java中的类型转换的基本原则

• 子类可以转化为父类
• 类可以转化为实现的接口

 
package test;
interface TestFaceBase {
}
interface TestFace extends TestFaceBase {
}
class Base {
}
class Father extends Base {
}
public class Test extends Father implements TestFace {
 /**
  * @param args
  */
 public static void main(String[] args) {
  Test t = new Test();
  Father f = (Father) t;
  Base b = (Base) t;
  TestFace tf = (TestFace) t;
  TestFaceBase tfb = (TestFaceBase) t;
 }
}