java - 将类类型作为参数传递

Question

我有两种这样的方法

public void updateA (Object obj) throws CommonException
{
  if ( !(obj instanceof A) )
  {
     throw new CommonException(obj);
  }
  // other codes  
}


public void updateB (Object obj) throws CommonException
{
  if ( !(obj instanceof B) )
  {
     throw new CommonException(obj);
  }
  // other codes  
}

现在我想将实例检查部分提取到一个单独的方法中。 是否可以按如下方式进行？

public void chkInstance (Object obj, Class classType) throws CommonException
{
  if ( !(obj instanceof classType) )
  {
     throw new CommonException(obj);
  }
}

Answer 1

使用Class.isInstance:

if(!(classType.isInstance(obj)) {
    // ...
}

documentation实际上是完全状态(强调我的):

Determines if the specified Object is assignment-compatible with the object represented by this Class. This method is the dynamic equivalent of the Java language instanceof operator.