Android Development (7) -- parsing XML files by using SAX in Android

1. Write an xml file in the assets File
[Html] v
<? Xml version = "1.0" encoding = "UTF-8"?>
<Persons>
<Person id = "23">
<Name> Li Ming </name>
<Age> 30 </age>
</Person>
<Person id = "20">
<Name> Li xiangmei </name>
<Age> 25 </age>
</Person>
</Persons>

<? Xml version = "1.0" encoding = "UTF-8"?>
<Persons>
<Person id = "23">
<Name> Li Ming </name>
<Age> 30 </age>
</Person>
<Person id = "20">
<Name> Li xiangmei </name>
<Age> 25 </age>
</Person>
</Persons>
2. Write a SAX-parsed class in the service

[Java]
Package com. example. service;

Import java. util. ArrayList;
Import java. util. List;

Import org. xml. sax. Attributes;
Import org. xml. sax. SAXException;
Import org. xml. sax. helpers. DefaultHandler;

Import com. example. domain. Person;

Public class XMLContentHandlerextends DefaultHandler {

// The resolved person object is stored in the list set.
Private List <Person> persons;
// Parse the current person object
Public Person currentPerson;
// Declare the Tag Name
Public String tagName;

// Obtain and parse all person objects
Public List <Person> getPersons (){
Return persons;
}

@ Override
Public void characters (char [] ch, int start, int length)
Throws SAXException {

Super. characters (ch, start, length );
// First, judge whether the tagName is empty.
If (tagName! = Null ){
String data = new String (ch, start, length );
// Determine whether the tag is empty
If (tagName. equals ("name ")){
CurrentPerson. setName (data );
} Else if (tagName. equals ("age") {// determine whether the tag is age
CurrentPerson. setAge (short) Integer. parseInt (data ));
}
}
}

@ Override
Public void endDocument () throws SAXException {

Super. endDocument ();
}

@ Override
Public void endElement (String uri, String localName, String qName)
Throws SAXException {

Super. endElement (uri, localName, qName );
// Store the person object to the collection when the person Tag ends
If (localName. equals ("person ")){
Persons. add (currentPerson );
CurrentPerson = null;
}

This. tagName = null;
}

/**
* Events triggered at the beginning of the document
*/
@ Override
Public void startDocument () throws SAXException {

Super. startDocument ();
Persons = new ArrayList <Person> ();
}

@ Override
Public void startElement (String uri, String localName, String qName,
Attributes attributes) throws SAXException {

Super. startElement (uri, localName, qName, attributes );
// Determine whether the parsed tag is person
If (localName. equals ("person ")){
CurrentPerson = new Person ();
// Parse the value of the id attribute and assign the id value to the currentPerson object
CurrentPerson. setId (Integer. parseInt (attributes. getValue (0 )));
}

This. tagName = localName;
}

}
[Java]
Package com. example. service;
 
Import java. util. ArrayList;
Import java. util. List;
 
Import org. xml. sax. Attributes;
Import org. xml. sax. SAXException;
Import org. xml. sax. helpers. DefaultHandler;
 
Import com. example. domain. Person;
 
Public class XMLContentHandler extends DefaultHandler {
 
// The resolved person object is stored in the list set.
Private List <Person> persons;
// Parse the current person object
Public Person currentPerson;
// Declare the Tag Name
Public String tagName;


// Obtain and parse all person objects
Public List <Person> getPersons (){
Return persons;
}

@ Override
Public void characters (char [] ch, int start, int length)
Throws SAXException {

Super. characters (ch, start, length );
// First, judge whether the tagName is empty.
If (tagName! = Null ){
String data = new String (ch, start, length );
// Determine whether the tag is empty
If (tagName. equals ("name ")){
CurrentPerson. setName (data );
} Else if (tagName. equals ("age") {// determine whether the tag is age
CurrentPerson. setAge (short) Integer. parseInt (data ));
}
}
}
 
@ Override
Public void endDocument () throws SAXException {

Super. endDocument ();
}
 
@ Override
Public void endElement (String uri, String localName, String qName)
Throws SAXException {

Super. endElement (uri, localName, qName );
// Store the person object to the collection when the person Tag ends
If (localName. equals ("person ")){
Persons. add (currentPerson );
CurrentPerson = null;
}

This. tagName = null;
}
 
/**
* Events triggered at the beginning of the document
*/
@ Override
Public void startDocument () throws SAXException {

Super. startDocument ();
Persons = new ArrayList <Person> ();
}
 
@ Override
Public void startElement (String uri, String localName, String qName,
Attributes attributes) throws SAXException {

Super. startElement (uri, localName, qName, attributes );
// Determine whether the parsed tag is person
If (localName. equals ("person ")){
CurrentPerson = new Person ();
// Parse the value of the id attribute and assign the id value to the currentPerson object
CurrentPerson. setId (Integer. parseInt (attributes. getValue (0 )));
}

This. tagName = localName;
}

}

Package com. example. service;

Import java. util. ArrayList;
Import java. util. List;

Import org. xml. sax. Attributes;
Import org. xml. sax. SAXException;
Import org. xml. sax. helpers. DefaultHandler;

Import com. example. domain. Person;

Public class XMLContentHandler extends DefaultHandler {

// The resolved person object is stored in the list set.
Private List <Person> persons;
// Parse the current person object
Public Person currentPerson;
// Declare the Tag Name
Public String tagName;


// Obtain and parse all person objects
Public List <Person> getPersons (){
Return persons;
}
 
@ Override
Public void characters (char [] ch, int start, int length)
Throws SAXException {

Super. characters (ch, start, length );
// First, judge whether the tagName is empty.
If (tagName! = Null ){
String data = new String (ch, start, length );
// Determine whether the tag is empty
If (tagName. equals ("name ")){
CurrentPerson. setName (data );
} Else if (tagName. equals ("age") {// determine whether the tag is age
CurrentPerson. setAge (short) Integer. parseInt (data ));
}
}
}

@ Override
Public void endDocument () throws SAXException {

Super. endDocument ();
}

@ Override
Public void endElement (String uri, String localName, String qName)
Throws SAXException {

Super. endElement (uri, localName, qName );
// Store the person object to the collection when the person Tag ends
If (localName. equals ("person ")){
Persons. add (currentPerson );
CurrentPerson = null;
}

This. tagName = null;
}

/**
* Events triggered at the beginning of the document
*/
@ Override
Public void startDocument () throws SAXException {

Super. startDocument ();
Persons = new ArrayList <Person> ();
}

@ Override
Public void startElement (String uri, String localName, String qName,
Attributes attributes) throws SAXException {

Super. startElement (uri, localName, qName, attributes );
// Determine whether the parsed tag is person
If (localName. equals ("person ")){
CurrentPerson = new Person ();
// Parse the value of the id attribute and assign the id value to the currentPerson object
CurrentPerson. setId (Integer. parseInt (attributes. getValue (0 )));
}

This. tagName = localName;
}
 
}
3. Get the operations of the SAX class in the Activity
[Java]
Package com. example. lession03_xml;

Import java. io. InputStream;
Import java. util. List;

Import javax. xml. parsers. SAXParser;
Import javax. xml. parsers. SAXParserFactory;

Import com. example. domain. Person;
Import com. example. service. XMLContentHandler;
Import com. example. service. XMLDomService;

 

Import android. OS. Bundle;
Import android. app. Activity;
Import android. view. Menu;
Import android. view. View;
Import android. view. View. OnClickListener;
Import android. view. inputmethod. InputBinding;
Import android. widget. Button;
Import android. widget. Toast;

Public class XmlActivityextends Activity {

// Declare the component
Public Button btn_sax, btn_dom, btn_pull;

Public XMLDomService xmlDomService;

@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
// Set the displayed view
SetContentView (R. layout. activity_xml );

XmlDomService = new XMLDomService ();
// Obtain the component by id
Btn_sax = (Button) findViewById (R. id. btn_sax );
Btn_dom = (Button) findViewById (R. id. btn_dom );
Btn_pull = (Button) findViewById (R. id. btn_pull );

// Register an event for the button
Btn_sax.setOnClickListener (new MyOnclickListener ());
Btn_dom.setOnClickListener (new MyOnclickListener ());
Btn_pull.setOnClickListener (new MyOnclickListener ());
}

@ Override
Public boolean onCreateOptionsMenu (Menu menu ){
// Inflate the menu; this adds items to the action bar if it is present.
GetMenuInflater (). inflate (R. menu. xml, menu );
Return true;
}

// Anonymous class
Class MyOnclickListener implements OnClickListener {

@ Override
Public void onClick (View v ){
Int id = v. getId ();
Switch (id ){
Case R. id. btn_sax:
Toast. makeText (XmlActivity. this, "using SAX Parsing", Toast. LENGTH_LONG). show ();
Try {
// The factory object parsed by SAX
SAXParserFactory factory = SAXParserFactory. newInstance ();
// Get the sax Parser
SAXParser saxParser = factory. newSAXParser ();
// Create a handler object
XMLContentHandler handlerService = new XMLContentHandler ();
InputStream is = getAssets (). open ("csdn. xml ");
// Directly parse
SaxParser. parse (is, handlerService );
// Get it through the handlerService object
Toast. makeText (XmlActivity. this, "----" + handlerService, Toast. LENGTH_LONG). show ();
} Catch (Exception e ){
E. printStackTrace ();
}

Break;
Case R. id. btn_dom:

InputStream is = null;
Try {
// Obtain the input stream object for reading the file
Is = getAssets (). open ("csdn. xml ");
// Use dom for parsing
List <Person> persons = xmlDomService. parseXML (is );
// Simple test
// Toast. makeText (XmlActivity. this, "" + persons. get (0). getName (), Toast. LENGTH_LONG). show ();
Toast. makeText (XmlActivity. this, "using DOM Parsing" + persons. get (0). getName (), Toast. LENGTH_LONG). show ();
} Catch (Exception e ){
E. printStackTrace ();
}

Break;
Case R. id. btn_pull:
Toast. makeText (XmlActivity. this, "Use PULL Parsing", Toast. LENGTH_LONG). show ();
Break;

Default:
Break;
}

}

}
}

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