Override is not an annotation type 问题解决

博主在同一个包下创建了名为Override的类,此前测试时未报错,但使用Override注解时出现问题,意识到这是一个低级错误。

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错误提示
检查后发现同一个包下我创建了一个Override的类
在这里插入图片描述
之前测试Override,随便创建了一个类名,当时没报错,使用Override注解时出现问题
错误很低级。。。

1. The SecurityManager class for JVM check methods can be defined differently based on context because different contexts may have different security requirements and restrictions. For example, a web application may need to restrict access to certain resources, while a desktop application may not have the same restrictions. 2. The identifier T in the declaration of the method sort represents a generic type parameter that can be replaced with any type when the method is called. For example, if we have an array of integers, we can call the sort method like this: ``` Integer[] arr = {3, 1, 4, 1, 5, 9, 2, 6, 5, 3}; Comparator<Integer> c = Comparator.naturalOrder(); Collections.sort(arr, c); ``` 3. The notation <? super T> in the declaration of sort means that the Comparator can accept any type that is a superclass of T. For example, if we have a class Animal and a subclass Dog, we can use a Comparator that accepts any superclass of Dog to sort an array of Dogs: ``` Dog[] dogs = ...; Comparator<Animal> c = ...; Collections.sort(dogs, c); ``` 4. An anonymous inner class in Java is a class that is defined and instantiated at the same time, without a separate class definition. For example, we can define an anonymous inner class to implement an interface and pass it as an argument to a method: ``` Runnable r = new Runnable() { public void run() { System.out.println("Hello, world!"); } }; r.run(); ``` 5. The same example using a lambda expression would look like this: ``` Runnable r = () -> System.out.println("Hello, world!"); r.run(); ``` 6. You might prefer to use an anonymous class instead of a lambda expression when you need to define a class that has additional behavior or state beyond the method being called. You might prefer to use a lambda expression when you only need to define a single method and want to keep the code more concise. 7. (Auto)boxing and (auto)unboxing in Java refer to the automatic conversion between primitive types and their corresponding object wrapper types. For example, an int can be automatically boxed to an Integer, and an Integer can be automatically unboxed to an int. 8. The annotation @Override in Java indicates that a method is intended to override a method in a superclass or interface. Adding this annotation can help catch errors at compile time and make the code more readable. 9. Wildcards in Java are used in generic programming to allow a generic type to accept any type that meets a certain criteria. For example, a List<? extends Number> can accept a List of any subclass of Number. 10. Bounded wildcards in Java restrict the types that can be used with a generic type parameter. For example, a List<? extends Number> can only accept types that are subclasses of Number, while a List<? super Integer> can accept types that are superclasses of Integer. An example of using a bounded wildcard would be: ``` public static double sum(List<? extends Number> list) { double total = 0.0; for (Number n : list) { total += n.doubleValue(); } return total; } ```
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