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自定义两个exception类，编写一段程序使用这两个类，从标准输入读入字符串，当字符串为空时抛出一个exception当字符串包含阿拉伯数字时抛出另一个exception 捕获exception-Two custom exception class, write a program using these two classes, read the standard input string, the string is empty when thrown exception when a