Android提供了使用SAX,DOM等解析器解析xml文件的功能。 SAX解析器不能用于创建XML文件,而只能用于解析xml文件。
SAX Parser相对于DOM的优势
它比DOM消耗更少的内存。
android SAX Xml解析示例
activity_main.xml
从面板上拖动一个textview。现在,activity_main.xml文件将如下所示:
<RelativeLayout xmlns:androclass="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="75dp"
android:layout_marginTop="46dp"
android:text="TextView" />
</RelativeLayout>
xml文件
在项目的资产目录内创建一个名为file.xml的xml文件。
<?xml version="1.0"?>
<records>
<employee>
<name>Sachin Kumar</name>
<salary>50000</salary>
</employee>
<employee>
<name>Rahul Kumar</name>
<salary>60000</salary>
</employee>
<employee>
<name>John Mike</name>
<salary>70000</salary>
</employee>
</records>
活动类
现在,编写代码以使用sax解析器解析xml。
package com.srcmini.saxxmlparsing;
import java.io.InputStream;
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.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView tv;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv=(TextView)findViewById(R.id.textView1);
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
DefaultHandler handler = new DefaultHandler() {
boolean name = false;
boolean salary = false;
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
if (qName.equalsIgnoreCase("name"))
{
name = true;
}
if (qName.equalsIgnoreCase("salary"))
{
salary = true;
}
}//end of startElement method
public void endElement(String uri, String localName, String qName) throws SAXException {
}
public void characters(char ch[], int start, int length) throws SAXException {
if (name) {
tv.setText(tv.getText()+"\n\n Name : " + new String(ch, start, length));
name = false;
}
if (salary) {
tv.setText(tv.getText()+"\n Salary : " + new String(ch, start, length));
salary = false;
}
}//end of characters
method
};//end of DefaultHandler object
InputStream is = getAssets().open("file.xml");
saxParser.parse(is, handler);
} catch (Exception e) {e.printStackTrace();}
}
}