如果给定条件为假，如何编写注释/方面不输入方法但返回 null? [英] How to write an annotation/aspect to not enter a method but return null if a given condition is false?

问题描述

我目前有一个要求，如果给定条件为假，我需要从 100 个方法中返回 null.我正在考虑为此使用 Java Annotations 或 Spring Aspects，这样我就不必到处编写 if-else 代码块.关于我们如何使用 Java Annotations 或 Spring Aspects 做到这一点的任何想法?

I currently have a requirement where I need to return null from 100s of methods if a given condition is false. I was thinking of using Java Annotations or Spring Aspects for this so that I don't have to write that if-else block of code everywhere. Any idea as to how we can do this using Java Annotations or Spring Aspects?

任何提示都可能有帮助.

Any pointers might be helpful.

推荐答案

如果我理解正确，Spring @Conditional 注释就是你想要的.您创建了一些实现 Spring 的 Condition 接口的公共类:

If I get you correctly, Spring @Conditional annotation is what you want. You create some public class that implements Spring's Condition interface:

public class Test implements Condition {
...
}

然后你使用前面提到的注释和参数，该参数将公共类作为参数.

Then you use the forementioned annotation with the parameter which takes as an argument that public class.

@Conditional(Test.class)
public Object someMethod(boolean context){
/*and so do some logics; if the value of 'context' variable is false, you can return 
null; otherwise, just return like this*/
return new someMethodImpl1();
}

希望我有所帮助.我很高兴任何形式的更正.干杯！

Hope I helped. And I'm glad of any kind of corrections. Cheers!

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