java.lang.ClassCastException : JobEntity cannot be cast to JobExcerpt (using Spring Data Projections)

Question

使用 JobExcerpt 使用投影获取实体类 JobEntity 的特定字段。

JobEntity类:https://pastebin.com/GPeQDiRp

JobExcerpt 类:

@Projection(
        name = "jobProjection",
        types = { JobEntity.class })
public interface JobExcerpt {
    Long getId();

    JobEntity.Status getStatus();

    List<BatchEntity> getBatches();

    Date getCreatedOn();

    Long getRetailerId();
}

非常简单JobExcerptRepository类:

@RepositoryRestResource(excerptProjection = JobExcerpt.class)
public interface JobExcerptRepository extends JpaRepository<JobEntity, Long> {

    JobExcerpt findByIdAndRetailerId(Long jobId, Long retailerId);

}

失败的代码行:

JobExcerpt jobExcerpt = jobExcerptRepository.findByIdAndRetailerId(jobId, retailerId);

问题是...这行代码中没有可见的(强制转换)类似运算符。应该不会显示吧？

堆栈跟踪: https://pastebin.com/iNG8h5dn

Answer 1

您似乎返回了一份工作摘录投影。这就是你得到 ClassCastException 的原因。应该是这样的。

@RepositoryRestResource(excerptProjection = JobExcerpt.class)
public interface JobExcerptRepository extends JpaRepository<JobEntity, Long> {

    JobEntity findByIdAndRetailerId(Long jobId, Long retailerId);

}

JobEntity jobEntity = jobExcerptRepository.findByIdAndRetailerId(jobId, retailerId);