SAX是一个解析速度快并且占用内存少的xml解析器，非常适合用于Android等移动设备。 SAX解析XML文件采用的是事件驱动，也就是说，它并不需要解析完整个文档，在按内容顺序解析文档的过程中，SAX会判断当前读到的字符是否合法XML语法中的某部分，如果符合就会触发事件。所谓事件，其实就是一些回调（callback）方法，这些方法(事件)定义在ContentHandler接口。下面是一些ContentHandler接口常用的方法：
startDocument()：当遇到文档的开头的时候，调用这个方法，可以在其中做一些预处理的工作。
endDocument()：和上面的方法相对应，当文档结束的时候，调用这个方法，可以在其中做一些善后的工作。
startElement(String namespaceURI, String localName, String qName, Attributes atts) ：当读到一个开始标签的时候，会触发这个方法。namespaceURI就是命名空间，localName是不带命名空间前缀的标签名，qName是带命名空间前缀的标签名。通过atts可以得到所有的属性名和相应的值。要注意的是SAX中一个重要的特点就是它的流式处理，当遇到一个标签的时候，它并不会纪录下以前所碰到的标签，也就是说，在startElement()方法中，所有你所知道的信息，就是标签的名字和属性，至于标签的嵌套结构，上层标签的名字，是否有子元属等等其它与结构相关的信息，都是不得而知的，都需要你的程序来完成。这使得SAX在编程处理上没有DOM来得那么方便。
endElement(String uri, String localName, String name)：这个方法和上面的方法相对应，在遇到结束标签的时候，调用这个方法。
characters(char[] ch, int start, int length) ：这个方法用来处理在XML文件中读到的内容，第一个参数为文件的字符串内容，后面两个参数是读到的字符串在这个数组中的起始位置和长度，使用new String(ch,start,length)就可以获取内容。
示例代码：
MainActivity.java
package cn.lixyz.xmltest.activity;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import cn.lixyz.xmltest.R;
import cn.lixyz.xmltest.model.Student;
import cn.lixyz.xmltest.parser.DOMForXML;
import cn.lixyz.xmltest.parser.PULLForXML;
import cn.lixyz.xmltest.parser.SAXForXML;
public class MainActivity extends Activity {
private Button bt_readxml_dom, bt_writexml_dom, bt_writexml_sax, bt_readxml_sax, bt_readxml_pull, bt_writexml_pull;
private List<Student> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findView();
}
private void findView() {
bt_readxml_dom = (Button) findViewById(R.id.bt_readxml_dom);
bt_writexml_dom = (Button) findViewById(R.id.bt_writexml_dom);
bt_writexml_sax = (Button) findViewById(R.id.bt_writexml_sax);
bt_readxml_sax = (Button) findViewById(R.id.bt_readxml_sax);
bt_readxml_pull = (Button) findViewById(R.id.bt_readxml_pull);
bt_writexml_pull = (Button) findViewById(R.id.bt_writexml_pull);
}
public void clickButton(View view) {
DOMForXML domForXML;
SAXForXML saxForXML;
PULLForXML pullForXML;
switch (view.getId()) {
case R.id.bt_readxml_dom:
domForXML = new DOMForXML();
domForXML.domReadXML();
break;
case R.id.bt_writexml_dom:
domForXML = new DOMForXML();
domForXML.domWriterXML();
break;
case R.id.bt_readxml_sax:
saxForXML = new SAXForXML();
saxForXML.saxReaderXML();
break;
case R.id.bt_writexml_sax:
saxForXML = new SAXForXML();
saxForXML.saxWriterXML();
break;
case R.id.bt_writexml_pull:
pullForXML = new PULLForXML();
pullForXML.pullWriterXML();
break;
case R.id.bt_readxml_pull:
pullForXML = new PULLForXML();
pullForXML.pullReaderXML();
break;
}
}
}
activity_main.xml
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="cn.lixyz.xmltest.activity.MainActivity" >
<Button
android:id="@+id/bt_writexml_dom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="DOM方式生成XML" />
<Button
android:id="@+id/bt_readxml_dom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="DOM方式读取XML" />
<Button
android:id="@+id/bt_writexml_sax"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="SAX方式生成XML" />
<Button
android:id="@+id/bt_readxml_sax"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="SAX方式读取XML" />
<Button
android:id="@+id/bt_writexml_pull"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="PULL生成XML" />
<Button
android:id="@+id/bt_readxml_pull"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="clickButton"
android:text="PULL解析XML" />
</LinearLayout>
</ScrollView>
SAXForXML.java
package cn.lixyz.xmltest.parser;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import android.util.Log;
import cn.lixyz.xmltest.model.Student;
public class SAXForXML {
public void saxWriterXML() {
try {
// 数据源
List<Student> listData = createStudents();
SAXTransformerFactory saxTransformerFactory = (SAXTransformerFactory) SAXTransformerFactory.newInstance();
TransformerHandler transformerHandler = saxTransformerFactory.newTransformerHandler();
// 设置xml属性
Transformer transformer = transformerHandler.getTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes"); // 是否缩进
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8"); // 字符集
transformer.setOutputProperty(OutputKeys.VERSION, "1.0"); // 版本号
File fileFolder = new File("data/data/cn.lixyz.xmltest/files");
if (!fileFolder.exists()) {
fileFolder.mkdir();
Log.d("TTTT", "文件夹不存在，已经创建");
}
FileOutputStream fileOutputStream = new FileOutputStream(
new File("data/data/cn.lixyz.xmltest/files/studentsForSAX.xml"));
transformerHandler.setResult(new StreamResult(fileOutputStream));
transformerHandler.startDocument();
AttributesImpl attributesImpl = new AttributesImpl();
attributesImpl.clear();
transformerHandler.startElement("", "", "students", attributesImpl);
for (Student student : listData) {
attributesImpl.clear();
attributesImpl.addAttribute("", "", "id", "", student.getId() + "");
transformerHandler.startElement("", "", "student", attributesImpl);
attributesImpl.clear();
transformerHandler.startElement("", "", "name", attributesImpl);
transformerHandler.characters(student.getName().toCharArray(), 0, student.getName().length());
;
transformerHandler.endElement("", "", "name");
attributesImpl.clear();
transformerHandler.startElement("", "", "age", attributesImpl);
transformerHandler.characters((student.getAge() + "").toCharArray(), 0, student.getName().length());
;
transformerHandler.endElement("", "", "age");
transformerHandler.endElement("", "", "student");
}
transformerHandler.endElement("", "", "students");
transformerHandler.endDocument();
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void saxReaderXML() {
try {
SAXStudentService studentService = new SAXStudentService();
// InputStream inputStream =
// this.getClass().getClassLoader().getResourceAsStream("person.xml");
FileInputStream fileInputStream = new FileInputStream(
new File("data/data/cn.lixyz.xmltest/files/studentsForSAX.xml"));
List<Student> students = studentService.getStudents(fileInputStream);
for (Student student : students) {
Log.d("TTTT", "id=" + student.getId() + ",name=" + student.getName() + ",age=" + student.getAge());
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Throwable e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// 模拟生成xml的数据
private List<Student> createStudents() {
List<Student> listData = new ArrayList<Student>();
listData = new ArrayList<Student>();
Student s1 = new Student();
s1.setId(11);
s1.setName("张三");
s1.setAge(10);
listData.add(s1);
Student s2 = new Student();
s2.setId(22);
s2.setName("李四");
s2.setAge(11);
listData.add(s2);
Student s3 = new Student();
s3.setId(33);
s3.setName("王五");
s3.setAge(12);
listData.add(s3);
Student s4 = new Student();
s4.setId(44);
s4.setName("赵六");
s4.setAge(13);
listData.add(s4);
Student s5 = new Student();
s5.setId(55);
s5.setName("刘七");
s5.setAge(14);
listData.add(s5);
return listData;
}
}
Student.java
package cn.lixyz.xmltest.model;
public class Student {
private int id;
private String name;
private int age;
public int getId() {
return id;
}
public void setId(int 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;
}
}
SAXStudentService.java
package cn.lixyz.xmltest.parser;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import android.util.Log;
import cn.lixyz.xmltest.model.Student;
public class SAXStudentService {
public List<Student> getStudents(InputStream inputStream) throws Throwable {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
StudentHandler studentHandel = new StudentHandler();
parser.parse(inputStream, studentHandel);
return studentHandel.getStudent();
}
class StudentHandler extends DefaultHandler {
private List<Student> dataList;
private String tag;
private Student student;
public List<Student> getStudent() {
return dataList;
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
// TODO Auto-generated method stub
// super.characters(ch, start, length);
if (tag != null) {
Log.d("TTTT", "~~~~~~~");
String str = new String(ch, start, length);
if ("name".equals(tag)) {
student.setName(str);
} else if ("age".equals(tag)) {
student.setAge(Integer.parseInt(str));
}
}
}
@Override
public void startElement(String uri, String localName, String qName, Attributes attributes)
throws SAXException {
// TODO Auto-generated method stub
// super.startElement(uri, localName, qName, attributes);
if ("student".equals(localName)) {
student = new Student();
Integer id = new Integer(attributes.getValue(0));
student.setId(id);
}
tag = localName;
}
@Override
public void startDocument() throws SAXException {
// TODO Auto-generated method stub
// super.startDocument();
dataList = new ArrayList<Student>();
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
// TODO Auto-generated method stub
// super.endElement(uri, localName, qName);
if ("student".equals(localName)) {
dataList.add(student);
student = null;
}
tag = null;
}
}
}
来源：https://www.cnblogs.com/xs104/p/4924755.html