1.JPA双向映射取值问题解决办法

1）两个class entity：InboundNodeEntity 和InboundNodeDetailEntity 省略get ,set方法，并且这里的常量是定义在接口中的

@Entity
@Table(name=InboundNodeDbConstants.INBOUND_NODE_TABLE_NAME)
public class InboundNodeEntity implements Serializable
{

    /**  
     * serialVersionUID: Serial version UUID for InboundNodeEntity  
     * @see
     */
    private static final long serialVersionUID = 8875248360699928223L;

    @Id
    @GeneratedValue(generator = InboundNodeDbConstants.INBOUND_NODE_UUID_GENERATOR_NAME)
    @Column(name = InboundNodeDbConstants.GENERATOR_UUID_NAME)
    private String guid;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name=InboundNodeDbConstants.INBOUND_NODE_TYPE_GUID, nullable = false)
    private InboundType inboundType;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_NODE_GUID)
    private String nodeCode;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_CARDINALITY)
    private String cardinality;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_LEVEL)
    private int level;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_TABLE)
    private String tableName;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_IS_RULE_RELEVANT)
    private boolean ruleRelevant;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_RULE_OBJECT_NAME)
    private String ruleObjectName;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_ENABLED)
    private boolean enable;

    @Column(name=InboundNodeDbConstants.INBOUND_NODE_DESCRIPTION)
    private String description;

    @OneToMany(cascade={CascadeType.ALL}, mappedBy="inboundNode")
    private Set inboundNodeDetails = new HashSet12345678910111213141516171819202122232425262728293031323334353637383940414243444546

@Entity@Table(name = InboundNodeDetailDbConstant.TABLE_INBOUND_NODE_DETAIL)public class InboundNodeDetailEntity implements Serializable{

    private static final long serialVersionUID = 1L;    @Id
    @GeneratedValue(generator = "system-uuid")    @Column(name = InboundNodeDetailDbConstant.GUID)    private String guid;    @ManyToOne(fetch = FetchType.LAZY)    @JoinColumn(name = InboundNodeDetailDbConstant.NODE_GUID, nullable = false)    private InboundNodeEntity inboundNode;    @Column(name = InboundNodeDetailDbConstant.ELEMENT_CODE)    private String elementCode;    @Column(name = InboundNodeDetailDbConstant.DATA_TYPE_CODE)    private String dataTypeCode;    @Column(name = InboundNodeDetailDbConstant.IS_MANDATORY)    private boolean isMandatory;    @Column(name = InboundNodeDetailDbConstant.IS_RULERELEVANT)    private boolean isRuleRelevant;    @Column(name = InboundNodeDetailDbConstant.TABLE_NAME)    private String tableName;    @Column(name = InboundNodeDetailDbConstant.COLUM_NNAME)    private String columnName;    @Column(name = InboundNodeDetailDbConstant.IS_ENABLED)    private boolean isEnabled;    @Column(name = InboundNodeDetailDbConstant.IS_ALTERNETIVEKEY)    private boolean isAlternativeKey;    @Column(name = InboundNodeDetailDbConstant.IS_PARENT_KEY)    private boolean isParentKey;    @Column(name = InboundNodeDetailDbConstant.DESCRIPTION)    private String description;    @OneToMany(cascade = {CascadeType.ALL}, mappedBy = "inboundNodeDetailEntity")    private Set<InboundContentEntity> inboundContentEntity;
}12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849

2)controller层去调用

@GetMapping(value = "/nodeDetail/all")    public List<InboundNodeDetailEntityDto> getAllDetails()
    {        return nodeDetailService.getAllDetails();
    }12345

3）service层，这里要通过DTO去打断这个互相取值的关联，这样就不会出现一直在取值的问题了！

@Autowired
   private InboundNodeDetailEntityRepository nodeDetailRepository;

@Override
    public List<InboundNodeDetailEntityDto> getAllDetails()
    {
        List<InboundNodeDetailEntityDto> inboundNodeDetailEntities = new ArrayList<>();

        for (InboundNodeDetailEntity inboundNodeDetailEntity : nodeDetailRepository.findAll())
        {
            InboundNodeDetailEntityDto inboundNodeDetailEntity2 = new InboundNodeDetailEntityDto();
            List<InboundNodeDetailEntityParam> inboundNodeDetailEntityParams = new ArrayList<>();
            InboundNodeDetailEntityParam inboundNodeDetailEntityParam = new InboundNodeDetailEntityParam();
            inboundNodeDetailEntity2.setNodeGUID(inboundNodeDetailEntity.getInboundNode().getNodeCode());
            inboundNodeDetailEntity2.setGuid(inboundNodeDetailEntity.getGuid());
            inboundNodeDetailEntityParam.setAlternetiveKey(inboundNodeDetailEntity.getAlternativeKey());
            inboundNodeDetailEntityParam.setColumnName(inboundNodeDetailEntity.getColumnName());
            inboundNodeDetailEntityParam.setDataTypeCode(inboundNodeDetailEntity.getDataTypeCode());
            inboundNodeDetailEntityParam.setDescription(inboundNodeDetailEntity.getDescription());
            inboundNodeDetailEntityParam.setElementCode(inboundNodeDetailEntity.getElementCode());
            inboundNodeDetailEntityParam.setEnable(inboundNodeDetailEntity.getEnabled());
            inboundNodeDetailEntityParam.setMandatory(inboundNodeDetailEntity.getMandatory());
            inboundNodeDetailEntityParam.setParentKey(inboundNodeDetailEntity.getParentKey());
            inboundNodeDetailEntityParam.setRuleRelevant(inboundNodeDetailEntity.getRuleRelevant());
            inboundNodeDetailEntityParam.setTableName(inboundNodeDetailEntity.getTableName());
            inboundNodeDetailEntityParams.add(inboundNodeDetailEntityParam);
            //inboundNodeDetailEntity2.setInboundNodeDetailEntityParams(inboundNodeDetailEntityParams);
            inboundNodeDetailEntities.add(inboundNodeDetailEntity2);
        }
        return inboundNodeDetailEntities;
    }12345678910111213141516171819202122232425262728

4）Repository层

@Repositorypublic interface InboundNodeDetailEntityRepository extends JpaRepository<InboundNodeDetailEntity, String>
{

    List<InboundNodeDetailEntity> findAll();    //List<InboundNodeDetailEntity> save(List<InboundNodeDetailEntity> inboundNodeDetailEntities);

    @SuppressWarnings("unchecked")
    InboundNodeDetailEntity save(InboundNodeDetailEntity inboundNodeDetailEntity);

    @Query(value = "select ine from InboundNodeDetailEntity ine where ine.inboundNode.nodeCode = ?1 and ine.elementCode = ?2")    List<InboundNodeDetailEntity> findByNodeGuidAndElementCode(String nodeGuid, String elementCode);

    @Query(value = "select ine from InboundNodeDetailEntity ine join ine.inboundNode inNode where inNode.inboundType.typeCode=?1 and ine.inboundNode.nodeCode=?2")    List<InboundNodeDetailEntity> findByTypeCodeAndNodeCode(String typeCode, String nodeCode);
    @Query(value = "select * from \"268073BE12C74139B231A938DA1AD6EE\".\"com.sap.ems.db.integration.data::InboundMapping.NodeElement\" element join \"268073BE12C74139B231A938DA1AD6EE\".\"com.sap.ems.db.integration.data::InboundMapping.Node\" node on element.\"NodeGUID\"=node.\"GUID\" WHERE ((\"NodeGUID\" = ?1) AND (\"IsAlternativeKey\" = true)) order by node.\"Level\" desc ",nativeQuery=true)    List<InboundNodeDetailEntity> findAlternativeKeyByNodeGUID(String nodeGUID);
}12345678910111213141516171819

文章标签： Java spring-data-jpa

来源：https://blog.csdn.net/u012874209/article/details/74295079