Re: [mdr-users] NullPointerException

Hello,

	You have just load the UML metamodel (M2). Now, you have to instantiate 
this metamodel to create your UML model (M1). Try to do something like this:

repository.createExtent(name, modelPackage);

	Where "name" is the name of your UML model and "modelPackage" is the M2 
package ("UML" ou "Activity_Graphs", for example).

	Leo

Cheng yong wrote:
> Hello, Leo and other MDR experts,
>  
> I'm still litte confused about using MDR to create one activty graph in 
> XMI.
>  
> I tried to do following things:
>  
>             // connect to the repository
>             MDRepository repository = 
> MDRManager.getDefault().getDefaultRepository();
>             ModelPackage modelPackage=null;
>           
>             // Init Repository with UML 1.4 metamodel (M2)
>             try{
>             modelPackage = (ModelPackage)repository.createExtent("TEST 
> MODEL");
>             URL xmiSpemMetamodel = 
> this.getClass().getResource("01-02-15_Diff.xml");
>             System.out.println( xmiSpemMetamodel.getContent().toString());
>             XMIReader xmiReader = 
> XMIReaderFactory.getDefault().createXMIReader();
>             xmiReader.read(xmiSpemMetamodel.toString(), 
> modelPackage);         
>             } catch(Exception e){
>                 e.printStackTrace();
>             }
>  
> According to the Leo's clues, I should init the activity model extent 
> (M1), I found the MofPackage with the name "Activity_Graphs", but I 
> don't know which resource file I should provide as metamodel. The 
> metamodel is already included in 01-02-15_Diff.xml, istn't it? Why 
> should do it again?
>  
> I'm sorry to bother you with such questions. I hope that you can help me.
>  
> regards
>  
> lucia
> 
> 
> */Leonardo Gresta Paulino Murta <[email protected]>/* wrote:
> 
>     Hello,
> 
>     You need to load your metamodel first... Take a look on the following
>     code (it uses SPEM metamodel, but the idea is almost the same for UML -
>     In the case of UML you will need to search for a package named Model
>     and
>     instantiate it...):
> 
>     // Init Repository with SPEM metamodel (M2)
>     ModelPackage modelPackage =
>     (ModelPackage)repository.createExtent(METAMODEL_EXTENT);
>     URL xmiSpemMetamodel = this.getClass().getResource(SPEM_METAMODEL);
>     xmiReader.read(xmiSpemMetamodel.toString(), modelPackage);
> 
>     // Init the SPEM model extent (M1)
>     Iterator iterator =
>     modelPackage.getMofPackage().refAllOfClass().iterator();
>     while (iterator.hasNext()) {
>     MofPackage mofPackage = (MofPackage)iterator.next();
>     if ("SPEM".equals(mofPackage.getName())) {
>     spemPackage = (SpemPackage)repository.createExtent(MODEL_EXTENT,
>     mofPackage);
>     URL xmiSpemModel = this.getClass().getResource(SPEM_MODEL);
>     xmiReader.read(xmiSpemModel.toString(), spemPackage);
>     break;
>     }
>     }
> 
>     Leo
> 
>     Cheng yong wrote:
>      > Hello, everyone,
>      >
>      > I'm now making my own example according to the online document
>     and try
>      > to figure out how the MDR works. Now I have got an
>     NullPointerException
>      > Error. Can anyone help me?
>      >
>      > What I did is as following:
>      > 1. NetBeans IDE 3.5.1: imported Metadata UML 1.4
>     (01-02-15_Diff.xml) and
>      > generated the JMI Interfaces.
>      > 2. Eclipse 3.1: created a new project, added all .jar files which
>     I can
>      > find in the installation folder, imported all generated files.
>      > 3. Eclipse 3.1: created a new demo class,
>      >
>      > package demo;
>      > import java.io.OutputStream;
>      > import java.util.Iterator;
>      > import org.netbeans.api.mdr.MDRManager;
>      > import org.netbeans.api.mdr.MDRepository;
>      > import org.netbeans.api.xmi.XMIWriterFactory;
>      > import org.omg.uml.*;
>      > import org.omg.uml.behavioralelements.activitygraphs.*;
>      > public class Demo {
>      >
>      > public static void main(String[] args) {
>      >
>      > OutputStream out = null;
>      >
>      > MDRepository repository =
>      > MDRManager.getDefault().getDefaultRepository();
>      >
>      > UmlPackage extent = (UmlPackage) repository.getExtent("Projects
>      > metadata");
>      > try{
>      >
>      >
>     XMIWriterFactory.getDefault().createXMIWriter().write(out,extent,"1.2");
>      > System.out.println(out.toString());
>      > } catch(Exception e){
>      > System.out.println("ERROR!");
>      > }
>      > }
>      > }
>      > 4. Eclipse 3.1: runed the demo, got the error:
>      >
>      > java.lang.NullPointerException
>      > at
>      >
>     org.netbeans.modules.mdr.MDRManagerImpl.refreshChildren(MDRManagerImpl.java:61)
>      > at
>     org.netbeans.modules.mdr.MDRManagerImpl.init(MDRManagerImpl.java:84)
>      > at
>      >
>     org.netbeans.modules.mdr.MDRManagerImpl.getRepository(MDRManagerImpl.java:94)
>      > at
>      >
>     org.netbeans.modules.mdr.MDRManagerImpl.getDefaultRepository(MDRManagerImpl.java:105)
>      > at demo.Demo.main(Demo.java:18)
>      > Exception in thread "main"
>      >
>      > thanks
>      >
>      > Lucia
>      >
>      >
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