Using Exception Trace Points

Consider these guidelines before adding exception trace points to your code:

• Use exception trace points in all methods where entry or exit trace points are specified, and in methods that catch and rethrow exceptions. Identity Manager sometimes throws exceptions in which a new exception wraps the original exception. Use the same trace level being used by the entry and exit trace points.

• Use an exception trace point if an exception is created and thrown from the current method.

• Use an exception trace point caught method if an exception is caught and handled. For example, when the exception is not thrown from the current method. This situation typically occurs when Identity Manager catches and handles the exception by placing it in a container, such as a WavesetResult, to be examined later.

• If the exception thrown from the current method is not a checked exception, which is an exception that extends java.lang.RuntimeException or java.lang.Error, the method exit point will not be traced unless other measures are taken. One way to set an exception trace point in this situation is to use a try/catch block around the critical section of the method and rethrow the exceptions that occur. In general, this means that you should use Trace.Level3 and higher when it is critical to know whether a method has succeeded or failed.

Following is an example of a simple exception trace statement. For this example, assume the following CLASS variables are declared:

private static final String CLASS = 
"com.waveset.adapter.MyResourceAdapter"; 
protected static Trace _trace = Trace.getTrace();

Example 5–4 Exception Trace Point Example

try {   
   someMethod(); 
}  catch(Exception e) {   
   _trace.throwing(_trace.ALWAYS, CLASS, METHOD, e);   
   throw e; 
}


try {   
   someMethod(); 
}  catch(Exception e) {   
   _trace.throwing(_trace.ALWAYS, CLASS, METHOD, e);   
   WavesetException we = new WavesetException(Some Message, e);   
   throw we; 
}


if (error) {   
  WavesetException e = new WavesetException(Some Error Message.; 
  _trace.throwing(_trace.LEVEL3, CLASS, METHOD, e);   
  throw e;
}

try {
   someMethod();
}  catch(Exception e) {
   _trace.caught(_trace.LEVEL1, CLASS, METHOD, e);
}
// execution continues.
someOtherMethod();