Spring中的@AliasFor标签

淩亂°似流年 2022-05-21 10:50 98阅读 0赞

@AliasFor标签：来给注解的属性起别名，让使用注解时，更加的容易理解，必须成对使用

很多源码中都有类似的例子

@Retention(RetentionPolicy.RUNTIME)
    	@Target({})
    	@interface Filter {
    
    		/**
    		 * The type of filter to use.
    		 * <p>Default is {@link FilterType#ANNOTATION}.
    		 * @see #classes
    		 * @see #pattern
    		 */
    		FilterType type() default FilterType.ANNOTATION;
    
    		/**
    		 * Alias for {@link #classes}.
    		 * @see #classes
    		 */
    		@AliasFor("classes") Class<?>[] value() default {};
    
    		/**
    		 * The class or classes to use as the filter.
    		 * <p>The following table explains how the classes will be interpreted
    		 * based on the configured value of the {@link #type} attribute.
    		 * <table border="1">
    		 * <tr><th>{@code FilterType}</th><th>Class Interpreted As</th></tr>
    		 * <tr><td>{@link FilterType#ANNOTATION ANNOTATION}</td>
    		 * <td>the annotation itself</td></tr>
    		 * <tr><td>{@link FilterType#ASSIGNABLE_TYPE ASSIGNABLE_TYPE}</td>
    		 * <td>the type that detected components should be assignable to</td></tr>
    		 * <tr><td>{@link FilterType#CUSTOM CUSTOM}</td>
    		 * <td>an implementation of {@link TypeFilter}</td></tr>
    		 * </table>
    		 * <p>When multiple classes are specified, <em>OR</em> logic is applied
    		 * — for example, "include types annotated with {@code @Foo} OR {@code @Bar}".
    		 * <p>Custom {@link TypeFilter TypeFilters} may optionally implement any of the
    		 * following {@link org.springframework.beans.factory.Aware Aware} interfaces, and
    		 * their respective methods will be called prior to {@link TypeFilter#match match}:
    		 * <ul>
    		 * <li>{@link org.springframework.context.EnvironmentAware EnvironmentAware}</li>
    		 * <li>{@link org.springframework.beans.factory.BeanFactoryAware BeanFactoryAware}
    		 * <li>{@link org.springframework.beans.factory.BeanClassLoaderAware BeanClassLoaderAware}
    		 * <li>{@link org.springframework.context.ResourceLoaderAware ResourceLoaderAware}
    		 * </ul>
    		 * <p>Specifying zero classes is permitted but will have no effect on component
    		 * scanning.
    		 * @since 4.2
    		 * @see #value
    		 * @see #type
    		 */
    		@AliasFor("value") Class<?>[] classes() default {};
    
    		/**
    		 * The pattern (or patterns) to use for the filter, as an alternative
    		 * to specifying a Class {@link #value}.
    		 * <p>If {@link #type} is set to {@link FilterType#ASPECTJ ASPECTJ},
    		 * this is an AspectJ type pattern expression. If {@link #type} is
    		 * set to {@link FilterType#REGEX REGEX}, this is a regex pattern
    		 * for the fully-qualified class names to match.
    		 * @see #type
    		 * @see #classes
    		 */
    		String[] pattern() default {};
    
    	}