Hibernate EntityManager找不到对象（NoResultException），但对象在DB中

Question

我们正在使用服务层类来执行hibernate entitymanager操作，比如查找或持久化实体到我们的mysql数据库。我们运行集成测试（10000次），对数据库执行持久化，在第二步中，我们要查找此实体并更新实体的列（＆＃39;状态＆＃39;）。问题是，两个操作都是独立的，意味着什么：

1. 创建实体并坚持
2. 通过命名查询找到此特定实体并更新

有时，随机重复（1000,3500,6000）后，命名查询找不到实体，但我们在调试和获取NoResultException时看到实体在数据库中。

以下是我们的示例代码：

的persistence.xml

<persistence>
    <persistence-unit name="GDCT_PU" transaction-type="RESOURCE_LOCAL">

        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

        <!-- the JNDI data source -->
        <!--<non-jta-data-source>java:comp/env/jdbc/testDS</non-jta-data-source>-->

        <class>com.ikea.hrms.gdct.persistence.config.domain.Sequence</class>
        <class>com.ikea.hrms.gdct.persistence.config.domain.Journal</class>

        <properties>
        <!-- if this is true, hibernate will print (to stdout) the SQL it executes,
                so you can check it to ensure it's not doing anything crazy -->

        <!-- since most database servers have slightly different versions of the
            SQL, Hibernate needs you to choose a dialect so it knows the subtleties of
            talking to that server -->
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>

            <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/DB_RU_PT"/>

            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>

            <property name="hibernate.connection.username" value="dbru_pt"/>
            <property name="hibernate.connection.password" value="peterkloeppel1234"/>

            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.release_mode" value="on_close"/>

            <!-- JDBC connection pool (use the built-in) -->
            <property name="hibernate.connection.pool_size" value="100" />
            <property name="org.hibernate.flushMode" value="COMMIT"/>

        <!-- this tell Hibernate to update the DDL when it starts, very useful
            for development, dangerous in production -->
            <property name="hibernate.hbm2ddl.auto" value="create"/>
        </properties>
    </persistence-unit>
</persistence>

SequenceService.java

public static synchronized Sequence findOne(String personnelAreaCode, String documentType, String documentCreationDate, int seqNumber) {
    logger.info("Find one specific Sequence.");

    Sequence sequence = null;

    try {
        checkEM();

        if (EMFGlobal.getInstance().getLock().tryLock(10, TimeUnit.SECONDS)) {
            logger.info("Find one: " + personnelAreaCode + "-" + documentCreationDate + "-" + seqNumber + "-" + documentType);
            Query query = em.createNamedQuery(
                    "Sequence.findOne", Sequence.class);

            sequence = (Sequence) query
                    .setParameter("personalAreaCode", personnelAreaCode)
                    .setParameter("documentType", documentType)
                    .setParameter("documentCreationDate", documentCreationDate)
                    .setParameter("seqNumber", seqNumber)
                    .getSingleResult();
        }
    }
    catch(NoResultException nre) {
        logger.error(nre);
    }
    catch (InterruptedException e) {
        e.printStackTrace();
    }
    catch (JDBCConnectionException jdbcConnectionExc) {
        logger.debug("Could not prepare Statement Sequence.findOne");
        jdbcConnectionExc.printStackTrace();
    }
    catch (Exception e) {
        logger.error(e);
    }
    finally {
        disconnectEntityManager();
        EMFGlobal.getInstance().getLock().unlock();
    }

    return sequence;
}


public static synchronized void persistSequence(Sequence sequence) {
    // persist with state "Created"
    try {
        Sequence tmpSequence = SequenceService.findOne(sequence.getPersonalAreaCode(), sequence.getDocumentType(), sequence.getDocumentCreationDate(), sequence.getSeqNumber());

        if (EMFGlobal.getInstance().getLock().tryLock(10, TimeUnit.SECONDS)) {
            checkEM();
            em.getTransaction().begin();

            if (tmpSequence == null) {
                em.persist(sequence);
            } else {
                em.merge(sequence);
            }

            em.flush();
            em.getTransaction().commit();
        }
    } catch (org.hibernate.PersistentObjectException e) {
        logger.debug("Persisting sequence number went wrong. Probably problems with EntityManager.", e);
    } catch (InterruptedException e) {
        logger.error(e);
    } finally {
        disconnectEntityManager();
        EMFGlobal.getInstance().getLock().unlock();
    }
}


private synchronized static void checkEM() {
    logger.info("Init Entity Manager.");
    if (em == null || !em.isOpen()) {
        em = EMFGlobal.getInstance().getEm();
    } else {
        logger.info("EntityManager checked. EM is open and not null!");
    }
}

/**
 * Disconnecting EntityManager used by this class.
 */
private static synchronized void disconnectEntityManager() {
    logger.info("Disconnecting the EntityManager.");
    if (em != null) {
        em.clear();
        if (em.isOpen()) {
            em.close();
        }
        em = null;
    }
}

SequenceTest.java

public void testGenerateApprove() {
    Sequence s = null;
    for (int i = 1; i < 10000; i++) {
        try {
            s = SequenceNumberManager.generateNewSequence("\\021", "002", "141123");
            logger.error("During generateNewSequence for: \\021, 002, 141123");
        } catch (Exception e) {
            e.printStackTrace();
        }

        try {
            SequenceNumberManager.approveSequence(s);
        } catch (Exception e) {
            logger.error("During approveSequences for sequence: " + s.toString());
            e.printStackTrace();
        }
    }
}

SequenceNumberManager.java

public static synchronized Sequence generateNewSequence(final String personalArea, final String form, final Date date) throws Exception {
    String personnelAreaCode = Constants.getPersonnelAreaCode().get(personalArea);

    String documentType = Constants.getformIdToDocType().get(form);
    if (documentType == null) {
        documentType = "";
    }

    SimpleDateFormat sdf = new SimpleDateFormat("yyMMdd");

    final char separator1 = '-';

    final String documentCreationDate = sdf.format(date);

    final char separator2 = separator1;

    logger.info("Getting next highest sequence number.");
    final int sequenceNumber = getNextSequenceNumber(personnelAreaCode, documentType, documentCreationDate);

    final char separator3 = separator1;

    Sequence sequence = new Sequence(personnelAreaCode, separator1, documentCreationDate, separator2,
            sequenceNumber, separator3, documentType);

    sequence.setFormNumber(form);

    Sequence seq = SequenceService.findOne(sequence.getPersonalAreaCode(), sequence.getDocumentType(), sequence.getDocumentCreationDate(), sequenceNumber);

    if (seq == null) {
        SequenceService.persistSequence(sequence);
    } else {
        logger.error("TAKING AN OLD SEQUENCE NUMBER!!!");
        return seq;
    }

    return sequence;
}


public static synchronized void approveSequence(Sequence sequence) throws Exception {
        String sequenceStr = sequence.toString();
        // check if approved
        if (sequence.getState().equalsIgnoreCase("Created")) {
            // set state to approved
            sequence.setState("Approved");

            java.util.Date persistingDate = new java.util.Date();
            java.sql.Date sqlDate = new java.sql.Date(persistingDate.getTime());
            sequence.setPersistingDate(sqlDate);

            SequenceService.persistSequence(sequence);

        } else if (sequence.getState().equalsIgnoreCase("Approved")) {
            logger.error("Sequence: " + sequenceStr + " is already approved. Please generate a new Sequence number.");
            throw new Exception("Sequence: " + sequenceStr
                    + " is already approved. Please generate a new Sequence number.");
        }

}

EMFGlobal.java

public class EMFGlobal {
    private static Logger logger = Logger.getLogger(ReportingManager.class);

    private static EntityManagerFactory emf;
    private EntityManager em;
    private ReentrantLock lock;

    public void initEntityManagerFactory() {
        logger.info("Initializing the EntityManagerFactory for persistence unit GDCT_PU");
        if(emf == null || !emf.isOpen()) {
            emf = Persistence.createEntityManagerFactory("GDCT_PU");
        }
    }

    public void destroyEntityManagerFactory() {
        if(emf != null) {
            if(emf.isOpen()) {
                emf.close();
            }
            emf = null;
        }
    }


    private static EMFGlobal instance = null;

    private EMFGlobal() {
        initEntityManagerFactory();
    }

    public static EMFGlobal getInstance() {
        if (EMFGlobal.instance == null) {
            EMFGlobal.instance = new EMFGlobal();
        }
        return EMFGlobal.instance;
    }

    public EntityManagerFactory getEmf() {
        initEntityManagerFactory();
        return emf;
    }

    public EntityManager getEm() {
        if(emf == null) {
            initEntityManagerFactory();
        }
        if(em == null || !em.isOpen()) {
            em = emf.createEntityManager();
        }
        return em;
    }

    public Lock getLock() {
        if(lock == null) {
            lock = new ReentrantLock();
        }
        return lock;
    }
}

Sequence.java

@Entity(name = "sequence")
@NamedQueries(value = {
        @NamedQuery(name = "Sequence.findByPersonalAreaCodeAndDocumentTypeAndDocumentCreationDate",
                query = "SELECT s FROM sequence s WHERE s.personalAreaCode = :personalAreaCode AND s.documentType = :documentType AND s.documentCreationDate = :documentCreationDate"),
        @NamedQuery(name = "Sequence.findAll",
                query = "SELECT s FROM sequence s"),
        @NamedQuery(name = "Sequence.findOne",
                query = "SELECT s FROM sequence s WHERE s.personalAreaCode = :personalAreaCode AND s.documentType = :documentType AND s.documentCreationDate = :documentCreationDate AND s.seqNumber = :seqNumber"),
        @NamedQuery(name = "Sequence.getNextSequenceNumber",
                query = "SELECT s FROM sequence s WHERE s.seqNumber=(SELECT max(s.seqNumber) FROM sequence s WHERE s.personalAreaCode = :personalAreaCode AND s.documentType = :documentType AND s.documentCreationDate = :documentCreationDate) AND s.personalAreaCode = :personalAreaCode AND s.documentType = :documentType AND s.documentCreationDate = :documentCreationDate")
})
public class Sequence implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int seqId;
    private String personalAreaCode;
    @Column(nullable = false, length = 1)
    private char separator1;
    @Column(nullable = false, length = 6)
    private String documentCreationDate; // format: yyMMdd
    @Column(nullable = false, length = 1)
    private char separator2;
    @Column(nullable = false)
    private int seqNumber;
    @Column(nullable = false, length = 1)
    private char separator3;
    @Column(nullable = false)
    private String documentType;

    @Column(nullable = false)
    private String state;
    private Date persistingDate;
    @Column(nullable = false)
    private String formNumber;


    public Sequence() {
        // no-args constructor required by JPA spec
        // this one is protected since it shouldn't be used directly
    }

    /**
     * Constructs Sequence with state "Created".
     *
     * @param personalAreaCode     Personnel Area Code (PAC, e.g. RSO).
     * @param separator1           Separator between PAC and DCD.
     * @param documentCreationDate Document Creation Date (DCD).
     * @param separator2           Separator between DCD and SN.
     * @param seqNumber            Sequence count Number (SN).
     * @param separator3           Separator between SN and DT.
     * @param documentType         Document Type (DT).
     */
    public Sequence(String personalAreaCode, char separator1, String documentCreationDate, char separator2, int seqNumber, char separator3, String documentType) {
        this.personalAreaCode = personalAreaCode;
        this.separator1 = separator1;
        this.separator2 = separator2;
        this.seqNumber = seqNumber;
        this.separator3 = separator3;
        this.documentType = documentType;
        this.documentCreationDate = documentCreationDate;
        this.state = "Created";
    }

    public int getSeqId() {
        return seqId;
    }

    public void setSeqId(int seqId) {
        this.seqId = seqId;
    }

    public String getPersonalAreaCode() {
        return personalAreaCode;
    }

    public void setPersonalAreaCode(String personalAreaCode) {
        this.personalAreaCode = personalAreaCode;
    }

    public char getSeparator1() {
        return separator1;
    }

    public void setSeparator1(char separator1) {
        this.separator1 = separator1;
    }

    public char getSeparator2() {
        return separator2;
    }

    public void setSeparator2(char separator2) {
        this.separator2 = separator2;
    }

    public int getSeqNumber() {
        return seqNumber;
    }

    public void setSeqNumber(int seqNumber) {
        this.seqNumber = seqNumber;
    }

    public char getSeparator3() {
        return separator3;
    }

    public void setSeparator3(char separator3) {
        this.separator3 = separator3;
    }

    public String getDocumentType() {
        return documentType;
    }

    public void setDocumentType(String documentType) {
        this.documentType = documentType;
    }

    public String getDocumentCreationDate() {
        return documentCreationDate;
    }

    public void setDocumentCreationDate(String documentCreationDate) {
        this.documentCreationDate = documentCreationDate;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public Date getPersistingDate() {
        return persistingDate;
    }

    public void setPersistingDate(Date persistingDate) {
        this.persistingDate = persistingDate;
    }

    public String getFormNumber() {
        return formNumber;
    }

    public void setFormNumber(String formNumber) {
        this.formNumber = formNumber;
    }

    @Override
    public String toString() {
        return this.getPersonalAreaCode() + this.getSeparator1() + this.getDocumentCreationDate() + this.getSeparator2()
                + this.getSeqNumber() + this.getSeparator3() + this.getDocumentType();
    }

    @Override
    public boolean equals(Object o) {
        if(o instanceof Sequence) {
            Sequence seq = (Sequence) o;
            return this.toString().equals(seq.toString());
        }
        else {
            return false;
        }
    }
}

我们希望有人可以帮助我们。我们还尝试了很多东西，比如在每次交易之前创建EntityManagerFactory和EntityManager，然后关闭它，但它变得更糟。感谢您提供任何帮助或建议。