com.ibm.ws.ffdc
Class DiagnosticModule

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

public class DiagnosticModule
extends java.lang.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 Summary
static java.lang.String DEBUG_DM_PROPERTY
          Name of property used to enable noise-making when badly formed methods are encountered when initializing a new module.
static java.lang.String FFDC_DUMP_DEFAULT_PREFIX
          The prefix of ffdcdumpdefault methods (compared using toLowerCase)
static java.lang.String FFDC_DUMP_PREFIX
          The prefix of ffdcdump methods (compared using toLowerCase)
 
Constructor Summary
DiagnosticModule()
           
 
Method Summary
 boolean dumpComponentData(java.lang.String[] input_directives, java.lang.Throwable ex, IncidentStream ffdcis, java.lang.Object callerThis, java.lang.Object[] catcherObjects, java.lang.String sourceId, java.lang.String[] callStack)
          This method is invoked to instruct the diagnostic module to capture all relevant information that it has about a particular incident
 void getDataForDirectives(java.lang.String[] directives, java.lang.Throwable ex, IncidentStream ffdcis, java.lang.Object callerThis, java.lang.Object[] catcherObjects, java.lang.String sourceId)
          Invoke all the ffdcdump methods for a set of directives
 java.lang.String[] getDirectives()
          Return the list of directives returned by this diagnostic module.
 void stopProcessingException()
          Inform this base class (and the diagnostic engine) that no more diagnosis information is required for this incident
 boolean validate()
          Validate whether the diagnostic module is correctly coded.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEBUG_DM_PROPERTY

public static final java.lang.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:
Constant Field Values

FFDC_DUMP_PREFIX

public static final java.lang.String FFDC_DUMP_PREFIX
The prefix of ffdcdump methods (compared using toLowerCase)

See Also:
Constant Field Values

FFDC_DUMP_DEFAULT_PREFIX

public static final java.lang.String FFDC_DUMP_DEFAULT_PREFIX
The prefix of ffdcdumpdefault methods (compared using toLowerCase)

See Also:
Constant Field Values
Constructor Detail

DiagnosticModule

public DiagnosticModule()
Method Detail

getDirectives

public java.lang.String[] getDirectives()
Return the list of directives returned by this diagnostic module.

Returns:
String[]

dumpComponentData

public final boolean dumpComponentData(java.lang.String[] input_directives,
                                       java.lang.Throwable ex,
                                       IncidentStream ffdcis,
                                       java.lang.Object callerThis,
                                       java.lang.Object[] catcherObjects,
                                       java.lang.String sourceId,
                                       java.lang.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(java.lang.String[] directives,
                                       java.lang.Throwable ex,
                                       IncidentStream ffdcis,
                                       java.lang.Object callerThis,
                                       java.lang.Object[] catcherObjects,
                                       java.lang.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