Re: XPATH-Query on single document in collection

[Wolfram Horwath]

OK, now this is working as I want it. I was missing this, should have 
had a closer look into JavaDoc :-)

Thanks again!
Upayavira schrieb:
You need to query a resource, rather than a collection. Here's some 
code in Cocoon that'll do it. Check out the resourceToSAX method, and 
the associated queryToSAX() method.

http://cvs.apache.org/viewcvs.cgi/cocoon-2.1/src/blocks/xmldb/java/org/apache/cocoon/components/source/impl/XMLDBSource.java 

Upayavira
Wolfram Horwath wrote:
Maybe I'm doing it wrong, but it doesn't seem to work.
So here's what I'm doing:
I have a class XmlDB which has a method open() and query(xpath):
public void open () {
     try {
        String driver = "org.apache.xindice.client.xmldb.DatabaseImpl";
        Class c = Class.forName(driver);
        Database database = (Database) c.newInstance();
        DatabaseManager.registerDatabase(database);
        String url = protocol + dbhost + collection;
        dbCollection = DatabaseManager.getCollection(url);
     } catch (XMLDBException xmle) {
        System.err.println("XML:DB Exception occured " + 
xmle.errorCode);
     } catch (Exception e) {
        e.printStackTrace();
     }
  }

public ResourceSet query (String xpath) {
     ResourceSet rs = null;
     try {
        XPathQueryService service =
           (XPathQueryService) 
dbCollection.getService("XPathQueryService",
                                                       "1.0");
        rs = service.query(xpath);
     } catch (XMLDBException xmle) {
        xmle.printStackTrace();
     }
     return (rs);
  }

The collection I work on is /db/upro with documents having labels 
like klasse0.xml.
With collection.listResources() I try to get a list of all documents 
in the collection, to query each one afterwards.

When I try to set the collection to /db/upro/klasse0.xml for my 
following query I get a NullPointerException, when trying to query 
with /db/upro/klasse0.xml/some/more or /klasse0.xml/some/more or 
similar, on collection /db/upro, just nothing happens.

So, any hints what I am doing wrong?
Wolfram Horwath schrieb:
I wasn't aware if this was possible as it's not mentioned anywhere 
in the documentation. I thought of this possibility but wanted 
confirmation, so I'm going to try it that way.

Thanks for your help!
Wolfram
Upayavira schrieb:
Wolfram Horwath wrote:
Hi!
Is there a way to execute a XPATH-Query on only one specified 
document in a collection?


Erm. Isn't this easy? /db/collection/#//xpath does an Xpath on a 
collection, whereas /db/collection/document#//xpath does one on a 
document in a collection.

Am, I missing something?
Upayavira