标签：cot created ssi 转化 转换 int sys string 比较
public T cast(Object obj);
Casts an object to the class or interface represented
解释的比较笼统，意思就是将一个对象装换为类或者接口。
/** * Created by shengke on 2016/10/22. */ class A { public static void show() { System.out.println("Class A show() function"); } } class B extends A { public static void show() { System.out.println("Class B show() function"); } } public class TestCast { public static void main(String[] args) { TestCast cls = new TestCast(); Class c = cls.getClass(); System.out.println(c); Object obj = new A(); B b1 = new B(); b1.show(); // casts object A a = new A(); a = A.class.cast(b1); System.out.println(obj.getClass()); System.out.println(b1.getClass()); System.out.println(a.getClass()); } }
执行结果
class com.scot.effective.genericity.TestCast Class B show() function class com.scot.effective.genericity.A class com.scot.effective.genericity.B class com.scot.effective.genericity.B
核心为：a = A.class.cast(b1); 把a转化为了B类型，此处容易产生把b1转成A类型误解。
/** * Casts an object to the class or interface represented * by this {@code Class} object. * * @param obj the object to be cast * @return the object after casting, or null if obj is null * * @throws ClassCastException if the object is not * null and is not assignable to the type T. * * @since 1.5 */ public T cast(Object obj) { if (obj != null && !isInstance(obj)) throw new ClassCastException(cannotCastMsg(obj)); return (T) obj; }
此方法只能转换当前类型或其子类下的对象，只是简单进行强转。
标签：cot created ssi 转化 转换 int sys string 比较
原文地址：http://www.cnblogs.com/shengkejava/p/5988814.html
