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Retrieving child node data from node data

I want to use DOM4j to parse an XML file in Java.

I have this XML as an example:

<request method="POST" url="/devices/test/planner" body="*"> <response statusCode="200"> <header> <headerParameters> <headerParameter name="Content-Type"> Content-Type=application/xml </headerParameter> </headerParameters> </header> <body>booking created!</body> </response> </request>

Given a query (first node) node, how can I retrieve data from child nodes?

For example, getting the status code <response> or attributes of the name <headerParameter> ?

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2 answers

Assuming you get a “request” node as an Element , you can do something like this:

 Element response = (Element) request.elements().get(0); int statusCode = Integer.parseInt(response.attribute("statusCode"));

If you want to move the guys recursively, you will have to write iterative (or recursive) code to visit each item in the list returned by elements() .

[Edit] You can also use XPath to extract the specific elements you are looking for:

 int statusCode = Integer.parseInt( request.selectSingleNode("response/@statusCode").getText()); String firstHeaderName = request.selectSingleNode( "response/headerParameters/headerParameter/@name").getText();
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Retrieving child node data from a given node using dom4j:

1. Place this Java code in the Main.java file:

 import java.util.*; import java.io.*; import org.dom4j.*; import org.dom4j.io.*; class Foo{ String moo; String baz; } class Main{ public static Document parse(String filePath) throws DocumentException { SAXReader reader = new SAXReader(); Document document = reader.read(filePath); return document; } public static void main(String[] args){ try{ File f = new File("/tmp/myxml.xml"); Document document = parse(f.toString()); List list = document.selectNodes("//penguins/PieHole"); Foo foo = new Foo(); Iterator iter=list.iterator(); while(iter.hasNext()){ Element element=(Element)iter.next(); foo.moo = element.selectSingleNode("cupcake").getText(); foo.baz = element.selectSingleNode("montana").getText(); } System.out.println("foo.moo: " + foo.moo); System.out.println("foo.baz: " + foo.baz); } catch(Exception e){ e.printStackTrace(); } System.out.println("done"); } }

2. Put this in a file called /tmp/myxml.xml:

 <?xml version="1.0" encoding="utf-8"?> <penguins> <mars>129</mars> <PieHole> <cupcake>value inside cupcake</cupcake> <montana>value inside montana</montana> </PieHole> </penguins>

2. Place these jar files in the lib directory in the same directory as Main.java:

 dom4j-1.6.1.jar jaxen-1.1.1.jar

3. Compile the program and run it from the terminal:

 javac -cp .:./lib/* Main.java java -cp .:./lib/* Main

4. To interpret the conclusion:

 eric@defiant ~/code/java/run04 $ javac -cp .:./lib/* Main.java eric@defiant ~/code/java/run04 $ java -cp .:./lib/* Main foo.moo: value inside cupcake foo.baz: value inside montana done

5. What just happened?

It uses Java version 1.7.0 and imports the dom4j library version 1.6.1, as well as the jaxen 1.1.1 support library. It imports the user-created XML document. He then parses it using SAXReader into a document type. It uses the selectNodes (string) method to capture the PieHole xml tag. For each PieHole xml tag, it will grab the cupcake and montan tags and put them in the Foo class. In the end, he prints what was inside Foo.

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