Re: [mat-dev] means for decode java.lang.Throwable#backtrace value to st

["Kevin Grigorenko" <kevin.grigorenko@xxxxxxxxxx>]

Hi, you can write
a query to extract the stacktrace array: https://wiki.eclipse.org/MemoryAnalyzer/Extending_Memory_Analyzer

Example (needs
testing, recursion for inner exceptions, etc.):

importorg.eclipse.mat.inspections.collectionextract.CollectionExtractionUtils;
importorg.eclipse.mat.query.IQuery;
importorg.eclipse.mat.query.IResult;
importorg.eclipse.mat.query.annotations.Argument;
importorg.eclipse.mat.query.annotations.Category;
importorg.eclipse.mat.query.annotations.Help;
importorg.eclipse.mat.query.annotations.Name;
importorg.eclipse.mat.query.results.TextResult;
importorg.eclipse.mat.snapshot.ISnapshot;
importorg.eclipse.mat.snapshot.model.IObject;
importorg.eclipse.mat.snapshot.registry.ClassSpecificNameResolverRegistry;
importorg.eclipse.mat.util.IProgressListener;

@Name("Extract
Stack")
@Category("My
Extensions/JDK")
@Help("If
available, extract out a stack.\n\n")
publicclassStackExtractor implementsIQuery
{
    @Argument(isMandatory
= true)
    publicIObject object;

    @Argument
    publicISnapshot snapshot;

    @Argument(isMandatory
= false)
    publicString field;

    publicIResult execute(IProgressListener listener)
throwsException
    {
     
  StringBuilder sb= newStringBuilder();

     
  IObject stackHolder= snapshot.getObject(object.getObjectId());

     
  String[] potentialFields= newString[] { "stack",
field};

     
  IObject stackList= null;

     
  for(String potentialField: potentialFields)
     
  {
     
      if(potentialField== null)
     
          continue;

     
      stackList= (IObject) stackHolder.resolveValue(potentialField);

     
      if(stackList!= null)
     
          break;
     
  }

     
  if(stackList!= null)
     
  {
     
      booleanfoundAny= false;
     
      for(IObject frame: CollectionExtractionUtils.extractList(stackList))
     
      {
     
          String output= ClassSpecificNameResolverRegistry.resolve(frame);
     
          if(output!= null)
     
          {
     
              foundAny= true;
     
              sb.append("  
at " + output+ "<br
/>");
     
          }
     
      }
     
      if(!foundAny)
     
      {
     
          sb.append("Stack
empty or unresolvable");
     
      }
     
  }
     
  else
     
  {
     
      sb.append("Stack
field not found");
     
  }

     
  returnnewTextResult(sb.toString(),
true);
    }
}

--
Kevin Grigorenko
IBM WebSphere Application Server SWAT




From:
       "Илья
Ермолин" <ermolinis@xxxxxxxxx>
To:
       mat-dev@xxxxxxxxxxx
Date:
       08/27/2019
04:05 AM
Subject:
       [EXTERNAL]
Re: [mat-dev] means for decode java.lang.Throwable#backtrace value  
     to stacktrace
Sent
by:        mat-dev-bounces@xxxxxxxxxxx

---

Hi!

First of all - thanks for great product
for java heap dumps analize!
It's very cool tool that help me and
my colleges alot!

My question is: a get Exception in heap
dump - witch indicate place of aquire of db connectcion (c3p0 db pool),
but this exceptino doesn't contain fillled stackTrace
field, just backtrace reference to object array with some strange
data without descriptions.

I'm allrady search in java code how do
this staff filled, but this path leads to native calls...
Is there namual / description / example
of decoding this sctructure? 

-- 
С Уважением,
Ермолин Илья

Ermolin Ilya

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