com.techempower.data.annotation.Relation Maven / Gradle / Ivy

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package com.techempower.data.annotation;

import java.lang.annotation.*;

/**
 * This annotation attaches to a class that defines a CachedRelation. It is
 * required that the class also use the annotations @Left and @Right
 * to specify the Left class and Right class which describe the relationship.
 * 
 * 
 *   @Relation
 *   public class UsersToGroups
 *   {
 *     @Left
 *     public User user;
 *     
 *     @Right
 *     public Group group;
 *   }
 * 
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Relation
{
    /**
     * The database table that stores the identifiers for the related entities.
     *
     * @return the database table that stores these entities
     * @see com.techempower.cache.CachedRelation.Builder#table(String)
     */
    String table() default "";
}