org.springframework.data.mapping.PropertyReferenceException：没有找到类型的属性捕获

Question

我对 Spring Data 存储库有疑问。

当我部署时，我得到一个异常，这是因为 Spring Data 尝试动态派生该方法，但在 Entity 中找不到相应的属性。

如何将自定义方法放入自定义存储库中而不出现此问题？

这些是涉及的组件：

1. LocaleJpaImpl: 实体
2. LocaleJpaRepositoryClient：业务层类
3. interface LocaleJpaRepository extends JpaRepository<LocaleJpaImpl, Long>, LocaleJpaRepositoryCustom
4. interface LocaleJpaRepositoryCustom
5. LocaleJpaRepositoryImplemented implements LocaleJpaRepositoryCustom

LocaleJpaRepositoryCustom 有一个方法：

List<String> catchLanguagesCombinations() throws DAOSystemException;

（LanguagesCombinations 不是 LocaleJpaImpl 的属性。因为该动机在自定义存储库中）。

这个例外：

Caused by: org.springframework.data.mapping.PropertyReferenceException: No property languages found for type com.engine.i18n.domain.LocaleJpaImpl
at org.springframework.data.mapping.PropertyPath.<init>(PropertyPath.java:74)
at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:326)
at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:352)
at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:306)
at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:270)
at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:244)
at org.springframework.data.repository.query.parser.Part.<init>(Part.java:73)
at org.springframework.data.repository.query.parser.PartTree$OrPart.<init>(PartTree.java:180)
at org.springframework.data.repository.query.parser.PartTree$Predicate.buildTree(PartTree.java:260)
at org.springframework.data.repository.query.parser.PartTree$Predicate.<init>(PartTree.java:240)
at org.springframework.data.repository.query.parser.PartTree.<init>(PartTree.java:68)
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:57)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:90)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:162)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:68)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:280)
at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:148)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:125)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:41)
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:142)
... 33 more

---

这是相关代码：

1. LocaleJpaImpl：

import java.io.Serializable;
import javax.persistence.AttributeOverride;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;
import com.jpa.BaseEntityJpaSupport;

@Entity
@Table(name = "LOCALE")
@XmlRootElement
@AttributeOverride(name="id", column=@Column(name="LOCALE_ID"))

@NamedQueries({
    @NamedQuery(name = "Locale.findAll", query = "FROM LocaleJpaImpl l"),
    @NamedQuery(name = "Locale.findByLocaleId", query = "FROM LocaleJpaImpl l WHERE l.localeId = :localeId"),
    @NamedQuery(name = "Locale.findByLanguageCode", query = "FROM LocaleJpaImpl l WHERE l.languageCode = :languageCode")

public class LocaleJpaImpl extends BaseEntityJpaSupport implements Serializable {

private static final long serialVersionUID = 1L;

    //@Id
    //@Column(name = "LOCALE_ID")
    @Basic(optional = false)
    @NotNull
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer localeId;

    @Size(max = 2)
    @Column(name = "LANGUAGE_CODE")    
    private String languageCode;

    public LocaleJpaImpl(Integer localeId) { this.localeId = localeId; }    
    public int getLocaleId() { return localeId; }    
    public void setLocaleId(Integer localeId) { this.localeId = localeId; }      
    public String getLanguageCode() { return languageCode; }    
    public void setLanguageCode(String languageCode) { this.languageCode = languageCode; }
}

3.接口 LocaleJpaRepository

import java.util.List;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import com.engine.i18n.domain.LocaleJpaImpl;

public interface LocaleJpaRepository extends JpaRepository<LocaleJpaImpl, Long>, LocaleJpaRepositoryCustom {

    @Query("FROM LocaleJpaImpl L WHERE L.languageCode = :languageCode")
    List<LocaleJpaImpl> findLocaleByLanguageCode(@Param("languageCode") String languageCode);   

}

4.接口 LocaleJpaRepositoryCustom

import java.util.List;
import com.util.DAOSystemException;

public interface LocaleJpaRepositoryCustom {

    List<String> catchLanguagesCombinations() throws DAOSystemException;
}

5. LocaleJpaRepositoryImplemented

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import com.util.DAOSystemException;

public class LocaleJpaRepositoryImplemented implements LocaleJpaRepositoryCustom {

    @PersistenceContext(unitName = "contentEntityManagerFactory")
    private EntityManager em;

    @SuppressWarnings("unchecked")
    @Override
    public List<String> catchLanguagesCombinations() throws DAOSystemException {

        return "result";
    }
}

Answer 1

自定义存储库实现类名称应该是接口名称，它使用 Impl 扩展 JPARepositry

Answer 2

我遇到了这样的问题，我的错误是自定义存储库类的名称：

如果您的 jpa 存储库接口名称为LocaleJpaRepository，则您的新自定义接口应命名为LocaleJpaRepositoryCustom，但在方法中进行覆盖的类必须命名为LocaleJpaRepositoryImpl，如下所示：

public class LocalJpaRepositoryImpl implements LocalJpaRepositoryCustom{
@Override
   public void customMethod(){....}
}

基本上，您的自定义接口的实现类应该以您的存储库接口 (JPARepository) 的名称开头，并以“Impl”关键字结尾。