Class DiagnosticModule

java.lang.Object
com.ibm.ws.ffdc.DiagnosticModule

public class DiagnosticModule extends Object
Extend this class to create a diagnostic module to help FFDC capture and dump data for your component. Example usage:
 DiagnosticModuleForComponent dm = new DiagnosticModuleForComponent();
 if (FFDC.registerDiagnosticModule(dm, "com.ibm.ws.mycomponent.packagename") != 0)
 {
 // Diagnostic module failed to meet the criteria described above
 // Return codes :
 // 0 - DM was registered
 // 1 - A DM has already been registered with the package name
 // 2 - The DM did not meet the criteria to contain a single dump method
 // 3 - An unknown failure occured during the registration
 }
 
Any methods beginning with "ffdcDump" will be recognized by the ffdc runtime, and used for data collection. These methods should expect the following parameters:
  1. Throwable th. The encountered exception.
  2. IncidentStream is. Write captured data to this stream.
  3. Object[] others. The value of the array may be null. If not null, it contains an array of objects which the caller to the FFDC filter passed.
  4. Object callerThis. The callerThis value may be null, if the method which invoked the filter was a static method. Or if the current point of execution for the filter, does not correspond to the DM being invoked.
  5. String sourceId. The sourceId passed to the filter.
*

Method names that start with "ffdcDumpDefault" will always be called when this component is involved in an exception or error situation. These methods will be responsible for performing the default data capture for their component.

Method names that simply start with "ffdcDump" [not ffdcDumpDefault] are only called under certain conditions and are not considered part of the default data capture.

Methods that don't start with "ffdcDump", or that don't conform to the expected signature will be ignored. Setting the com.ibm.ws.ffdc.debugDiagnosticModule system property to true will cause exceptions to be thrown for malformed diagnostic module signatures.

  • Field Details

    • DEBUG_DM_PROPERTY

      public static final String DEBUG_DM_PROPERTY
      Name of property used to enable noise-making when badly formed methods are encountered when initializing a new module.
      See Also:
    • FFDC_DUMP_PREFIX

      public static final String FFDC_DUMP_PREFIX
      The prefix of ffdcdump methods (compared using toLowerCase)
      See Also:
    • FFDC_DUMP_DEFAULT_PREFIX

      public static final String FFDC_DUMP_DEFAULT_PREFIX
      The prefix of ffdcdumpdefault methods (compared using toLowerCase)
      See Also:
  • Constructor Details

    • DiagnosticModule

      public DiagnosticModule()
  • Method Details

    • getDirectives

      public String[] getDirectives()
      Return the list of directives returned by this diagnostic module.
      Returns:
      String[]
    • dumpComponentData

      public final boolean dumpComponentData(String[] input_directives, Throwable ex, IncidentStream ffdcis, Object callerThis, Object[] catcherObjects, String sourceId, String[] callStack)
      This method is invoked to instruct the diagnostic module to capture all relevant information that it has about a particular incident
      Parameters:
      input_directives - The directives to be processed for this incident
      ex - The exception that caused this incident
      ffdcis - The incident stream to be used to record the relevant information
      callerThis - The object reporting the incident
      catcherObjects - Additional objects that might be involved
      sourceId - The source id of the class reporting the incident
      callStack - The list of classes on the stack
      Returns:
      true if more diagnostic modules should be invoked after this one
    • getDataForDirectives

      public final void getDataForDirectives(String[] directives, Throwable ex, IncidentStream ffdcis, Object callerThis, Object[] catcherObjects, String sourceId)
      Invoke all the ffdcdump methods for a set of directives
      Parameters:
      directives - The list of directives to be invoked
      ex - The exception causing the incident
      ffdcis - The incident stream on which to report
      callerThis - The object reporting the incident
      catcherObjects - Any additional interesting objects
      sourceId - The sourceid of the class reporting the problem
    • validate

      public final boolean validate()
      Validate whether the diagnostic module is correctly coded. Method can be used as a simple validation of a components diagnostic module. The information printed can be used during the development of the DM.
      Returns:
      true; if the system property "com.ibm.ws.ffdc.debugDiagnosticModule" is set, then some validation will be performed on the diagnostic module.
    • stopProcessingException

      public final void stopProcessingException()
      Inform this base class (and the diagnostic engine) that no more diagnosis information is required for this incident