JPA java.lang.IllegalArgumentException：找不到name的NamedQuery

Question

我一直在看你所有关于相关情况的帖子，但没有一篇解决我的情况。

public class TagJpaController implements Serializable {

public TagJpaController(EntityManagerFactory emf) {
    this.emf = emf;
}
private EntityManagerFactory emf = null;

public EntityManager getEntityManager() {
    return emf.createEntityManager();
}

public void create(Tag tag) throws PreexistingEntityException, Exception {
    if (tag.getSentenceTagList() == null) {
        tag.setSentenceTagList(new ArrayList<SentenceTag>());
    }
    EntityManager em = null;
    try {
        em = getEntityManager();
        em.getTransaction().begin();
        List<SentenceTag> attachedSentenceTagList = new ArrayList<SentenceTag>();
        for (SentenceTag sentenceTagListSentenceTagToAttach : tag.getSentenceTagList()) {
            sentenceTagListSentenceTagToAttach = em.getReference(sentenceTagListSentenceTagToAttach.getClass(), sentenceTagListSentenceTagToAttach.getId());
            attachedSentenceTagList.add(sentenceTagListSentenceTagToAttach);
        }
        tag.setSentenceTagList(attachedSentenceTagList);
        em.persist(tag);
        for (SentenceTag sentenceTagListSentenceTag : tag.getSentenceTagList()) {
            Tag oldTagIdOfSentenceTagListSentenceTag = sentenceTagListSentenceTag.getTagId();
            sentenceTagListSentenceTag.setTagId(tag);
            sentenceTagListSentenceTag = em.merge(sentenceTagListSentenceTag);
            if (oldTagIdOfSentenceTagListSentenceTag != null) {
                oldTagIdOfSentenceTagListSentenceTag.getSentenceTagList().remove(sentenceTagListSentenceTag);
                oldTagIdOfSentenceTagListSentenceTag = em.merge(oldTagIdOfSentenceTagListSentenceTag);
            }
        }
        em.getTransaction().commit();
    } catch (Exception ex) {
        if (findTag(tag.getId()) != null) {
            throw new PreexistingEntityException("Tag " + tag + " already exists.", ex);
        }
        throw ex;
    } finally {
        if (em != null) {
            em.close();
        }
    }
}

public void edit(Tag tag) throws IllegalOrphanException, NonexistentEntityException, Exception {
    EntityManager em = null;
    try {
        em = getEntityManager();
        em.getTransaction().begin();
        Tag persistentTag = em.find(Tag.class, tag.getId());
        List<SentenceTag> sentenceTagListOld = persistentTag.getSentenceTagList();
        List<SentenceTag> sentenceTagListNew = tag.getSentenceTagList();
        List<String> illegalOrphanMessages = null;
        for (SentenceTag sentenceTagListOldSentenceTag : sentenceTagListOld) {
            if (!sentenceTagListNew.contains(sentenceTagListOldSentenceTag)) {
                if (illegalOrphanMessages == null) {
                    illegalOrphanMessages = new ArrayList<String>();
                }
                illegalOrphanMessages.add("You must retain SentenceTag " + sentenceTagListOldSentenceTag + " since its tagId field is not nullable.");
            }
        }
        if (illegalOrphanMessages != null) {
            throw new IllegalOrphanException(illegalOrphanMessages);
        }
        List<SentenceTag> attachedSentenceTagListNew = new ArrayList<SentenceTag>();
        for (SentenceTag sentenceTagListNewSentenceTagToAttach : sentenceTagListNew) {
            sentenceTagListNewSentenceTagToAttach = em.getReference(sentenceTagListNewSentenceTagToAttach.getClass(), sentenceTagListNewSentenceTagToAttach.getId());
            attachedSentenceTagListNew.add(sentenceTagListNewSentenceTagToAttach);
        }
        sentenceTagListNew = attachedSentenceTagListNew;
        tag.setSentenceTagList(sentenceTagListNew);
        tag = em.merge(tag);
        for (SentenceTag sentenceTagListNewSentenceTag : sentenceTagListNew) {
            if (!sentenceTagListOld.contains(sentenceTagListNewSentenceTag)) {
                Tag oldTagIdOfSentenceTagListNewSentenceTag = sentenceTagListNewSentenceTag.getTagId();
                sentenceTagListNewSentenceTag.setTagId(tag);
                sentenceTagListNewSentenceTag = em.merge(sentenceTagListNewSentenceTag);
                if (oldTagIdOfSentenceTagListNewSentenceTag != null && !oldTagIdOfSentenceTagListNewSentenceTag.equals(tag)) {
                    oldTagIdOfSentenceTagListNewSentenceTag.getSentenceTagList().remove(sentenceTagListNewSentenceTag);
                    oldTagIdOfSentenceTagListNewSentenceTag = em.merge(oldTagIdOfSentenceTagListNewSentenceTag);
                }
            }
        }
        em.getTransaction().commit();
    } catch (Exception ex) {
        String msg = ex.getLocalizedMessage();
        if (msg == null || msg.length() == 0) {
            String id = tag.getId();
            if (findTag(id) == null) {
                throw new NonexistentEntityException("The tag with id " + id + " no longer exists.");
            }
        }
        throw ex;
    } finally {
        if (em != null) {
            em.close();
        }
    }
}

public void destroy(String id) throws IllegalOrphanException, NonexistentEntityException {
    EntityManager em = null;
    try {
        em = getEntityManager();
        em.getTransaction().begin();
        Tag tag;
        try {
            tag = em.getReference(Tag.class, id);
            tag.getId();
        } catch (EntityNotFoundException enfe) {
            throw new NonexistentEntityException("The tag with id " + id + " no longer exists.", enfe);
        }
        List<String> illegalOrphanMessages = null;
        List<SentenceTag> sentenceTagListOrphanCheck = tag.getSentenceTagList();
        for (SentenceTag sentenceTagListOrphanCheckSentenceTag : sentenceTagListOrphanCheck) {
            if (illegalOrphanMessages == null) {
                illegalOrphanMessages = new ArrayList<String>();
            }
            illegalOrphanMessages.add("This Tag (" + tag + ") cannot be destroyed since the SentenceTag " + sentenceTagListOrphanCheckSentenceTag + " in its sentenceTagList field has a non-nullable tagId field.");
        }
        if (illegalOrphanMessages != null) {
            throw new IllegalOrphanException(illegalOrphanMessages);
        }
        em.remove(tag);
        em.getTransaction().commit();
    } finally {
        if (em != null) {
            em.close();
        }
    }
}

public List<Tag> findTagEntities() {
    return findTagEntities(true, -1, -1);
}

public List<Tag> findTagEntities(int maxResults, int firstResult) {
    return findTagEntities(false, maxResults, firstResult);
}

private List<Tag> findTagEntities(boolean all, int maxResults, int firstResult) {
    EntityManager em = getEntityManager();
    try {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        cq.select(cq.from(Tag.class));
        Query q = em.createQuery(cq);
        if (!all) {
            q.setMaxResults(maxResults);
            q.setFirstResult(firstResult);
        }
        return q.getResultList();
    } finally {
        em.close();
    }
}

public Tag findTag(String id) {
    EntityManager em = getEntityManager();
    try {
        return em.find(Tag.class, id);
    } finally {
        em.close();
    }
}

public int getTagCount() {
    EntityManager em = getEntityManager();
    try {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        Root<Tag> rt = cq.from(Tag.class);
        cq.select(em.getCriteriaBuilder().count(rt));
        Query q = em.createQuery(cq);
        return ((Long) q.getSingleResult()).intValue();
    } finally {
        em.close();
    }
}

public Tag findTagByName(String name) {
    EntityManager em = getEntityManager();
    Tag result = null;
    try {
        TypedQuery<Tag> consultaTag = em.createNamedQuery("Tag.findByName", Tag.class);
        consultaTag.setParameter("name", name);
        result = consultaTag.getSingleResult();
    } finally {
        em.close();
    }
    return result;
}

public Tag findTagByNameAndCreateIfNotExist(String name) {
    Tag tag = findTagByName(name);
    
    if(tag == null) {
        
        try {
            tag = new Tag();
            tag.setId(UUID.randomUUID().toString());
            tag.setName(name);
            tag.setCreated(new Date());
            tag.setModified(new Date());
            
            this.create(tag);
        } catch (Exception ex) {
            
            tag = null;
            
        }
    }
    
    return tag;
}


@Entity
@Table(name = "tags")
@NamedQueries({
@NamedQuery(name = "Tag.findAll", query = "SELECT t FROM Tag t"),
@NamedQuery(name = "Tag.findById", query = "SELECT t FROM Tag t WHERE t.id = :id"),
@NamedQuery(name = "Tag.findByName", query = "SELECT t FROM Tag t WHERE t.name = :name"),
@NamedQuery(name = "Tag.findByCreated", query = "SELECT t FROM Tag t WHERE t.created = :created"),
@NamedQuery(name = "Tag.findByModified", query = "SELECT t FROM Tag t WHERE t.modified = :modified")})
public class Tag implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@Basic(optional = false)
@Column(name = "id")
private String id;
@Basic(optional = false)
@Column(name = "name")
private String name;
@Column(name = "created")
@Temporal(TemporalType.TIMESTAMP)
private Date created;
@Column(name = "modified")
@Temporal(TemporalType.TIMESTAMP)
private Date modified;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "tagId")
private List<SentenceTag> sentenceTagList;

public Tag() {
}

public Tag(String id) {
    this.id = id;
}

public Tag(String id, String name) {
    this.id = id;
    this.name = name;
}

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Date getCreated() {
    return created;
}

public void setCreated(Date created) {
    this.created = created;
}

public Date getModified() {
    return modified;
}

public void setModified(Date modified) {
    this.modified = modified;
}

public List<SentenceTag> getSentenceTagList() {
    return sentenceTagList;
}

public void setSentenceTagList(List<SentenceTag> sentenceTagList) {
    this.sentenceTagList = sentenceTagList;
}

@Override
public int hashCode() {
    int hash = 0;
    hash += (id != null ? id.hashCode() : 0);
    return hash;
}

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Tag)) {
        return false;
    }
    Tag other = (Tag) object;
    if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
        return false;
    }
    return true;
}

}

public class Facade {

private TagJpaController tagController;
private EntityManagerFactory emFactory = 
        Persistence.createEntityManagerFactory("mydatabank");

private Facade() {
    tagController = new TagJpaController(emFactory);
}

public static Facade getInstance() {
    return FacadeHolder.INSTANCE;
}



private static class FacadeHolder {

    private static final Facade INSTANCE = new Facade();
}


public Tag findTagByName(String name) {
    return tagController.findTagByName(name);
}

public Tag findTagByNameAndCreateIfNotExist(String name) {
    return tagController.findTagByNameAndCreateIfNotExist(name);
}
}

<?xml version="1.0" encoding="UTF-8"?>
    <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="mydatabank" transaction-type="RESOURCE_LOCAL">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <class>com.data.Charge</class>
        <class>com.data.Headquarter</class>
        <class>com.data.Judge</class>
        <class>com.data.JudgeCharge</class>
        <class>com.data.Matter</class>
        <class>com.data.Process</class>
        <class>com.data.Sentence</class>
        <class>com.data.SentenceImportance</class>
        <class>com.data.SentenceJudge</class>
        <class>com.data.SentenceMatter</class>
        <class>com.data.SentenceTag</class>
        <class>com.data.SentenceTrack</class>
        <class>com.data.SentenceType</class>
        <class>com.data.Tag</class>
        <class>com.data.Track</class>
        <shared-cache-mode>ALL</shared-cache-mode>
        <exclude-unlisted-classes>false</exclude-unlisted-classes>
        <properties>
          <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/mydatabank?zeroDateTimeBehavior=CONVERT_TO_NULL"/>
          <property name="javax.persistence.jdbc.user" value="root"/>
          <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver"/>
          <property name="javax.persistence.jdbc.password" value="password"/>
        </properties>
      </persistence-unit>
    </persistence>

当我调用findTagByName时，会引发异常。你能帮我吗？

Answer 1

NamedQueries必须在orm.xml文件或实体类中定义。在您的情况下，必须将实体标记定义为

@Entity
@NamedQueries({
    @NamedQuery(
        name = "Tag.findTagByName", 
        query = "SELECT t FROM Tag AS t WHERE t.name = :name")
})
public class Tag {
// Your code here
}

一旦定义了命名查询，EntityManager.GetNamedQuery（）就可以访问它。