Java泛型不允许扩展Exception和Throwable类

java泛型类进行从Exception和Throwable类扩展
 例:下面的定义方式"不会被允许"
   //The generic class InfoClass<T> may not subclass java.lang.Throwable
class InfoClass<T> extends Exception {}

//The generic class InfoClass<T> may not subclass java.lang.Throwable
class InfoClass1<T> extends Throwable {}

不允许方法捕获类型参数的实例
public static <T extends Exception, J>
   void execute(list<J> jobs) {
      try {
         for (J job : jobs) {}

         // compile-time error
         //Cannot use the type parameter T in a catch block
      } catch (T e) {
         // ...
   }
}

类型参数在throws子句中是允许的
class InfoClass<T extends Exception>  {
   private int t;

   public void add(int t) throws T {
      this.t = t;
   }

   public int get() {
      return t;
   }   
}