Nesting try blocks should be

performed when an exception generated within the inner try block that is not caught by a catch is propagated to the outer try block
continued up the stack trace until the exception is caught by the appropriate handler.

An example of a nested try block follows:

//Use a nested try block

class NestTrys {
public static void main (String args[ ]) {
//Here, numer is longer than denom

int numer[] = {4, 8, 16, 32, 64, 128, 256, 512};
int denom[] = {2, 0, 4, 4, 0, 8};

            try {
            //outer try block
            for(int i = 0; i < numer.length; i++) {

                         try{
                        //the inner try block
                                          System.out.println(numer[i] + "/" +
                                                                 denom[i] + " is " +
                                                                 numer[i] /denom[i]);

                        }
                        catch (ArithmeticException exc) {
                        //some code to tell the user what happened to cause the error
                        System.out.println("Can’t divide by Zero!");
                        }
             }
    }
catch (ArrayIndexOutOfBoundsException exc) {
the exception if the program tries to access an array index that doesn’t exist
//the code is specifically tailored to match the purpose of the program

System.out.println("No matching element found.");
System.out.println("Fatal error - - program terminated.");
}
}
}