学习问题记录(4) -- 异常

import java.util.EmptyStackException;
import java.util.Stack;

class A{
    int v = 6;
    public int getV() {
        return v;
    }
}

public class ExcpOp {
    public static void Arithmetic() {
        int a = 6, b = 0;
        try{
            int c = a / b;
        } catch (ArithmeticException ae) {
            System.out.println(ae.getClass().getName()+" has been throw");
        } finally {
            System.out.println("ArithmeticEp is over!\n");
        }
    }

    public static void NullPointer() {

        try {
            A a = null;
            a.getV();
        } catch (NullPointerException npe) {
            System.out.println(npe.getClass().getName()+" has been throw");
        } finally {
            System.out.println("NullPointer is over！\n");
        }
    }

    public static void EmptyStack() {
        Stack s = new Stack();

        try{
            s.push(5);
            s.pop();
            System.out.println("Pop 1");
            s.pop();
            System.out.println("Pop 2");
        } catch (EmptyStackException ese) {
            System.out.println(ese.getClass().getName()+" has been throw");
        } finally {
            System.out.println("EmptyStack is over！\n");
        }
    }

    public static void IndexOutOfBounds() {
        int[] a = new int[3];
        for (int i = 0; i<3 ; i++ ) {
            a[i] = i;
        }
        try{
            System.out.println(a[4]);
        } catch (IndexOutOfBoundsException ioe) {
            System.out.println(ioe.getClass().getName()+" has been throw");
        } finally {
            System.out.println("EmptyStack is over！\n");
        }
    }

    public static void NegativeArraySize() {
        try{
            int[] a = new int[-3];
        } catch (NegativeArraySizeException nase) {
            System.out.println(nase.getClass().getName()+" has been throw");
        } finally {
            System.out.println("NegativeArraySize is over！\n");
        }
    }

    public static void main(String[] args) {
        ExcpOp.Arithmetic();
        ExcpOp.EmptyStack();
        ExcpOp.IndexOutOfBounds();
        ExcpOp.NegativeArraySize();
        ExcpOp.NullPointer();
    }

}

public class MyException extends Exception{
    MyException(String msg) {
        super(msg);
    }

    public static void Throw(int a) throws MyException {
        if(a <= 666) {
            throw new MyException(" 输入不666 ");
        }
    }

    public static void main(String[] args) {
        int a = 660;
        try{
            MyException.Throw(a);
        } catch (MyException me) {
            me.printStackTrace();
            a = 668;
        } finally {
            System.out.println("此时 a = "+a);
        }
    }
}