speciality=", stu.getSpeciality());
- }else if ("qq".equals(preTAG)) {
- dateString=new String(ch,start,length);
- stu.setQQ(Long.parseLong((dateString)));
- Log.i("QQ=", String.valueOf(stu.getQQ()));
- }
- super.characters(ch, start, length);
- }
- public List<Student> getListStudent() {
- return ListStudent;
- }
- public void setListStudent(List<Student> listStudent) {
- ListStudent = listStudent;
- }
- }
- import java.util.ArrayList;
- import java.util.Iterator;
- import java.util.List;
- import javax.xml.parsers.SAXParserFactory;
- import org.xml.sax.InputSource;
- import org.xml.sax.XMLReader;
- import android.app.Activity;
- import android.os.Bundle;
- import android.util.Log;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Adapter;
- import android.widget.ArrayAdapter;
- import android.widget.Button;
- import android.widget.ListView;
- import android.widget.TextView;
- public class XMl_Sax1Activity extends Activity {
- private Button button;
- private TextView textView;
- private ListView listView;
- private List<String> list=new ArrayList<String>();
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- button=(Button)findViewById(R.id.button1);
- textView=(TextView)findViewById(R.id.textView1);
- listView=(ListView) findViewById(R.id.listView1);
- //InputSource xMLResourceString=new InputSource(XMl_Sax1Activity.this.getResources().openRawResource(R.raw.student));
- button.setOnClickListener(new ButtonListener());
- }
- class ButtonListener implements OnClickListener{
- @Override
- public void onClick(View v) {
- List<Student> students=parserXMl();
- for (Iterator iterator = students.iterator(); iterator.hasNext();) {
- Student student = (Student) iterator.next();
- list.add(String.valueOf(student.getId())+" "+student.getName()+" "+student.getSpeciality()+" "+String.valueOf((student.getQQ())));
- }
- ArrayAdapter<String> adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, list);
- listView.setAdapter(adapter);
- }
- }
- private List<Student> parserXMl()
- {
- SAXParserFactory factory=SAXParserFactory.newInstance();
- List<Student>students=null;
- Student student=null;
- try {
- XMLReader reader=factory.newSAXParser().getXMLReader();
- students=new ArrayList<Student>();
- reader.setContentHandler(new StudentHandler(students));
- reader.parse(new InputSource(XMl_Sax1Activity.this.getResources().openRawResource(R.raw.student)));
- for (Iterator iterator = students.iterator(); iterator.hasNext();) {
- student = (Student) students.iterator();
- }
- students.add(student);
- } catch (Exception e) {
- // TODO: handle exception
- }
- return students;
- }
- }
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:orientation="vertical"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- >
- <Button android:text="SAX解析" android:id="@+id/button1" android:layout_height="wrap_content" android:layout_width="match_parent"></Button>
- <TextView android:text="" android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
- <ListView android:layout_height="wrap_content" android:id="@+id/listView1" android:layout_width="match_parent"></ListView>
- </LinearLayout>
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