Java Generics 简明教程

Java Generics - No Exception

不允许泛型类直接或间接扩展 Throwable 类。

A generic class is not allowed to extend the Throwable class directly or indirectly.

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

//The generic class Box<T> may not subclass java.lang.Throwable
class Box1<T> extends Throwable {}

不允许方法捕获类型参数的实例。

A method is not allowed to catch an instance of a type parameter.

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) {
         // ...
   }
}

类型参数允许在 throws 子句中。

Type parameters are allowed in a throws clause.

class Box<T extends Exception>  {
   private int t;

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

   public int get() {
      return t;
   }
}