When an exception is thrown, the static, compile-time type of the thrown object determines the type of the exception object.
当抛出一个表达式的时候,被抛出对象的静态编译时类型将决定异常对象的类型。
Thrown to indicate that the code has attempted to cast an object to a subclass of which it is not an instance.
该异常的抛出,表明代码企图把对象的类型转换成一个子类,而该对象并不是这个子类的实例。
If the Shared memory object cannot be found, an exception is thrown.
如果无法找到这个共享内存对象,就会抛出异常。