Here’s an example of how to create an exception. You can extend this example as needed for your own applications. The important principle is the exeption’s mechanism, not its subject:
class PrivateException extends Exception{//constructor without parameterspublic PrivateException() {}//constructor for exception descriptionpublic PrivateException(String description) { super(description); }}class Test { public Test(){} //this method will throw a PrivateException void method1(int a ,int b) throws PrivateException { System.out.println("You called method1 !!!
"); //specify when to generate the exception if(a==b) { String description="In method "method1" a PrivateException has been generated
"+ " The "+a+" and "+b+" arguments are equal!!!
"+ " Call this method with no equal arguments."; throw new PrivateException(description); } } //this method will throw a PrivateException void method2(int a, int b)throws PrivateException { System.out.println("You called method2 !!!
"); //specify when to generate the exception if((a*b)>10) { String description="In method "method2" a PrivateException has been generated
"+ " The "+a+" * "+b+" is grater that 10 !!!
"+ " Call this method with smaller arguments."; throw new PrivateException(description); } } }public class TestPrivateException{ public static void main(String[] args) { Test t=new Test(); try{ t.method1(22,20); //NO EXCEPTION t.method2(11,23); //EXCEPTION }catch(PrivateException e) {e.printStackTrace();} }}