java exception class,Java-ClassCastException

“ClassCastException”消息指示了Java代码正在尝试将对象转换为错误的类。在来自Java Concept of Day的这个例子中，运行以下程序：package com;

class A

{

int i = 10;

}

class B extends A

{

int j = 20;

}

class C extends B

{

int k = 30;

}

public class ClassCastExceptionDemo

{

public static void main(String[] args)

{

A a = new B(); //B type is auto up casted to A type

B b = (B) a; //A type is explicitly down casted to B type.

C c = (C) b; //Here, you will get class cast exception

System.out.println(c.k);

}

}

导致以下错误：Exception in thread “main” java.lang.ClassCastException: com.B cannot be cast to com.C

at com.ClassCastExceptionDemo.main(ClassCastExceptionDemo.java:23)

Java代码将创建一个类和子类的层次结构。为了避免“ClassCastException”错误，请确保新类型属于正确的类或其父类之一。如果使用泛型，则编译代码时可能会捕获这些错误。

阅读此教程以了解如何修复“ClassCastException”的Java软件错误。(@java_concept)