Analysis on the event type of the Android XML file parser Pull Parsing Method

In the process of parsing XML files, it is found that the API documentation does not provide detailed description of parsing events, which brings a lot of troubles to parsing XML files, today we have a demo of Event Type Analysis to share with you.

Step 1: Create an Android project file without any changes. You only need to write an xmlTest () method in the onCreate () method. The Code is as follows:

[Java]
Package com. example. xmltest;
 
Import java. io. IOException;
 
Import org. xmlpull. v1.XmlPullParser;
Import org. xmlpull. v1.XmlPullParserException;
 
Import android. app. Activity;
Import android. content. res. XmlResourceParser;
Import android. OS. Bundle;
 
Public class MainActivity extends Activity {
 
@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. activity_main );
XmlTest ();
}
 
/**
* Test the event type in the Pull parsing method.
*/
Private void xmlTest (){
// Define the Event Type
Int eventType = 0;
Try {
XmlResourceParser xrp = getResources (). getXml (R. xml. timezones );
// When an xml file is obtained, XmlResourceParser points to the beginning of the document.
EventType = xrp. getEventType ();
// System. out. println ("-------->" + eventType); // view the event Value
While (eventType! = XmlPullParser. END_DOCUMENT ){
Switch (eventType ){
Case XmlPullParser. START_DOCUMENT:
System. out. println ("Start document ");
Break;
Case XmlPullParser. START_TAG:
System. out. println ("Start tag" + xrp. getName ());
Break;
Case XmlPullParser. TEXT:
System. out. println ("Text" + xrp. getText ());
Break;
Case XmlPullParser. END_TAG:
System. out. println ("End tag" + xrp. getName ());
Break;
Default:
Break;
}
EventType = xrp. next ();
// System. out. println ("-------->" + eventType); // view the event Value
}
} Catch (XmlPullParserException e ){
E. printStackTrace ();
} Catch (IOException e ){
E. printStackTrace ();
}
// Determine whether the event type is end of the document
If (eventType = XmlPullParser. END_DOCUMENT ){
System. out. println ("End document ");
}
}
}

Package com. example. xmltest;

Import java. io. IOException;

Import org. xmlpull. v1.XmlPullParser;
Import org. xmlpull. v1.XmlPullParserException;

Import android. app. Activity;
Import android. content. res. XmlResourceParser;
Import android. OS. Bundle;

Public class MainActivity extends Activity {

@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. activity_main );
XmlTest ();
}

/**
* Test the event type in the Pull parsing method.
*/
Private void xmlTest (){
// Define the Event Type
Int eventType = 0;
Try {
XmlResourceParser xrp = getResources (). getXml (R. xml. timezones );
// When an xml file is obtained, XmlResourceParser points to the beginning of the document.
EventType = xrp. getEventType ();
// System. out. println ("-------->" + eventType); // view the event Value
While (eventType! = XmlPullParser. END_DOCUMENT ){
Switch (eventType ){
Case XmlPullParser. START_DOCUMENT:
System. out. println ("Start document ");
Break;
Case XmlPullParser. START_TAG:
System. out. println ("Start tag" + xrp. getName ());
Break;
Case XmlPullParser. TEXT:
System. out. println ("Text" + xrp. getText ());
Break;
Case XmlPullParser. END_TAG:
System. out. println ("End tag" + xrp. getName ());
Break;
Default:
Break;
}
EventType = xrp. next ();
// System. out. println ("-------->" + eventType); // view the event Value
}
} Catch (XmlPullParserException e ){
E. printStackTrace ();
} Catch (IOException e ){
E. printStackTrace ();
}
// Determine whether the event type is end of the document
If (eventType = XmlPullParser. END_DOCUMENT ){
System. out. println ("End document ");
}
}
}
Step 2: the above Code uses a timezones. the following code copies the following code to the Android project file --> res --> xml Folder: [html] view plaincopyprint? <? Xml version = "1.0" encoding = "UTF-8"?>
<Timezones>
<Timezone id = "Pacific/Majuro"> majunaro </timezone>
<Timezone id = "Pacific/Midway"> Midway Island </timezone>
</Timezones>

<? Xml version = "1.0" encoding = "UTF-8"?>
<Timezones>
<Timezone id = "Pacific/Majuro"> majunaro </timezone>
<Timezone id = "Pacific/Midway"> Midway Island </timezone>
</Timezones> Part 3: run the program on the simulator. The following information is displayed on LogCat:

The output is analyzed as follows:

1. we can see that the Start document is printed twice, indicating that when the program instantiates the XmlResourceParser object, the default event of the Pull parser is XmlPullParser. START_DOCUMENT, when one XmlResourceParser is executed. after next (), the event still points to XmlPullParser. START_DOCUMENT.

2. Then execute XmlResourceParser. next () to get an event in sequence.

3. Common events include XmlPullParser. START_DOCUMENT, XmlPullParser. START_TAG, XmlPullParser. TEXTXmlPullParser. END_TAG, and XmlPullParser. END_DOCUMENT.