Java 泛型无界类型擦除

package com.codingdict;

public class GenericsTester {
   public static void main(String[] args) {
      Box integerBox = new Box();
      Box stringBox = new Box();

      integerBox.add(new Integer(10));
      stringBox.add(new String("Hello World"));

      System.out.printf("Integer Value :%d\n", integerBox.get());
      System.out.printf("String Value :%s\n", stringBox.get());
   }
}

class Box {
   private Object t;

   public void add(Object t) {
      this.t = t;
   }

   public Object get() {
      return t;
   }   
}