Xquery to mask CreditCard number

declare function local:maskString($input as xs:string, $numClearDigits as xs:int)

as xs:string{

let $len := fn:string-length($input)

let $maskLen := $len - $numClearDigits

let $clearText := fn:substring($input, $maskLen+1)

let $mask := fn:string-join (

(for $i in (1 to $maskLen) return "X", $clearText)

,'')

return

$mask

};

Detect Java method name from code

http://www.rgagnon.com/javadetails/java-0420.html

JDK1.4

public class MyTest {

public static void main(String args[]) {

new MyTest().doit();

}

public void doit() {

System.out.println

(new Exception().getStackTrace()[0].getMethodName());

}

}

The output

doit

JDK1.5

While the above snippet is not bad, it is expensive since we need to create an Exception.

With JDK1.5, a new technique is available.

public class Test {

public static void main(String args[]) {

trace(Thread.currentThread().getStackTrace());

new Test().doit();

trace(Thread.currentThread().getStackTrace());

}

public void doit() {

trace(Thread.currentThread().getStackTrace());

doitagain();

}

public void doitagain() {

trace(Thread.currentThread().getStackTrace());

}

public static void trace(StackTraceElement e[]) {

boolean doNext = false;

for (StackTraceElement s : e) {

if (doNext) {

System.out.println(s.getMethodName());

return;

}

doNext = s.getMethodName().equals("getStackTrace");

}

}

}

Output

main

doit

doitagain

main