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Keeping xml elements order in java object as a list of values after conversion of XML file to Java

We have an XML file as mentioned below:-
<Transaction>
<Buyr>
<FrstNm>Vishwa</FrstNm>
</Buyr>
<Buyr>
<FrstNm>PRIYA</FrstNm>
</Buyr>
<Buyr>
<FrstNm>ABCD</FrstNm>
</Buyr>
</Transaction>
Now what is happening after conversion from XML to Java, Java object is populated with element values as List but not in the order they are defined in XML file.
Is there any way to keep the list of values in Java object same as they are defined in XML file?

You are unclear with your requirements. How do you want to store this? How do you want to deal with nested values? Will the tag always be of the same name? Here is a quick piece of code that will grab the value of your leaf node FrstNm
public List<String> populateArrayList(String xml, String tag) throws SAXException, IOException, ParserConfigurationException {
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
InputSource is = new InputSource(new StringReader(xml));
is.getCharacterStream();
Document doc = db.parse(is);
NodeList nodes = doc.getElementsByTagName(tag);
List<String> list = new ArrayList<String>();
for (int i = 0; i < nodes.getLength(); i++) {
list.add(nodes.item(i).getTextContent());
}
return list;
}
Then obviously to call it
populateArrayList("yourXml", "FrstNm")
However I do not like this approach. What is your end goal? There are a lot of better xml technologies out there that might suite your case better. Also that bit of code above only really works for leaf nodes. You need to nest the for loop if you want it to be more thorough. Please post your requirements and we can work off that.

Java: Parse XML child element that may not exist

I'm trying to extract values from an InputStream containing XML data. The general data layout is something like this:
<objects count="1">
<object>
<stuff>...</stuff>
<more_stuff>...</more_stuff>
...
<connections>
<connection>124</connection>
<connection>128</connection>
</connections>
</object>
<objects>
I need to find the integers stored in the <connection> attributes. However, I can't guarantee that there will always be exactly two (there may be just one or none at all). Even more, there will be cases where the element <connections> is not present.
I've been looking at examples like this, but it doesn't mention how to handle cases where a parent is non-existent.
The case where <connections> doesn't exist at all is quite rare (but is something I definitely need to know when it does happen), and the case where it does exist but contains less than two <connection>'s would be even more rare (basically I expect it to never happen).
Should I just assume everything is in place and catch the exception if something happens, or is there a clever way to detect the presence of <connections>?
My initial idea was to use something like:
InputStream response = urlConnection.getInputStream();
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(response);
String xPathExpressionString = "/objects/object/connections/connection";
XPathFactory xPathFactory = XPathFactory.newInstance();
XPath xPath = xPathFactory.newXPath();
XPathExpression expr = xPath.compile(xPathExpressionString);
NodeList nodeList = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++) {
Node intersectionNode = nodeList.item(i);
if (intersectionNode.getNodeType() == Node.ELEMENT_NODE) { // What is this anyway?
// Do something with value
}
}
According to the example linked above, this should handle the case with varying amounts of <connection>'s, but how should I deal with <connections> missing alltoghether.
(Btw, there should always only be a single object, so no need to worry about that)

Use this xpath expression:
"//object//connection"
The "//" construct is a short form for the "self-or-descendants" axis. So the expression above will select all <connection> elements that have an <object> parent.

From the below code we can get all the names of child tags of a document and once we it goes into second if block it means there is connections tag existing as childnode for given doc:
As you said we don't know information about the parent we can use the below line accordingly to the xml present.
group.getChildNodes().item(0).getChildNodes()......
Document doc = dBuilder.parse(inputFile);
doc.getDocumentElement().normalize();
NodeList groupList = doc.getChildNodes().item(0).getChildNodes();
for (int groupCount = 0; groupCount < groupList.getLength(); groupCount++)
{
Node group = groupList.item(groupCount);
if (group.getNodeType() == Node.ELEMENT_NODE)
{
if(group.getNodeName().equals("connections"))
{
}
}
}
My First Answer in Stackoverflow.Hope this helps.

Parse XML file using XPATH expressions and Java

I would like to parse an xml file and i'm using Java and xpath evaluation.
I would like to output the current's node sibling with an xpath expression and without
using getNextSibling() function, is that possible?
e.g. if we read the name element i would like to add the xpath expression ="./address"
in order to output the sibling of "name" without using getNextSibling()/.
The xml file is as follows:
<root>
<name>
<address>
<profession>
</root>
My code is as follows:
package dom_stack4;
import org.w3c.dom.*;
import javax.xml.xpath.*;
import javax.xml.parsers.*;
import java.io.IOException;
import org.xml.sax.SAXException;
public class Dom_stack4 {
public static void main(String[] args) throws ParserConfigurationException, SAXException,
IOException, XPathExpressionException {
// TODO code application logic here
DocumentBuilderFactory domFactory =
DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("root.xml");
XPath xpath = XPathFactory.newInstance().newXPath();
// XPath Query for showing all nodes value
XPathExpression expr = xpath.compile("/root/name/text()");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
System.out.println(" Name is : " + nodes.item(i).getNodeValue());
/* IS that possible here ?? */
/* ./address/text() => outputs the current's node sibling */
expr = xpath.compile("./address/text()");
Object result1 = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes1 = (NodeList) result1;
for (int j = 0; j < nodes1.getLength(); j++) {
System.out.println(" ---------------- " + nodes1.item(j).getNodeValue());
}
}
}
}
Thanks, in advance

First off, it would be good if you were running your code using properly formed xml, the name address and profession tags should be closed or you will get an error when you try to parse it. Secondly, if you want to select the text child of the node, you need to make sure there is actually something there, so your xml should look something like this:
<root>
<name>hi</name>
<address>hi</address>
<profession>hi</profession>
</root>
Now, what you have for selecting the text of the name element is fine, so starting with your IS that possible here ?? comment there are some changes you need to make.
If you want to evaluate a relative XPath, you don't want to be passing your document object to the XPath's evaluate method. The current location that the XPath is being evaluated from is determined by the item that you give to it, and the document object is always evaluated at the root. If you want to evaluate relative to a specific node, rather than giving it the document, give it that node.
So you would have something like this for your evaluate method call:
Object result1 = expr.evaluate(nodes.item(i), XPathConstants.NODESET);
Next, you should make sure that your XPath is actually correct. The node that we currently have selected is the text node of name. Which means we need to first go to the name node instead of the text node. The . expression in XPath syntax selects the current node, so all you are doing with that is selecting the same node. You want the .. expression which selects the parent node.
So with our current XPath of .. we are selecting the name node. What we want to do is select address nodes that are sibilings of the name node. There are two ways we can do this, we could select the parent of the name node, the root node, and select address nodes that are children of that, or we could use an XPath axis to select the siblings (information about axes can be found here http://www.w3schools.com/xpath/xpath_axes.asp)
If we are going through the root node, we would need to select the parent of the parent of our current node so ../.. which gives us the root node, followed by the address children: ../../address/text(), which would give us all address siblings.
Alternatively, using an axis, we could do .. to select the name node followed by ../following-sibling::address (NOTE: this only works if the address nodes are after the name node) and then select the text of the address nodes with ../following-sibling:address/text().
This gives us those two lines as either
expr = xpath.compile("../../address/text()");
Object result1 = expr.evaluate(nodes.item(i), XPathConstants.NODESET);
or
expr = xpath.compile("../following-sibling::address/text()");
Object result1 = expr.evaluate(nodes.item(i), XPathConstants.NODESET);

How to retrieve specific element (or nodelist) within an existing element from DOM in Java

I am trying to parse an XML file which contains multiple records of name A. Each A has multiple group records with name B . The various records within B have names x, y and z.
My questions are:
How do I navigate to B and
how do I obtain all values of x in loop.
The DOM is set to the document (i.e. elements of name "A")
I am using a DOM parser in Java.
Sample record:
<A>
<B><x>123</x><y>asdf</y><z>A345</z></B>
<B><x>987</x><y>ytre</y><z>Z959</z></B>
</A>

Document yourDom = ....;
XPathFactory xpf = XPathFactory.newInstance();
XPath xp = xpf.newXPath();
XPathExpression xpe = xp.compile("//A/B/*");
NodeList nodes = (NodeList) xpe.evaluate(yourDom, XPathConstants.NODESET);

Apart from using the standard DOM API directly which is usually a bit verbose for these tasks, you could also use jOOX as a jquery-like wrapper for DOM. Here's an example how to use it:
// Loop over all x element values within B using css-style selectors
for (String x : $(document).find("B x").texts()) {
// ...
}
// Loop over all x element values within B using XPath
for (String x : $(document).xpath("//B/x").texts()) {
// ...
}
// Loop over all x element values within B using the jOOX API
for (String x : $(document).find("B").children("x").texts()) {
// ...
}

XPath query returns duplicate nodes

I have a SOAP response that I'm processing in Java. It has a element with several different child elements. I'm using the following code to try to grab all of the bond nodes and find which one has a child tag with a value of ACTIVE. The NodeList returned by the initial evaluate statement contains 4 nodes, which is the correct number of children in the SOAP response, but they are all duplicates of the first element. Here is the code:
NodeList nodes = (NodeList)xpath.evaluate("//:bond", doc, XPathConstants.NODESET);
for(int i = 0; i < nodes.getLength(); i++){
HashMap<String, String> map = new HashMap<String, String>();
Element bond = (Element)nodes.item(i);
// Get only active bonds
String status = xpath.evaluate("//:status", bond);
String id = xpath.evaluate("//:instrumentId", bond);
if(!status.equals("ACTIVE"))
continue;
map.put("isin", xpath.evaluate(":isin", bond));
map.put("cusip", xpath.evaluate(":cusip", bond));
}
Thanks for your help,
Jared

The answer to your immediate question is that expressions like //:status will ignore the node that you pass in, and start from the root of the document.
However, there's probably an easier solution than what you've got, by using XPath to apply the test to the node. I think this should work, although it might contain typos (in particular, I can't remember whether text() can stand on its own or must be used in a predicate expression):
//:bond/:status[text()='ACTIVE']/..