Question

编辑：元模型可能出现问题。当我将规范从userRoot.<String>get(User_.lastName)更改为userRoot.<String>get("lastName")时，它就可以了。

我正在尝试按lastName过滤用户。我创建了元模型类：

@StaticMetamodel(User.class)
public class User_ {
    public static volatile SingularAttribute<User, String> lastName;
}

规格类：

public class UserSpecifications {

    /**
     * Creates a specification used to find users whose last name begins with
     * the given search term. This search is case insensitive.
     * @param searchTerm
     * @return
     */
    public static Specification<User> lastNameIsLike(final String searchTerm) {

        return new Specification<User>() {
            @Override
            public Predicate toPredicate(Root<User> userRoot, CriteriaQuery<?> query, CriteriaBuilder cb) {
                String likePattern = getLikePattern(searchTerm);
                return cb.like(cb.lower(userRoot.<String>get(User_.lastName)), likePattern);
            }

            private String getLikePattern(final String searchTerm) {
                StringBuilder pattern = new StringBuilder();
                pattern.append(searchTerm.toLowerCase());
                pattern.append("%");
                return pattern.toString();
            }
        };
    }
}

userRepository实现JpaSpecificationExecutor<User>接口

现在，我应该可以使用以下内容获取已过滤（和已分页）的用户：

userRepository.findAll(lastNameIsLike(keyword), pageRequest);

但它不起作用：（

[ERROR] my.namespace.aop.logging.LoggingAspect - Exception in my.namespace.web.rest.UserResource.getList() with cause = null
java.lang.NullPointerException: null
        at org.hibernate.jpa.criteria.path.AbstractPathImpl.get(AbstractPathImpl.java:140) ~[hibernate-entitymanager-4.3.6.Final.jar:4.3.6.Final]
        at my.namespace.domain.specification.UserSpecifications$1.toPredicate(UserSpecifications.java:31) ~[classes/:na]
        at org.springframework.data.jpa.repository.support.SimpleJpaRepository.applySpecificationToCriteria(SimpleJpaRepository.java:538) ~[spring-data-jpa-1.7.1.RELEASE.jar:na]
        at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:489) ~[spring-data-jpa-1.7.1.RELEASE.jar:na]
        at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:474) ~[spring-data-jpa-1.7.1.RELEASE.jar:na]
        at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:356) ~[spring-data-jpa-1.7.1.RELEASE.jar:na]

JPA过滤数据

0 个答案: