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XML - Extract One tag Value

I have to extract tag value from an xml Document that contains a single tag like below:
<error>Permission denied</error>
i have tried:
String xmlRecords = "<error>Permission denied</error>"
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xmlRecords));
Document doc = db.parse(is);
Node nodes = doc.getFirstChild();
String = nodes.getNodeValue();
but it dont works.
How can i do it ?

Use doc.getDocumentElement().getTextContent() to get the string Permission denied.

With DOM it´s util to know the structure of the XML document, and which node level are you looking for.
After get Document, you can use document.getElementsByTagName("root") to look for the root or father tags, and get the childs as a list to look for the item. Something like this:
NodeList listresults = document.getElementsByTagName('father/root element string');
NodeList nl = listresults.item(0).getChildNodes();
// Recorremos los nodos
for (int temp = 0; temp < nl.getLength(); temp++) {
Node node = nl.item(temp);
// Check if it is a node
if (node.getNodeType() == Node.ELEMENT_NODE) {
Element element = (Element) node;
if(element.getNodeName().equals("error")){
// check the element
}
}
}
I hope this helps you.

just try following code.
String value = nodes.getTextContent();

You have to construct the string if you are using the above approach. You will get the string values of the tag name and content using the functions.
Tag name = nodes.getTextContent()
tag value = nodes.getLocalName()

I guess this is what you want
Element element = document.getDocumentElement();
NodeList errorTagList = element.getElementsByTagName("error");
if (errorTagList != null && errorTagList.getLength() > 0) {
NodeList errorTagSubList = errorTagList.item(0).getChildNodes();
if (errorTagSubList != null && errorTagSubList.getLength() > 0) {
String value = errorTagSubList.item(0).getNodeValue();
}
}

dom parser getElement

I want to only get restaurants in beirut with dom parser please help
this is a part from my xml file :
city -> beirut->restaurants->restaurant->name->
tyr->restaurants->restaurant->name->
jbeil->restaurants->restaurant->name->
<restaurants>
<restaurant>
<name>
...
</restaurant>
</restaurants>
<restaurants>
<restaurant>
<name>
...
</restaurant>
</restaurants>
<restaurants>
<restaurant>
<name>
...
</restaurant>
</restaurants>
because this code give me all restaurants in all city's :
try {
File inputFile = new File("src/josephXml.xml");
DocumentBuilderFactory dbFactory
= DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(inputFile);
doc.getDocumentElement().normalize();
NodeList nList = doc.getElementsByTagName("Restaurant");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
jTextArea1.append( "\n"+"Name : "+ eElement
.getElementsByTagName("name")
.item(0)
.getTextContent()+"\n "
, i only want restaurants in beirut please help

You use Restaurant, but your file uses restaurant. It's not OK, because case sensitive.
use XPath: you can select many things, it is very readable.
Replace this in your code:
XPath xPath = XPathFactory.newInstance().newXPath();
String expression="/city/beirut/restaurants/restaurant";
NodeList nList = (NodeList) xPath.compile(expression).evaluate(document, XPathConstants.NODESET);

update xml document using xpath

Hello this is my xml document :
<city>
<beirut>
<restaurant>
<name>sada</name>
</restaurant>
</beirut>
<jbeil>
<restaurant>
<name>toto</name>
<rating>4.3/5</rating>
</restaurant>
<restaurant>
<name>jojo</name>
<rating>4.3/5</rating>
</restaurant>
</jbeil>
<sour>
<restaurant>
<name>sada</name>
</restaurant>
</sour>
</city>
I want to update the rating of "jojo" restaurant in jbeil from 4.3/5 to 4.5/5 using xpath and netbeans please help ,
this code give the rating ,
try {
File inputFile = new File("src/xpath/josephXml.xml");
DocumentBuilderFactory dbFactory
= DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder;
dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(inputFile);
doc.getDocumentElement().normalize();
XPath xPath = XPathFactory.newInstance().newXPath();
String expression = "/City/Jbeil/Restaurant";
NodeList nodeList = (NodeList) xPath.compile(expression).evaluate(doc, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++) {
Node nNode = nodeList.item(i);
System.out.println("\nCurrent Element :"
+ nNode.getNodeName());
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
System.out.println("rating : "
+ eElement
.getElementsByTagName("rating")
.item(0)
.getTextContent());
and i want only to update the rating of restaurant in jbeil where name is "jojo" , please help

This is one possible XPath to find such restaurant named jojo in the city of jbeil and then return the corresponding rating element :
/city/jbeil/restaurant[name='jojo']/rating
Notice that XML & XPath are case-sensitive, so I used all lower-case characters in the above XPath to match the XML posted in this question.
I don't know much about Java, but quick searching over the internet* suggest something like this :
XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "/city/jbeil/restaurant[name='jojo']/rating";
Element e = (Element)xpath.evaluate(expression, doc, XPathConstant.NODE);
if (e != null)
e.setTextContent("4.5/5");
*) how to modify xml tag specific value in java?

navigating hierarchy of xml input file

How do I list the element names at a given level in an xml schema hierarchy? The code I have below is listing all element names at every level of the hierarchy, with no concept of nesting.
Here is my xml file:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?><?xml-stylesheet type="text/xsl" href="CDA.xsl"?>
<SomeDocument xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:something">
<title>some title</title>
<languageCode code="en-US"/>
<versionNumber value="1"/>
<recordTarget>
<someRole>
<id extension="998991"/>
<addr use="HP">
<streetAddressLine>1357 Amber Drive</streetAddressLine>
<city>Beaverton</city>
<state>OR</state>
<postalCode>97867</postalCode>
<country>US</country>
</addr>
<telecom value="tel:(816)276-6909" use="HP"/>
</someRole>
</recordTarget>
</SomeDocument>
Here is my java method for importing and iterating the xml file:
public static void parseFile() {
//get the factory
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
//Using factory get an instance of document builder
DocumentBuilder db = dbf.newDocumentBuilder();
//parse using builder to get DOM representation of the XML file
Document dom = db.parse("D:\\mypath\\somefile.xml");
//get the root element
Element docEle = dom.getDocumentElement();
//get a nodelist of elements
NodeList nl = docEle.getElementsByTagName("*");
if (nl != null && nl.getLength() > 0) {
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
System.out.println("node.getNodeName() is: "+node.getNodeName());
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
The output of the above program is:
title
languageCode
versionNumber
recordTarget
someRole
id
addr
streetAddressLine
city
state
postalCode
country
telecom
Instead, I would like to output the following:
title
languageCode
versionNumber
recordTarget
It would be nice to then be able to list the children of recordTarget as someRole, and then to list the children of someRole as id, addr, and telecom. And so on, but at my discretion in the code. How can I change my code to get the output that I want?

You're getting all nodes with this line:
NodeList nl = docEle.getElementsByTagName("*");
Change it to
NodeList nl = docEle.getChildNodes();
to get all of its children. Your print statement will then give you the output you're looking for.
Then, when you iterate through your NodeList, you can choose to call the same method on each Node you create:
NodeList children = node.getChildNodes();
If you want to print an XML-like structure, perhaps a recursive method that prints all child nodes is what you are looking for.

You could re-write the parseFile (I'd rather call it parseChildrenElementNames) method to take an input String that specifies the element name for which you want to print out its children element names:
public static void parseChildrenElementNames(String parentElementName) {
// get the factory
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
// Using factory get an instance of document builder
DocumentBuilder db = dbf.newDocumentBuilder();
// parse using builder to get DOM representation of the XML file
Document dom = db
.parse("D:\\mypath\\somefile.xml");
// get the root element
NodeList elementsByTagName = dom.getElementsByTagName(parentElementName);
if(elementsByTagName != null) {
Node parentElement = elementsByTagName.item(0);
// get a nodelist of elements
NodeList nl = parentElement.getChildNodes();
if (nl != null) {
for (int i = 0; i < nl.getLength(); i++) {
Node node = nl.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
System.out.println("node.getNodeName() is: "
+ node.getNodeName());
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
However, this will only consider the first element that matches the specified name.
For example, to get the list of elements under the first node named someRole, you would call parseChildrenElementNames("someRole"); which would print out:
node.getNodeName() is: id
node.getNodeName() is: addr
node.getNodeName() is: telecom

how to get attribute of given node?

I am trying to write DOM XML parsing.
My Xml file
<?xml version="1.0"?>
<BLAH>
<AgentNm type="citi1">
<accName>accName1</accName>
<accType>accType1</accType>
<someThing>someThing1</someThing>
<amt>100000</amt>
</AgentNm>
<AgentNm type="citi2">
<accName>accName2</accName>
<accType>accType2</accType>
<someThing>someThing2</someThing>
<amt>200000</amt>
</AgentNm>
</BLAH>
And i tried following java code
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse (new File("c:\\file.xml"));
// normalize text representation
doc.getDocumentElement ().normalize ();
System.out.println ("Root element of the doc is " +doc.getDocumentElement().getNodeName());
NodeList agentNm = doc.getElementsByTagName("AgentNm");
int totalAgentNm = agentNm.getLength();
System.out.println("Total no of Agents : " + totalAgentNm);
for(int s=0; s<agentNm.getLength() ; s++){
Node firstPersonNode = agentNm.item(s);
if(firstPersonNode.getNodeType() == Node.ELEMENT_NODE){
Element firstPersonElement = (Element)firstPersonNode;
PrintNodeElem(firstPersonElement,"type");
}//end of if clause
}//end of for loop with s var
static void PrintNodeElem(Element nodeElem,String elem){
NodeList someThingList = nodeElem.getElementsByTagName(elem);
Element ageElement = (Element)someThingList.item(0);
NodeList textAgeList = ageElement.getChildNodes();
System.out.println(elem+" : " +((Node)textAgeList.item(0)).getNodeValue().trim());
}
But, when i tried to execute above method,
i am getting null pointer exception.
can any one explain me, how to fix this.

if you want an attribute of a given node, I would suggest XPath. It is much easier.
http://onjava.com/onjava/2005/01/12/xpath.html