我想知道如何在BlackBerry上解析XML数据。
我在某处读到JSON是解析xml数据的好方法。
是否有任何教程可以使用JSON或任何其他机制解析XML数据？
答案 0 :(得分：12)
Simple API for XML（SAX）是由公共邮件列表（XML-DEV）的成员开发的。它提供了一种基于事件的XML解析方法。这意味着它不是从节点到节点，而是从事件到事件。 SAX是一个事件驱动的界面。事件包括XML标记，检测错误等， J2ME SAX - 请参阅BlackBerry/J2ME - SAX parse collection of objects with attributes
XML pull parser - 对于需要快速和小型XML解析器的应用程序而言，它是最佳选择。当必须快速有效地执行所有过程以输入元素时，应该使用它 kXML - J2ME pull解析器 - 请参阅Better approach for XML Creation in Blackberry
JSON解析的Blackberry标准是JSON ME
不知道...... JSON可以用XML表示和传输，但反之亦然。
XML（可扩展标记语言）是一组用于以电子方式编码文档的规则。它在W3C生成的XML 1.0规范中定义，以及其他几个相关规范，所有免费开放标准。
XML示例：
<?xml version="1.0" encoding='UTF-8'?>
<painting>
<img src="madonna.jpg" alt='Foligno Madonna, by Raphael'/>
<caption>This is Raphael's "Foligno" Madonna, painted in
<date>1511</date>–<date>1512</date>.
</caption>
</painting>
JSON（JavaScript Object Notation的首字母缩写）是一种基于文本的轻量级开放标准，专为人类可读的数据交换而设计。它源自JavaScript编程语言，用于表示简单的数据结构和关联数组，称为对象（“JSON”中的“O”）。尽管它与JavaScript有关，但它与语言无关，几乎每种编程语言都可以使用解析器。
JSON示例：
{
"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" }
]
}
基本上，如果您的XML与JSON强相当，例如：
<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>
有可能使用JSON解析此类XML。
答案 1 :(得分：3)
解析通常使用可以加载到项目中的第三方库来完成。如果您正在使用XML，我使用了一个名为kXML解析器的库。设置它可能很痛苦，但有关于如何在此设置它的说明 -
http://www.craigagreen.com/index.php?/Blog/blackberry-and-net-webservice-tutorial-part-1.html
使用kXML非常简单。本教程在此解释了如何解析XML文件 -
http://www.roseindia.net/j2me/kxml/j2me-xml-parser.shtml
编辑：哎呀，下一篇文章的第一篇教程对kxml2上的xml解析有一个非常全面的概述。所以我的帖子有点多余。
答案 2 :(得分：2)
/**
* 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
答案 3 :(得分：2)
我做了以下更改以使其正常工作（是的... BB开发网站有时很烦人。）
方法updateField（）中的- 确保添加ui线程，否则不会发生任何更改。
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());
}
}
});
此外，如果您想在本地读取.xml文件（例如在您的文件夹中） - 您显然不需要与端口建立本地主机连接。无论哪种方式，当我使用local：//test.xml运行它时，我一直收到连接错误。去论坛跳了，找到了这个小解决方案。 （是的，我的.xml文件叫做疯人院）。哦，“test.xml.XMLDemoScreen - 是packageName和类名。
Class cl = Class.forName("test.xml.XMLDemoScreen");
InputStream in = cl.getResourceAsStream("/madhouse.xml");
doc = docBuilder.parse(in);
希望有所帮助！ ：d