Xml parsing in Android, Null exception

Question

i have an xml that looks this way

<Quiz>
<Inhalt Frage="test" number="1" />
<Inhalt Frage ="test2" number=2"/> 
</Quiz>

Now, in android i want to parse this xml in that way, that the result show me the content of "Frage" for the number 2. I have tried to parse it this way, but i always get a nullexception error:

XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
XPathExpression expr= xpath.compile("//Frage[@number=2]/text()");

Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
einga= nodes.item(0).getNodeName();

Would be great, if someone could help me with this. Thank you :-)

You are trying to select the text from the node Frage which have an attribute number with the value 2. Are you familiar with Xpath expressions ? Try this link : w3schools.com/xpath/xpath_syntax.asp Try : "/Quiz/Inhalt[@number=2]@Frage" You will get test2 — Stephane Mathis
– Stephane Mathis, Commented Oct 18, 2012 at 14:13
Thank you, but When i try this, i get the error: Extra illegal tokens '@','Frage' — Basem Abdelfattah
– Basem Abdelfattah, Commented Oct 18, 2012 at 15:17
it worked this way:XPathExpression expr= xpath.compile("//Inhalt[@nummer='2']/@Frage"); — Basem Abdelfattah
– Basem Abdelfattah, Commented Oct 18, 2012 at 16:24
Right... there was a / missing before the @ in @Stephane's suggestion. In regard to learning XPath: please don't use w3schools, unless you want to have to unlearn their mistakes later. (See w3fools.com) Instead try zvon.org/xxl/XPathTutorial/General/examples.html — LarsH
– LarsH, Commented Oct 18, 2012 at 17:39
@StephaneMathis, could you make your comment into an answer? Then, this question will no longer be categorized as "unanswered", and Basem can "accept" your answer if he wants to. (And you will likely get more rep.) — LarsH
– LarsH, Commented Oct 18, 2012 at 17:41

Geobits · Accepted Answer · 2012-10-18 21:10:58Z

1

You are trying to select the text from the node Frage which have an attribute number with the value 2. Are you familiar with Xpath expressions? Try this link : http://w3schools.com/xpath/xpath_syntax.asp

Try : "//Inhalt[@number='2']/@Frage". You will get test2

edited Oct 18, 2012 at 21:10

Geobits

22.4k6 gold badges62 silver badges107 bronze badges

answered Oct 18, 2012 at 21:06

Stephane Mathis

6,6226 gold badges46 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Xml parsing in Android, Null exception

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related