Tcl Blend Exceptions

Below is some Tcl Blend code that will get the Java error stack from an exception and return it as a string to Tcl.

# Print the most recent Java stack trace
# Here's an example:
# Create a String
#   set s [java::new {String java.lang.String} "123"]
# Try to get a character beyond the end of the array
#   catch {$s charAt 4} err
#   puts "The error was:\n$err"
#   puts "The stack was:\n[jdkStackTrace]"
proc jdkStackTrace {} {
    global errorCode errorInfo
    if { [string match {JAVA*} $errorCode] } {
	set exception [lindex $errorCode 1]
	set stream [java::new java.io.ByteArrayOutputStream]
	set printWriter [java::new \
		{java.io.PrintWriter java.io.OutputStream} $stream]
	$exception {printStackTrace java.io.PrintWriter} $printWriter
	$printWriter flush

	puts "[$exception getMessage]"
	puts "    while executing"
	puts "[$stream toString]"
	puts "    while executing"
    }
    puts $errorInfo
}

These Tcl procs and others are included in util.tcl

Below is an example:

% source util.tcl
% set s [java::new {String java.lang.String} "123"]
java0x1
% catch {$s charAt 4} err
1
% puts "The error was:\n$err"
The error was:
java.lang.StringIndexOutOfBoundsException: String index out of range: 4
% puts "The stack was:\n[jdkStackTrace]"
String index out of range: 4
    while executing
java.lang.StringIndexOutOfBoundsException: String index out of range: 4
	at java.lang.Throwable.(Compiled Code)
	at java.lang.Exception.(Compiled Code)
	at java.lang.RuntimeException.(Compiled Code)
	at java.lang.IndexOutOfBoundsException.(Compiled Code)
	at java.lang.StringIndexOutOfBoundsException.(Compiled Code)
	at java.lang.String.charAt(Compiled Code)
	at tcl.lang.reflect.PkgInvoker.invokeMethod(Compiled Code)
	at tcl.lang.JavaInvoke.call(Compiled Code)
	at tcl.lang.JavaInvoke.callMethod(Compiled Code)
	at tcl.lang.ReflectObject.cmdProc(Compiled Code)
	at tcl.lang.Parser.evalObjv(Compiled Code)
	at tcl.lang.Parser.eval2(Compiled Code)
	at tcl.lang.Interp.eval(Compiled Code)
	at tcl.lang.Interp.eval(Compiled Code)
	at tcl.lang.CatchCmd.cmdProc(Compiled Code)
	at tcl.lang.Parser.evalObjv(Compiled Code)
	at tcl.lang.Parser.eval2(Compiled Code)
	at tcl.lang.Interp.eval(Compiled Code)
	at tcl.lang.ConsoleEvent.processEvent(Compiled Code)
	at tcl.lang.Notifier.serviceEvent(Compiled Code)
	at tcl.lang.Notifier.doOneEvent(Compiled Code)
	at tcl.lang.Shell.main(Compiled Code)

    while executing
java.lang.StringIndexOutOfBoundsException: String index out of range: 4
    while executing
"$s charAt 4"
The stack was:

%

Last updated: 10/09/05, cxh at eecs