我做了一个 @NamedNativeQuery 并将其附加到一个实体 "医生 "上，在同一个实体上我附加了一个 "医生"。@SqlResultSetMapping 它将查询结果的列，映射到一个专门制作的POJO类的构造函数。这个查询也连接到一个JPA方法，它驻留在同一个实体的仓库中。
然而，我一直得到一个错误信息，说无法找到合适的构造函数，就像 @SqlResultSetMapping 或POJO构造函数不同步。(堆栈痕迹在底部)
我的实体。@NamedNativeQuery 和 @SqlResultSetMapping:
我直接在DB上尝试查询，得到了预期的结果，所以我只是写了select子句。
@Entity
@NamedNativeQuery(
name =
"Doctor.findFreeExaminationTimes", // name of the JPA method in entity's repository (definition below)
query =
"SELECT on_date AS onDate, LAG(to_time, 1, '00:00') OVER mojWindow AS fromTime, from_time AS toTime " +
"...",
resultSetMapping = "freeTimesByDoctorId" // name of the mapping below
)
@SqlResultSetMapping(
name = "freeTimesByDoctorId", // result set mapping name
classes = @ConstructorResult(
targetClass = DoctorAvailabilityResponse.class, // my POJO class (definition below)
columns = { // order and types are the same as in the select clause above and the POJO constructor below
@ColumnResult(name = "onDate", type = java.sql.Date.class),
@ColumnResult(name = "fromTime", type = java.sql.Time.class),
@ColumnResult(name = "toTime",type = java.sql.Time.class)
}
)
)
public class Doctor extends User {...}
我在'targetClass'下的@ConstructorResult中提到的POJO类有一个构造函数，它的参数顺序、数量和类型都是在'columns'下指定的。
我的POJO类，它应该被映射到查询的结果中。
public class DoctorAvailabilityResponse {
final private java.sql.Date onDate;
final private java.sql.Time fromTime;
final private java.sql.Time toTime;
public DoctorAvailabilityResponse(java.sql.Date onDate, java.sql.Time fromTime, java.sql.Time toTime) {
this.onDate = onDate;
this.fromTime = fromTime;
this.toTime = toTime;
}
// getters
}
我的仓库
@RepositoryRestResource
public interface DoctorRepository extends UserRepository<Doctor> {
// JPA method mapped to the named native query above
List<DoctorAvailabilityResponse> findFreeExaminationTimes(@Param("doctorId") Long doctorId);
}
但是当测试这个JPA方法的时候，我得到了一个异常信息 "无法找到合适的构造函数"。
我的测试。
@SpringBootTest
public class DoctorTests {
@Autowired
private DoctorRepository doctorRepository;
private final Logger LOGGER = LoggerFactory.getLogger(this.getClass());
@Test
public void shouldReturnDoctorAvailability() {
// Exception thrown here
List<DoctorAvailabilityResponse> freeTimes = doctorRepository.findFreeExaminationTimes(4L);
LOGGER.info(freeTimes.toString());
}
}
我不明白为什么会出现这种情况 有没有办法在维护JPA仓库方法的同时，手动将这个结果集映射到POJO？
堆栈跟踪。
org.springframework.dao.InvalidDataAccessApiUsageException: Could not locate appropriate constructor on class : com.example.isaproj.isa_projekat_2019.Model.DTO.DoctorAvailabilityResponse; nested exception is java.lang.IllegalArgumentException: Could not locate appropriate constructor on class : com.example.isaproj.isa_projekat_2019.Model.DTO.DoctorAvailabilityResponse
at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:374)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:256)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:528)
...
...
Caused by: java.lang.IllegalArgumentException: Could not locate appropriate constructor on class : com.example.isaproj.isa_projekat_2019.Model.DTO.DoctorAvailabilityResponse
at org.hibernate.loader.custom.ConstructorResultColumnProcessor.resolveConstructor(ConstructorResultColumnProcessor.java:92)
at org.hibernate.loader.custom.ConstructorResultColumnProcessor.performDiscovery(ConstructorResultColumnProcessor.java:45)
at org.hibernate.loader.custom.CustomLoader.autoDiscoverTypes(CustomLoader.java:494)
at org.hibernate.loader.Loader.processResultSet(Loader.java:2333)
at org.hibernate.loader.Loader.getResultSet(Loader.java:2289)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:2045)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:2007)
at org.hibernate.loader.Loader.doQuery(Loader.java:953)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354)
at org.hibernate.loader.Loader.doList(Loader.java:2810)
at org.hibernate.loader.Loader.doList(Loader.java:2792)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2624)
at org.hibernate.loader.Loader.list(Loader.java:2619)
at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:338)
at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:2137)
at org.hibernate.internal.AbstractSharedSessionContract.list(AbstractSharedSessionContract.java:1134)
at org.hibernate.query.internal.NativeQueryImpl.doList(NativeQueryImpl.java:173)
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1526)
at org.hibernate.query.Query.getResultList(Query.java:165)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:409)
at com.sun.proxy.$Proxy212.getResultList(Unknown Source)
at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:126)
at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:88)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:154)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:142)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:618)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:605)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:353)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
... 73 more
安全性检查和替代方法
为了进行理智的检查，我删除了 @SqlResultSetMapping，在这种情况下，查询应该返回一个'Object[]'值的列表，然后我测试了该数组中的每一个单独的值来检查它的类型，它显示我的类型是我假设的'java.sql.Date'和'java.sql.Time'两次，它们三个都是按照预期的顺序，（Date、Time、Time），这与我的POJO类的构造函数参数的顺序相匹配。
我的实体和namedNativeQuery。
@Entity
@NamedNativeQuery(
name =
"Doctor.findFreeExaminationTimes",
query =
"SELECT on_date AS onDate, LAG(to_time, 1, '00:00') OVER mojWindow AS fromTime, from_time AS toTime " +
"..."
)
public class Doctor extends User {...}
我的存储库有一个新的返回类型。
@RepositoryRestResource
public interface DoctorRepository extends UserRepository<Doctor> {
List<Object[]> findFreeExaminationTimes(@Param("doctorId") Long doctorId);
}
我的测试
@SpringBootTest
public class DoctorTests {
@Autowired
private DoctorRepository doctorRepository;
private final Logger LOGGER = LoggerFactory.getLogger(this.getClass());
@Test
public void shouldReturnDoctorAvailability() {
// Exception thrown here
List<DoctorAvailabilityResponse> freeTimes = doctorRepository.findFreeExaminationTimes(4L);
freeTimes.stream().forEach((ft) -> {
// Values are in expected order and of expected types
String classNameOnDate = ft[0].getClass().toString(); // java.sql.Date
String classNameFromTime = ft[1].getClass().toString(); // java.sql.Time
String classNameToTime = ft[1].getClass().toString(); // java.sql.Time
// I suppose the mapping mechanism is supposed to do something like this, but fails for some reason
DoctorAvailabilityResponse dar = new DoctorAvailabilityResponse((Date)ft[0], (Time)ft[1], (Time)ft[2]);
});
LOGGER.info(freeTimes.toString());
}
}
运行这个测试可以完美地工作，这应该表明问题出在@SqlResultSetMapping或POJO类中。
我希望得到任何反馈。谢谢
我不得不改变在 @SqlResultSetMapping 和我的POJO类的构造函数中。
改变了 @SqlResultSetMapping
@SqlResultSetMapping(
name = "freeTimesByDoctorId",
classes = @ConstructorResult(
targetClass = DoctorAvailabilityResponse.class,
columns = {
@ColumnResult(name = "onDate", type = String.class),
@ColumnResult(name = "fromTime", type = String.class),
@ColumnResult(name = "toTime",type = String.class)
}
)
)
更改POJO类构造函数
public DoctorAvailabilityResponse(String onDate, String fromTime, String toTime) {
this.onDate = Date.valueOf(onDate);
this.fromTime = Time.valueOf(fromTime);
this.toTime = Time.valueOf(toTime);
}
然而，这本身并没有解决我的问题，因为我得到了一个如上所述的休眠异常，并解决了这个问题。在这个问题上. 根据这个答案，我也改变了我的版本库，并增加了一个注释。
改变了版本库
@RepositoryRestResource
public interface DoctorRepository extends UserRepository<Doctor> {
@Query(nativeQuery = true) // This is added
List<DoctorAvailabilityResponse> findFreeExaminationTimes(@Param("doctorId") Long doctorId);
}
现在一切都正常了，虽然问题是为什么没有。@SqlResultSetMapping 地图 java.sql.* 类型到构造函数中。
@ConstructorResult 并不能很好地与 java.sql.Date.class 或 java.sql.Time.class 类型。解决您的问题的方法是使用 String.class 而不是将字符串值转换为DateTime，然后在 DoctorAvailabilityResponse的构造函数