java141-自定义捕捉异常

    //自定义异常类
    public class ArrayElement extends  Exception{
        public static final int MAX_NUM=1000;
        private static final String MESSAGE="集合存储元素过多";
        public ArrayElement(){
        }
        public String getMessage(){
            return MESSAGE+"最大元素限制为"+MAX_NUM;
        }
        public void printStackTrace(){
            System.err.println(MESSAGE);
            super.printStackTrace();
        }
    }

定义

    import java.util.ArrayList;
    import java.util.List;
     
    public class UseArray {
        public List<String> StoreElement(int size) throws ArrayElement{
            List<String> list=new ArrayList<>( );
            for(int i=0;i<size;i++){
                if(i>ArrayElement.MAX_NUM)
                    throw new ArrayElement();
                list.add("元素"+i);
            }
            return list;
        }
    }

测试类

    import java.util.List;
     
    //自定义异常
    public class test84 {
        public static void main(String[] args){
            UseArray uaet=new UseArray();
            try {
                List<String> list =uaet.StoreElement( 1100 );
                System.out.println( list.size() );
            }catch (ArrayElement e){
                System.out.println( e.getMessage() );
                e.printStackTrace();
            }
        }
    }

运行结果