Spring 如何自定义注解？

﹏ヽ暗。殇╰゛Y 2023-01-16 09:55 82阅读 0赞

Spring 中最简单的自定义注解的方式就是使用现有的注解，标注在自定义的注解之上，复用原注解的能力。

/**
     * 自定义注解，继承自 @Component
     * 
     * @author ConstXiong
     */
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.TYPE)
    @Documented
    @Component
    public @interface CustomComponent {
    
        String value() default "";
    }
    
    /**
     * 自定义 ComponentScan
     */
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.TYPE)
    @Documented
    @ComponentScan
    public @interface CustomComponentScan {
    
        /**
         * 别名
         */
        @AliasFor(annotation=ComponentScan.class, value="basePackages")
        String[] v() default {};
    
    }
    
    
    /**
     * 测试 Spring 自定义注解
     * 
     * @author ConstXiong
     */
    @CustomComponentScan(v="constxiong")
    public class Test {
    
        public static void main(String[] args) throws Exception {
            AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Test.class);
            System.out.println(context.getBean("u", User.class));
        }
    }

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