DZone Snippets: trace code

JSP: Printing Java stacktraces in JSP pages

mehlam2 (Mehlam) — Wed, 18 Jun 2008 17:31:56 GMT

// This snippet shows how to view java stack traces for exceptions occurring inside jsp files.





try{

  //some code that throws an exception

}

catch(Exception e){

  // Cannot print using standard out. Cast JSP writer into a print writer.

  e.printStackTrace( new java.io.PrintWriter(out))

}

Get a String version of a stacktrace

frost137 (Douglas Wyatt) — Thu, 20 Sep 2007 21:00:14 GMT

// Get a String version of a stacktrace



    Throwable t = new Throwable();  // test code



    final Writer result = new StringWriter();

    final PrintWriter printWriter = new PrintWriter(result);

    t.printStackTrace(printWriter);

    result.toString();

Ruby - Trace Variable Global

whitetiger () — Sat, 25 Nov 2006 19:47:22 GMT

// Tracciare variabili Globali



trace_var:$variabileGlobale, proc{ print "variabileGlobale modificata al valore --> ", $variabileGlobale, " "}

get the name of the calling methos

derbumi (Michael) — Thu, 05 Oct 2006 21:21:00 GMT

caller_method_name() gets you the name of the calling method.
you could also get the line and file in which the method is called.





def caller_method_name

    parse_caller(caller(2).first).last

end



def parse_caller(at)

    if /^(.+?):(\d+)(?::in `(.*)')?/ =~ at

        file = Regexp.last_match[1]

		line = Regexp.last_match[2].to_i

		method = Regexp.last_match[3]

		[file, line, method]

	end

end