top.openyuan.jpa.specification.handler.impl.JoinPredicateHandler Maven / Gradle / Ivy

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package top.openyuan.jpa.specification.handler.impl;

import top.openyuan.jpa.exception.BuildSpecificationException;
import top.openyuan.jpa.specification.SpecificationPlus;
import top.openyuan.jpa.specification.handler.AbstractPredicateHandler;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.From;
import javax.persistence.criteria.Join;
import javax.persistence.criteria.Predicate;
import java.lang.annotation.Annotation;

/**
 * 构建“实体连接条件”({@code JOIN})场景的 {@link Predicate} 处理器.
 *
 * @author lzy
 * @since v1.0.0
 */
public class JoinPredicateHandler extends AbstractPredicateHandler {

    @Override
    public Class getAnnotation() {
        return top.openyuan.jpa.specification.annotation.Join.class;
    }

    @Override
    public  Predicate buildPredicate(
            CriteriaBuilder criteriaBuilder, From from, String name, Object value, Annotation annotation) {
        if (!(annotation instanceof top.openyuan.jpa.specification.annotation.Join)) {
            throw new BuildSpecificationException("【Jpa-plus 异常】使用【@Join】构建表连接时,【" + getClass().getName()
                    + ".getAnnotation()】获取到的值【" + this.getAnnotation().getName() + "】与字段使用的注解值【"
                    + annotation.getClass().getName() + "】不同");
        }

        Join subJoin = from.join(name,
                ((top.openyuan.jpa.specification.annotation.Join) annotation).joinType());
        return criteriaBuilder.and(SpecificationPlus.beanParamToPredicate(subJoin, criteriaBuilder, value)
                .toArray(new Predicate[0]));
    }

    @Override
    public Predicate buildPredicate(
            CriteriaBuilder criteriaBuilder, From from, String fieldName, Object value) {
        throw new BuildSpecificationException("本方法暂不支持.");
    }

}