如何用instanceof关键字来显示Object类？

解决方法

这个例子让displayObjectClass()方法来显示类，传递到这个方法的对象作为参数。

import java.util.ArrayList;
import java.util.Vector;

public class Main {

public static void main(String[] args) {
   Object testObject = new ArrayList();
      displayObjectClass(testObject);
   }
   public static void displayObjectClass(Object o) {
      if (o instanceof Vector)
      System.out.println("Object was an instance 
      of the class java.util.Vector");
      else if (o instanceof ArrayList)
      System.out.println("Object was an instance of 
      the class java.util.ArrayList");
      else
      System.out.println("Object was an instance of the " 
      + o.getClass());
   }
}

结果

上面的代码示例将产生以下结果。

Object was an instance of the class java.util.ArrayList