无法在类上找到适当的构造函数

Question

我有一个 JPQL 查询，它只需要获取两个字段，一个整数和一个列表值。这里我创建了一个 Dto 并提到了需要获取的字段。

//定义所有变量

 query = new StringBuilder();
 query.append(ReposJPQL.GET_INCIDENTS);
 q = em.createQuery(query.toString());
 result = q.getResultList();

哪里查询，

GET_INCIDENTS = "SELECT DISTINCT searchDto ("
            + "ih.Id,  ih.logs )"
            + "FROM Hdr ih left join ih.logs sl";

searchDto

public class SearchDto implements Serializable {

    private static final long serialVersionUID = 1L;

    private Integer ID
    private List<IncidentStatusLogDto> statusLogs;

    public SearchDto () {
    }

    public SearchDto (Long incidentId, List<IncidentStatusLogDto> statusLogs) {
        super();
        this.incidentId = incidentId;
        this.statusLogs = statusLogs;
    }

}

HDR 实体

@Entity
@Table(name="TB_HDR")
public class IncidentHdr implements Serializable {
    private static final long serialVersionUID = 1L;


    private Id;
    @OneToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE}, fetch = FetchType.LAZY,  mappedBy="incidentHdr")
    @JsonManagedReference
    private List<Log> logs;

//getters and setters

}

这里我根据需要在searchDto中添加了构造函数，仍然抛出异常。

no appropriate constructor in class: SearchDto]
org.hibernate.hql.internal.ast.DetailedSemanticException: Unable to locate appropriate constructor on class SearchDto]. Expected arguments are: long, java.util.Collection

当我尝试仅使用 Id 作为值并删除它工作的列表时。

Answer 1

您在 SearchDTO 类中有几个错误：

1. private Integer ID 中缺少分号应该是private Integer ID;
2. 您试图在构造函数中设置this.incidentId = incidentId;，但您没有定义变量。

由于我不知道你是否错过了它，或者你想用变量ID替换它，我的解决方案是：

public class SearchDto implements Serializable {

    private static final long serialVersionUID = 1L;

    private Integer ID;
    private Long incidentId;
    private List<IncidentStatusLogDto> statusLogs;

    public SearchDto () {
    }

    public SearchDto (Long incidentId, List<IncidentStatusLogDto> statusLogs) {
        super();
        this.incidentId = incidentId;
        this.statusLogs = statusLogs;
    }

}