java - why does ambiguity not raised for ArithmeticException parameter method -

below code executed out compilation error of ambiguity, , output "arithmeticexception". guys can u me know reason.

class test {      public static void main(string[] args) throws unknownhostexception, ioexception {         testmetod(null);     }      // overloaded method of parameter type object     private static void testmetod(object object) {         system.out.println("object");     }      // overloaded method of parameter type exception     private static void testmetod(exception e) {         system.out.println("exception");     }      // overloaded method of parameter type arithmeticexception     private static void testmetod(arithmeticexception ae) {         system.out.println("arithmeticexception");     }  } 

in cases rule match specific method. since arithmeticexception extends exception , arithmeticexception extends object, there no ambiguity: arithmeticexception more specific of others.

if add though:

private static void testmetod(string string) {     system.out.println("string"); } 

you compilation error because neither arithmeticexception extends string true, nor other way around: there no single specific parameter class.

it's important @ point happening @ compile time. once target method resolved , code compiled, call overloaded method call other method. in contrast method overriding.