java - 在java中获取实例化类型变量

Question

我想检查泛型类的实例化类型是否具有某些属性，例如:

class Foo<T> {
  void bar () { 
    if (T instanceof Serializable)   // does not compile
      ...
  } 
}

我想知道通用信息是否在运行时完全丢失？这是否意味着没有办法完成我想做的事情？

Answer 1

And does that mean there is no way to accomplish what I would like to do?

你可以写:

class Foo<T> {
  private final Class<T> clazz;

  Foo (final Class<T> clazz) { // require creator to supply a Class<T>
    this.clazz = clazz;
    if (clazz == null) {
      throw new NullPointerException();
    }
  }

  void bar () { 
    if (Serializable.class.isAssignableFrom(clazz)) {
      ...
    }
  } 
}