Parse XML file on BlackBerry

Question

I want to know how to parse XML data on a BlackBerry.

I read somewhere that JSON is a good method for parsing XML data.

Are there any tutorials for parsing XML data using JSON or any other mechanism?

Answer 1

XML parsing in Blackberry

The Simple API for XML (SAX) was developed by members of the public mailing list (XML-DEV). It provides an event-based approach to XML parsing. This means that instead of moving from node to node, it goes from event to event. SAX is an event driven interface. Events include an XML tag, error detection, etc. J2ME SAX - see BlackBerry / J2ME - SAX parsing a collection of objects with attributes

XML parser - it is optimal for applications that require a fast and small XML parser. It should be used when the whole process needs to be executed quickly and efficiently for inputting kXML elements - J2ME pull parser - see Best approach for creating XML in Blackberry

XML parsing with JSON

Blackberry standard for parsing JSON JSON ME

I don’t know ... JSON can be represented and ported as XML, but not vice versa.

XML (Extensible Markup Language) is a set of rules for encoding documents electronically. It is defined in the XML 1.0 Specification, created by W3C, and several other related specifications, all free open standards.

XML example:

<?xml version="1.0" encoding='UTF-8'?> <painting> <img src="madonna.jpg" alt='Foligno Madonna, by Raphael'/> <caption>This is Raphael "Foligno" Madonna, painted in <date>1511</date>–<date>1512</date>. </caption> </painting> 

JSON (an abbreviation for JavaScript Object Notation) is a lightweight text-based open standard for exchanging data with a person. It is derived from the JavaScript programming language for representing simple data structures and associative arrays called objects ("O" in "JSON"). Despite its connection with JavaScript, it is language independent, and parsers are available for almost any programming language.

JSON example:

 { "firstName": "John", "lastName": "Smith", "age": 25, "address": { "streetAddress": "21 2nd Street", "city": "New York", "state": "NY", "postalCode": "10021" }, "phoneNumber": [ { "type": "home", "number": "212 555-1234" }, { "type": "fax", "number": "646 555-4567" } ] } 

Basically, if your XML is a strong JSON equivalent, for example:

 <Person> <firstName>John</firstName> <lastName>Smith</lastName> <age>25</age> <address> <streetAddress>21 2nd Street</streetAddress> <city>New York</city> <state>NY</state> <postalCode>10021</postalCode> </address> <phoneNumber type="home">212 555-1234</phoneNumber> <phoneNumber type="fax">646 555-4567</phoneNumber> </Person> 

It is possible to parse such XML using JSON.

Answer 2

Analysis is usually performed using a third-party library that can be loaded into the project. If you use XML, I used a library called the kXML parser. Setting it up can be a pain, but there are setup instructions here -

http://supportforums.blackberry.com/t5/Java-Development/Tutorial-How-To-Use-3rd-Party-Libraries-in-your-Applications/mp/177543

http://www.craigagreen.com/index.php?/Blog/blackberry-and-net-webservice-tutorial-part-1.html

Using kXML is pretty straight forward. This guide explains how to parse an XML file -

http://www.roseindia.net/j2me/kxml/j2me-xml-parser.shtml

Edit: Oops, the first tutorial in the next post contains a fairly detailed overview of xml analysis on kxml2. So my post looks redundant.

Answer 3

 /** * class is used to parse the XML response from the server */ package com.rtcf.util; import java.io.IOException; import java.io.InputStream; import java.util.Vector; import javax.microedition.io.Connector; import javax.microedition.io.file.FileConnection; import net.rim.device.api.i18n.DateFormat; import net.rim.device.api.i18n.SimpleDateFormat; import net.rim.device.api.xml.parsers.ParserConfigurationException; import net.rim.device.api.xml.parsers.SAXParser; import net.rim.device.api.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; import com.rtcf.bean.ItemBean; import com.rtcf.bean.SpvItemBean; import com.rtcf.bean.ItemCategoryMappingsBean; import com.rtcf.screen.FirstSyncProgressScreen; import com.rtcf.util.db.SQLManagerSync1; public class ItemXMLParser extends DefaultHandler { //private Statement statement = null; public int currentpage = 1, totalpage = 1; public int maxWidth; private final int BATCH_COUNT = 100; private String tempVal; long startT, endT; private Vector vecItem = new Vector(BATCH_COUNT); private Vector vecItemCategoryMapping = new Vector(BATCH_COUNT); //constructor int roomInsCount = 0; int roomMapInsCount = 0; int TBL_FACILITYCount = 0; int insCount = 0; private FirstSyncProgressScreen fsps; private SQLManagerSync1 tempDb; //constructor public ItemXMLParser(FirstSyncProgressScreen fsps, SQLManagerSync1 tempDb){ this.fsps=fsps; this.tempDb = tempDb; getData(); } /** * Method returns the list of data in a vector (response objects) * @param url * @return Vector */ public void getData(){ FileConnection fconn = null; InputStream inputStream = null; try{ // String url = "http://10.10.1.10/LDS/abcd.xml"; // Logger.debug("HttpConParamUtil.getWebData -------------------- "+url); // HttpConParamUtil.getWebData(url, param, this, method); // HttpConUtilSingle.getWebData(url, this); //Logger.debug("response size -------------- "+response.size()); String fileUrl = "file:///SDCard/Item.xml"; fconn = (FileConnection)Connector.open( fileUrl, Connector.READ); //get a factory SAXParserFactory spf = SAXParserFactory.newInstance(); try { inputStream = fconn.openInputStream(); //get a new instance of parser SAXParser sp = spf.newSAXParser(); //parse the file and also register this class for call backs sp.parse(inputStream, this); }catch(SAXException se) { Logger.error( " startDocument "+se.getMessage(), se); }catch (IOException ie) { Logger.error( " startDocument "+ie, ie); } catch (ParserConfigurationException e) { // TODO Auto-generated catch block Logger.error( " startDocument "+e, e); } catch (Exception e) { // TODO Auto-generated catch block Logger.error( " "+e, e); } } catch (Exception e) { //Logger.debug("### Exception in getData - "+e.getMessage()+" "+e.getClass()); //Dialog.inform("### Exception in getData - "+e.getMessage()+" "+e.getClass()); }finally{ try{ if(inputStream != null){inputStream.close(); } }catch(Exception e){} try{ if(fconn != null){fconn.close(); } }catch(Exception e){} } //return response; }// end getData //=========================================================== // Methods in SAX DocumentHandler //=========================================================== public void startDocument () throws SAXException{ //Logger.debug("################# In startDocument"); DateFormat timeFormat = new SimpleDateFormat("HH.mm.ss"); startT = System.currentTimeMillis(); // String currentTime = timeFormat.format(date); Logger.debug("########## ----------Start time:" + startT); } public void endDocument () throws SAXException{ if( vecItemCategoryMapping.size() > 0){ //fsps.updatedProgress2(22, "Inserting TBL_ITEM_CATEGORY_MAPPING Record "); Logger.debug("Populate TBL_ITEM_CATEGORY_MAPPING..."); tempDb.InsertTbl_item_category_mapping(vecItemCategoryMapping); vecItemCategoryMapping = null; //vecItemCategory = new Vector(BATCH_COUNT); } if( vecItem.size() > 0){ // fsps.updatedProgress2(25, "Inserting TBL_ITEM Record "); Logger.debug("Populate TBL_ITEM..."); tempDb.InsertTbl_item(vecItem); vecItem = null; //vecItem = new Vector(BATCH_COUNT); } } //Event Handlers public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { //Logger.debug("################# In startElement qName : "+qName); if(qName.equals("TBL_ITEM_CATEGORY_MAPPING")){ Logger.debug("Populate TBL_ITEM_CATEGORY_MAPPING..."); populateTblItemCategoryMapping(attributes); } if(qName.equals("TBL_ITEM")){ Logger.debug("Populate TBL_ITEM..."); populateTblItem(attributes); } } public void endElement(String uri, String localName, String qName) throws SAXException { if(qName.equals("TBL_ITEM_CATEGORY_MAPPING")&& vecItemCategoryMapping.size() == BATCH_COUNT){ Logger.debug("Populate TBL_ITEM_CATEGORY..."); tempDb.InsertTbl_item_category_mapping(vecItemCategoryMapping); vecItemCategoryMapping = null; vecItemCategoryMapping = new Vector(BATCH_COUNT); } if(qName.equals("TBL_ITEM")&& vecItem.size() == BATCH_COUNT){ Logger.debug("Populate TBL_ITEM..."); tempDb.InsertTbl_item(vecItem); vecItem = null; vecItem = new Vector(BATCH_COUNT); } } public void characters(char[] ch, int start, int length) throws SAXException { //Logger.debug("################# In characters"); tempVal = new String(ch,start,length); } // reads the xml file and saves the ItemCategoryMappingBean data and adds to vecItemCategoryMapping private void populateTblItemCategoryMapping(Attributes attributes) { try{ ItemCategoryMappingsBean ItemCategoryMappingBean = new ItemCategoryMappingsBean(); try{ if((attributes.getValue("itemCategoryId"))!=null) ItemCategoryMappingBean.itemCategoryId = Integer.parseInt(attributes.getValue("itemCategoryId")); else { ItemCategoryMappingBean.itemCategoryId = -1; } if((attributes.getValue("itemId"))!= null) ItemCategoryMappingBean.itemId = Integer.parseInt(attributes.getValue("itemId")); else { ItemCategoryMappingBean.itemId = -1; } if((attributes.getValue("ddlFlag"))!=null) ItemCategoryMappingBean.ddlFlag = attributes.getValue("ddlFlag").charAt(0); else { ItemCategoryMappingBean.ddlFlag = 'I'; } //ItemCategoryMappingBean.categoryName = (attributes.getValue("categoryName")); Logger.debug("####### populateTblItemCategoryMapping "); }catch(NumberFormatException nfe){ Logger.error("### NumberFormatException SAXXMLParser -->> populateTblItemCategoryMapping() - "+nfe.getMessage(),nfe); } vecItemCategoryMapping.addElement(ItemCategoryMappingBean); }catch(Exception e){ Logger.error("ItemXMLParser -->> populate TblItemCategory() - "+e.getMessage(),e); } } // reads the xml file and saves the ItemBean data and adds to vecItem private void populateTblItem(Attributes attributes) { // TODO Auto-generated method stub ItemBean itemBean= new ItemBean(); try{ try{ itemBean.itemId = Integer.parseInt(attributes.getValue("itemId")); if((attributes.getValue("videoURL"))!=null) itemBean.videoURL = (attributes.getValue("videoURL")); else { itemBean.videoURL = ""; } if((attributes.getValue("itemDescription"))!=null) itemBean.itemDescription = (attributes.getValue("itemDescription")); else { itemBean.itemDescription = ""; } if((attributes.getValue("itemProcedure"))!=null) itemBean.itemProcedure = (attributes.getValue("itemProcedure")); else { itemBean.itemProcedure = ""; } if((attributes. getValue("itemStandard"))!=null) itemBean.itemStandard = (attributes.getValue("itemStandard")); else { itemBean.itemStandard = ""; } if((attributes.getValue("weight"))!=null) itemBean.weight = (attributes.getValue("weight")); else { itemBean.weight = ""; } if((attributes.getValue("ddlFlag"))!=null) itemBean.ddlFlag = attributes.getValue("ddlFlag").charAt(0); else { itemBean.ddlFlag = 'I'; } vecItem.addElement(itemBean); Logger.debug("####### populate TblItem "); }catch(NumberFormatException nfe){ Logger.error("### NumberFormatException SAXXMLParser -->> populateTblItemCategoryMapping() - "+nfe.getMessage(),nfe); } }catch(Exception e){ Logger.error("ItemXMLParser -->> populateTblItemCategory() - "+e.getMessage(),e); } } }// end XMLParser 

Answer 4

This link is from the Blackberry website: http://www.blackberry.com/knowledgecenterpublic/livelink.exe/fetch/2000/348583/800332/800599/How_To_-_Use_the_XML_Parser.html?nodeid=820554&vernum=0

I made the following changes to make it work (Yea ... BB dev site is quite annoying sometimes ..)

in the updateField () method - Be sure to add the ui thread, otherwise no changes will occur.

  UiApplication.getUiApplication().invokeLater(new Runnable() { public void run() { String title="Title"; _screen.add(new RichTextField(node+" : "+element)); if(node.equals(title)) { _screen.add(new SeparatorField()); } } }); 

Also, if you want to read your .xml file locally (for example, in your folder) - you obviously do not need to connect localhost to the port. Anyway, when I ran it with local: //test.xml and I kept getting a connection error. I went to the forum by jumping and found this small solution. (Yes, my .xml file is called madhouse). Oh, and "test.xml.XMLDemoScreen is the package name and class name.

 Class cl = Class.forName("test.xml.XMLDemoScreen"); InputStream in = cl.getResourceAsStream("/madhouse.xml"); doc = docBuilder.parse(in); 

Hope this helps !: D