java11-exceptions-creating-exceptions-without-stacktrace

preface

• it could be valuable to take a look at: https://github.com/mtumilowicz/java11-exceptions-throwing-exceptions-is-expensive
• we could create exception without stacktrace by:
  • using dedicated constructor

    protected Exception(String message, Throwable cause,
                        boolean enableSuppression,
                        boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
    

  • overriding fillInStackTrace()

    public synchronized Throwable fillInStackTrace() {
        if (stackTrace != null ||
            backtrace != null /* Out of protocol state */ ) {
            fillInStackTrace(0);
            stackTrace = UNASSIGNED_STACK;
        }
        return this;
    }
    
    private native Throwable fillInStackTrace(int dummy);
    

project description

We will show how to create exception without stacktrace:

1. constructor approach

   class ExceptionWithoutStackTrace extends RuntimeException {
       ExceptionWithoutStackTrace() {
           super(null, null, false, false);
       }
   }
   

   and test:

   var exception = new ExceptionWithoutStackTrace();
   
   assertEquals(0, exception.getStackTrace().length);
   

2. fillInStackTrace approach

   class ExceptionWithOverriddenFillInStackTrace extends RuntimeException {
   
       @Override
       public synchronized Throwable fillInStackTrace() {
           return this;
       }
   }
   

   and test:

   var exception = new ExceptionWithOverriddenFillInStackTrace();
   
   assertEquals(0, exception.getStackTrace().length);