parsing elements with DOM - java

I am stuck I want to parse a tiled map file, and there is one problem. I dont know how can I get x,y,width,height element, and how can I rebuild back this xml. I will be very grateful for your help.
<objectgroup name="Meter">
<object type="meter" x="3232" y="6016" width="512" height="96">
<properties>
<property name="id" value="1"/>
</properties>
</object>
My Java source code:
public void readXml () throws ParserConfigurationException{
File fXmlFile = new File("xml1.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = null;
try {
doc = dBuilder.parse(fXmlFile);
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
doc.getDocumentElement().normalize();
System.out.println(doc.toString());
System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("objectgroup");
System.out.println("----------------------------");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
System.out.println("\nCurrent Element :" + nNode.getNodeName());
System.out.println("\nCurrent Element :" + nNode.getAttributes().getNamedItem("meter"));
}}

You have to make a couple of adjustments, first you have to traverse all the childs and get all the object elements, an then get their attribute values, I know this is not an optimal solution, but will get you what you need:
System.out.println("Root element :"
+ doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("objectgroup");
System.out.println("----------------------------");
for (int temp = 0; temp < nList.getLength(); temp++) {
// for that will go for all objectGroups
Node nNode = nList.item(temp);
NodeList childs = nNode.getChildNodes();
for (int i = 0; i < childs.getLength(); i++) {
Node child = childs.item(i);
if (child.getNodeName().equals("object")) {
// check if we are evaluating an <object> element
System.out.println("\nCurrent Element :"
+ child.getNodeName());
NamedNodeMap attrs = child.getAttributes();
Node x = attrs.item(3), y = attrs.item(4), height = attrs
.item(0), width = attrs.item(2), type = attrs
.item(1);
System.out.println("\n x :" + x.getNodeValue() + " | y : "
+ y.getNodeValue() + " | height: "
+ height.getNodeValue() + " | width: "
+ width.getNodeValue());
}
}
}

Related

Iterating through XML file using JDOM Return NullPointerException?

I want to iterate through XML file using JDOM and I get a NullPointerException in line 67 on my code, I try to store the XML date into a List:
public class ProduitImportXml {
public static List<Produit> getProduits() {
List<Produit> produitsList = new ArrayList<Produit>();
try {
File fXmlFile = new File("ProduitData.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(fXmlFile);
doc.getDocumentElement().normalize(); // optional --------
System.out.println("Root element :"
+ doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("produits");
System.out.println("----------------------------");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
System.out.println("\nCurrent Element :" + nNode.getNodeName());
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element el = (Element) nNode;
int len = nNode.getChildNodes().getLength();
for (int i = 0; i<len; i++)
{
Produit p=new Produit(
el.getElementsByTagName("idProduit").item(0).getTextContent(),//return NullPointerException
el.getElementsByTagName("type").item(0).getTextContent(),
el.getElementsByTagName("marque").item(0).getTextContent(),
el.getElementsByTagName("modele").item(0).getTextContent(),
el.getElementsByTagName("libelle").item(0).getTextContent(),
el.getElementsByTagName("codeTac").item(0).getTextContent(),
el.getElementsByTagName("genCode").item(0).getTextContent());
produitsList.add(p);
}
}
}
}
catch (Exception e) {
e.printStackTrace();
}
return produitsList;
}
}
Any idea about how to solve this problem, this is the console message that I catch:
MessageBodyWriter not found for media type=application/xml, type=class java.util.ArrayList

XML parsing. How can I get child's child?

I'm trying to parse this XML in Java:
<entities>
<entity name="product_section" id="1">
<product_type>3</product_type>
<section_type>1</section_type>
<name>Empresa</name>
<description>d</description>
<position>1</position>
<align>left</align>
<files section_id="1">
<ico id="ico_1" type="normal" src="sections/1/icons/ico.png"></ico>
<ico id="ico_2" type="hover" src="sections/1/icons/ico.png"></ico>
<ico id="ico_3" type="active" src="sections/1/icons/ico.png"></ico>
<img id="img_1" type="normal" src="sections/1/img/pestanya.png"></img>
<img id="img_2" type="hover" src="sections/1/img/pestanya-hover.png"></img>
<img id="img_3" type="active" src="sections/1/img/pestanya-active.png"></img>
<background id="background_1" type="background" position="1" src="sections/1/background/bg1.png"></background>
<background id="background_2" type="background" position="2" src="sections/1/background/bg2.png"></background>
<background id="background_3" type="background" position="3" src="sections/1/background/bg3.png"></background>
</files>
</entity>
But I just achieved to loop through Entities, getting all Entity and each <product_type>, <section_type>, etc.
But I want to loop through files too.
This is my implementation so far:
try {
File contingut = new File("xmlfile.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(contingut);
doc.getDocumentElement().normalize();
System.out.println("root of xml file " + doc.getDocumentElement().getNodeName());
//loop a cada entity
NodeList nodes = doc.getElementsByTagName("entity");
for (int i = 0; i < nodes.getLength(); i++) {
Node node = nodes.item(i);
Element element = (Element) node;
System.out.println("product_type: " + getValue("product_type", element));
System.out.println("section_type: " + getValue("section_type", element));
System.out.println("name: " + getValue("name", element));
System.out.println("description: " + getValue("description", element));
System.out.println("position: " + getValue("position", element));
System.out.println("align: " + getValue("align", element));
}
} catch (Exception e){
e.printStackTrace();
}
getValue function is:
private static String getValue(String tag, Element element) {
NodeList nodes = element.getElementsByTagName(tag).item(0).getChildNodes();
Node node = (Node) nodes.item(0);
return node.getNodeValue();
}
I've done lot of google search, and all I find are "simple" examples, with a parent, and a child, but not child's child.
Any help would be appreciated.
At first one suggestion:
check element type after this Element element = (Element) node;
use this code or something like this :
if (element.getNodeType() == Element.ELEMENT_NODE) { // do smth}
and answer to your question:
You can simply rewrite you code. after you create element you can get all it's child elements by using element.getChildNodes();
it gives you all child tags. After that you write simple for loop where you get each node element from node list like this :
NodeList nodes = element.getChildNodes();
for(int i =0; i < nodes.getLength(); i++){
Element child = (Element) nodes.item(i);
if(child.getNodeType() == Element.ELEMENT_NODE){
String tagName = child.getTagName();
if(!tagName.equals("files")){
System.out.println(tagName + " : " + child.getTextContent());
}else{
NodeList filesChilds = child.getChildNodes();
for(int j = 0; j < filesChilds.getLength(); j++){
//and like above
}
}
}
}

Why is this Java method not returning all XML Elements?

I'm working on reading DMX Values from an XML document. The method only returns one node from the element that I'm trying to pull from but there should be 512.
Here is the method:
public static void readXML(int cueNo){
try {
File fXmlFile = new File(MixWindow.Globals.fileLoc);
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(fXmlFile);
doc.getDocumentElement().normalize();
System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("Cue");
System.out.println("-----------------------");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = (Node) nList.item(temp);
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
System.out.println("Cue Name : " + getTagValue("Cue_Name", eElement));
System.out.println("Cue Number : " + getTagValue("Cue_Number", eElement));
//System.out.println("Nick Name : " + getTagValue("nickname", eElement));
//System.out.println("Salary : " + getTagValue("salary", eElement));
}
}
NodeList nListII = doc.getElementsByTagName("DMX");
//nListII = doc.getElementsByTagName("DMX");
System.out.println("-----------------------");
int length = nListII.getLength();
System.out.println("DMX Length: " + length);
for (int tempII = 0; tempII < nListII.getLength(); tempII++) {
Node nNodeII = (Node) nListII.item(tempII);
if (nNodeII.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNodeII;
System.out.println("DMX Chnl: " + getTagValue("DMX_Chnl", eElement));
System.out.println("DMX Val: " + getTagValue("DMX_Val", eElement));
//System.out.println("Nick Name : " + getTagValue("nickname", eElement));
//System.out.println("Salary : " + getTagValue("salary", eElement));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
private static String getTagValue(String sTag, Element eElement) {
NodeList nlList = eElement.getElementsByTagName(sTag).item(0).getChildNodes();
Node nValue = (Node) nlList.item(0);
return nValue.getNodeValue();
}
}
Here is a portion of the XML file:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<ShowFile>
<Cue>
<Cue_Name>stuff and junk</Cue_Name>
<Cue_Number>1</Cue_Number></Cue>
<DMX>
<DMX_Chnl>1</DMX_Chnl>
<DMX_Val>0</DMX_Val>
<DMX_Chnl>2</DMX_Chnl>
<DMX_Val>0</DMX_Val>
<DMX_Chnl>3</DMX_Chnl>
<DMX_Val>0</DMX_Val>
<DMX_Chnl>4</DMX_Chnl>
<DMX_Val>0</DMX_Val>
......
<DMX_Chnl>512</DMX_Chnl>
<DMX_Val>0</DMX_Val>
System.out created this:
Cue Name : stuff and junk
Cue Number : 1
-----------------------
DMX Length: 1
DMX Chnl: 1
DMX Val : 0
What am I doing wrong?
shortened xml:
<?xml version="1.0" encoding="UTF-8" standalone="no"?><ShowFile><Cue><Cue_Name>Stuff and Junk</Cue_Name><Cue_Number>1</Cue_Number></Cue><DMX><DMX_Chnl>1</DMX_Chnl><DMX_Val>0</DMX_Val><DMX_Cue>1</DMX_Cue><DMX_Chnl>2</DMX_Chnl><DMX_Val>0</DMX_Val><DMX_Cue>1</DMX_Cue><DMX_Chnl>3</DMX_Chnl><DMX_Val>0</DMX_Val><DMX_Cue>1</DMX_Cue><DMX_Chnl>4</DMX_Chnl></DMX></ShowFile>
added loop:
if (nNodeII.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNodeII;
NodeList childNodes = nNodeII.getChildNodes();
String result = new String();
for (int i = 0; i < childNodes.getLength(); i++) {
Node node = childNodes.item(i);
String dcName = node.getNodeName();
String dcVal = node.getNodeValue();
System.out.println("DMX stuff: " + dcName + " " + dcVal);
}
}
Java and the XML parser behave correctly.
But you expect the document to have a different structure than it actually does! So you are looking in the wrong place for nodes, and thus not finding nodes there.
There is only one DMX element. You want to enumerate the children, not the DMX elements.
(i.e. you want to have DMX_Chnl elements, and these are not each wrapped in a separate DMX node)

How to read alternative tags in xml using java?

I have xml file
<A>
<A1>
<A2>Hi</A2>
</A1>
<A>
<B>
<B1></B1>
<B2>100</B2>
</B>
<A>
<A1>
<A2>Hello</A2>
</A1>
<A>
<B>
<B1>1000</B1>
<B2></B2>
</B>
likewise this goes more than 10 blocks. Now my java code able to read one by one that is first reads all after that reads tag.
Code:
public class XMLParse {
static Document doc;
public static void main(String argv[]) {
try {
File file = new File("/home/dev042/Desktop/xxx.xml");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.parse(file);
doc.getDocumentElement().normalize();
System.out.println("Root element " + doc.getDocumentElement().getNodeName());
NodeList nodeLst = doc.getElementsByTagName("A");
System.out.println("Information of all Balence Sheet");
int count = nodeLst.getLength();
String name;
for (int s = 0; s < nodeLst.getLength(); s++) {
Node fstNode = nodeLst.item(s);
if (fstNode.getNodeType() == Node.ELEMENT_NODE) {
Element fstElmnt = (Element) fstNode;
NodeList fstNmElmntLst = fstElmnt.getElementsByTagName("A1");
for(int i =0; i < fstNmElmntLst.getLength(); i++ )
{
Node lst = fstNmElmntLst.item(i);
if(lst.getNodeType() == Node.ELEMENT_NODE)
{
Element fsttravel = (Element) lst;
NodeList secNmElt = fsttravel.getElementsByTagName("*");
name = secNmElt.item(0).getTextContent();
System.out.println("Name : " + name);
}
}
}
}
}
catch (Exception e) {
e.printStackTrace();
}
String amt;
double amount;
NodeList nodeLst = doc.getElementsByTagName("B");
int coun = nodeLst.getLength();
for (int s = 0; s < nodeLst.getLength(); s++) {
Node secNode = nodeLst.item(s);
if (secNode.getNodeType() == Node.ELEMENT_NODE) {
try
{
Element amtval = (Element) secNode;
NodeList secval = amtval.getElementsByTagName("B1");
amt = secval.item(0).getTextContent();
//amount = Double.parseDouble(amt);
System.out.println("SubAmt :" + amt);
NodeList lstNmElmntLst = amtval.getElementsByTagName("B2");
amt = lstNmElmntLst.item(0).getTextContent();
System.out.println("MainAmt : " +amt);
}
catch(Exception ex){
ex.printStackTrace();
}
}
}
}
}
current output:
Hi
Hello
100
1000
I want to read the tags alternatively. then only i can able map the values. How can i read these tags alternatively. output should be like this
Hi 100
Hello 1000
Kindly help me out of it.
Thanks in advance..
I think you need to filter only tags so that your parser will fetch only tags.For this you can use XPath.This is an examples here:
http://www.roseindia.net/tutorials/xPath/java-xpath.shtml

reading from XMl file in java

I have a simple XML file
<requirements>
<requirement>
<name> SwitchON</name>
<id>1</id>
<text>The Light shall turn on when the Switch is on.</text>
</requirement>
<requirement>
<name>SwitchOFF</name>
<id>2</id>
<text>The Light shall turn off when the Switch is off.</text>
</requirement>
<requirement>
<name>Lightbulb</name>
<id>3</id>
<text>The Light bulb shall be connected </text>
</requirement>
<requirement>
<name>Power</name>
<id>4</id>
<text>The Light shall have the power supply</text>
</requirement>
</requirements>
I am trying to show the information in this file in a table model.
I have a method (readFromXMl) that reads the XML file and returns a table model.
public static RequirementTable readFromXMl(String fileName) {
RequirementTable T = new RequirementTable();
Requirement R = new Requirement();
try {
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse(new File(fileName));
doc.getDocumentElement().normalize();
NodeList listOfRequirements = doc.getElementsByTagName("requirement");
int test = listOfRequirements.getLength();
System.out.println("Total no of people : " + test);
for (int i = 0; i < listOfRequirements.getLength(); i++) {
Node RequirementNode = listOfRequirements.item(i);
if (RequirementNode.getNodeType() == Node.ELEMENT_NODE) {
Element RequirementElement = (Element) RequirementNode;
NodeList IdList = RequirementElement.getElementsByTagName("id");
Element IdElement = (Element) IdList.item(0);
NodeList textIdList = IdElement.getChildNodes();
R.setId(Integer.parseInt(textIdList.item(0).getNodeValue()));
NodeList DescriptionList = RequirementElement.getElementsByTagName("text");
Element DescriptionElement = (Element) DescriptionList.item(0);
NodeList textDescriptionList = DescriptionElement.getChildNodes();
R.setText(textDescriptionList.item(0).toString());
NodeList NameList = RequirementElement.getElementsByTagName("name");
Element NameElement = (Element) NameList;
NodeList textNameList = NameElement.getChildNodes();
if (textNameList.item(0).toString().equals("SwitchON")) {
T.addRequirement((SwitchOnReq)R);
} else if (textNameList.item(0).toString().equals("SwitchOFF")) {
T.addRequirement((SwitchOFFReq)R);
} else if (textNameList.item(0).toString().equals("LightBulb")) {
T.addRequirement((BulbRequirement)R);
} else if (textNameList.item(0).toString().equals("Power")) {
T.addRequirement((PowerRequirement)R);
}
}
}
} catch (SAXParseException err) {
System.out.println("** Parsing error" + ", line " + err.getLineNumber() + ", uri " + err.getSystemId());
System.out.println(" " + err.getMessage());
} catch (SAXException e) {
Exception x = e.getException();
((x == null) ? e : x).printStackTrace();
} catch (Throwable t) {
t.printStackTrace();
}
return T;
}
However in this line I am getting an error which says the the pointer is null
Element IdElement = (Element) IdList.item(0); IdElement is null!!
Instead of all the looping and other xml ugliness, let me suggest a little helper method:
private static String getNodeValue(Node n, String path)
throws XPathExpressionException {
XPath xpath = XPathFactory.newInstance().newXPath();
return (String) xpath.evaluate(path, n, XPathConstants.STRING);
}
Use like this:
for (int i = 0; i < listOfRequirements.getLength(); i++) {
Node RequirementNode = listOfRequirements.item(i);
System.out.println("name:" + getNodeValue(RequirementNode, "name"));
System.out.println("id:" + getNodeValue(RequirementNode, "id"));
System.out.println("text:" + getNodeValue(RequirementNode, "text"));
...
to get all the values and set your requirements.

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