未知的抽象架构类型

Question

根据axtavt的答案，这几乎可以肯定是Notebean和NoteBean之间的命名问题。 这里有没有一个特定的约定要遵循，只是普通的骆驼案？

我相信我已经更新了实体中的@NamedQuery注释，并且正在使用控制器中的注释，并且名称看起来匹配，但我仍然收到有关架构的相同错误，我无法获得太多信息。

JPA 控制器：

package net.bounceme.dur.nntp.controller;
import java.util.*;
import java.util.logging.Logger;
import javax.mail.Message;
import javax.persistence.*;
import javax.swing.DefaultListModel;
import net.bounceme.dur.nntp.model.NoteBean;
public class NotesController {
    private static final long serialVersionUID = 1L;
    private static final Logger LOG = Logger.getLogger(NotesController.class.getName());
    private Message message;
    private List<NoteBean> notes = new ArrayList<NoteBean>();
    private DefaultListModel defaultListModel = new DefaultListModel();
    private EntityManagerFactory emf;
    private EntityManager em;
    private String PERSISTENCE_UNIT_NAME = "nntpPU";
    public NotesController() {
        emf = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
        em = emf.createEntityManager();
        LOG.info("entity manager made???" + em.isOpen());
        populateList();
    }
    private void populateList() {
        LOG.info("open?" + em.isOpen());
        em.getTransaction().begin();
        LOG.info("trying to populate.....");
        //Query q = em.createQuery("SELECT n FROM NoteBean n WHERE n.id = :id");
        Query q = em.createNamedQuery("NoteBean.findAll");
        LOG.info(q.toString());
        List results = q.getResultList();
        em.getTransaction().commit();
        setNotes(results);
        DefaultListModel dlm = new DefaultListModel();
        for (NoteBean n : getNotes()) {
            dlm.addElement(n);
        }
        setDefaultListModel(dlm);
    }
    public Message getMessage() {
        return message;
    }
    public void addNote(NoteBean noteBean) {
        LOG.info(noteBean.toString());
        em.getTransaction().begin();
        em.persist(noteBean);
        em.getTransaction().commit();
        populateList();
    }
    public void setMessage(Message message) {
        this.message = message;
    }
    private List<NoteBean> getNotes() {
        return notes;
    }
    private void setNotes(List<NoteBean> notes) {
        this.notes = notes;
    }
    public DefaultListModel getDefaultListModel() {
        return defaultListModel;
    }
    public void setDefaultListModel(DefaultListModel defaultListModel) {
        this.defaultListModel = defaultListModel;
    }
}

实体：

package net.bounceme.dur.nntp.model;
import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
import javax.xml.bind.annotation.XmlRootElement;
@Entity
@Table(name = "NOTEBEAN", catalog = "nntp", schema = "")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "NoteBean.findAll", query = "SELECT n FROM NoteBean n"),
    @NamedQuery(name = "NoteBean.findById", query = "SELECT n FROM Notebean n WHERE n.id = :id"),
    @NamedQuery(name = "NoteBean.findByStamp", query = "SELECT n FROM Notebean n WHERE n.stamp = :stamp"),
    @NamedQuery(name = "NoteBean.findByNote", query = "SELECT n FROM Notebean n WHERE n.note = :note")
})
public class NoteBean implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @Basic(optional = false)
    @Column(name = "ID", nullable = false)
    private Long id;
    @Column(name = "STAMP")
    @Temporal(TemporalType.DATE)
    private Date stamp;
    @Column(name = "NOTE", length = 255)
    private String note;
    public NoteBean() {
    }
    public NoteBean(Long id) {
        this.id = id;
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public Date getStamp() {
        return stamp;
    }
    public void setStamp(Date stamp) {
        this.stamp = stamp;
    }
    public String getNote() {
        return note;
    }
    public void setNote(String note) {
        this.note = note;
    }
    @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 NoteBean)) {
            return false;
        }
        NoteBean other = (NoteBean) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }
    @Override
    public String toString() {
        return "net.bounceme.dur.nntp.model.Notebean[ id=" + id + " ]";
    }
}

运行时错误：

init:
Deleting: /home/thufir/NetBeansProjects/SwingNNTP/build/built-jar.properties
deps-jar:
Updating property file: /home/thufir/NetBeansProjects/SwingNNTP/build/built-jar.properties
Compiling 2 source files to /home/thufir/NetBeansProjects/SwingNNTP/build/classes
warning: [options] bootstrap class path not set in conjunction with -source 1.5
Note: /home/thufir/NetBeansProjects/SwingNNTP/src/net/bounceme/dur/nntp/controller/NotesController.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 warning
compile:
run:
May 03, 2012 7:23:05 AM net.bounceme.dur.nntp.PropertiesReader getProps
INFO: NNTP.loadMessages...
May 03, 2012 7:23:06 AM net.bounceme.dur.nntp.controller.MessagesEnum <init>
INFO: starting controller..
[TopLink Info]: 2012.05.03 07:23:10.319--ServerSession(10922033)--TopLink, version: Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))
Exception in thread "AWT-EventQueue-0" Local Exception Stack: 
Exception [TOPLINK-8034] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.EJBQLException
Exception Description: Error compiling the query [NoteBean.findByNote: SELECT n FROM Notebean n WHERE n.note = :note]. Unknown abstract schema type [Notebean].
    at oracle.toplink.essentials.exceptions.EJBQLException.unknownAbstractSchemaType(EJBQLException.java:494)
    at oracle.toplink.essentials.internal.parsing.ParseTreeContext.classForSchemaName(ParseTreeContext.java:163)
    at oracle.toplink.essentials.internal.parsing.SelectNode.getClassOfFirstVariable(SelectNode.java:366)
    at oracle.toplink.essentials.internal.parsing.SelectNode.getReferenceClass(SelectNode.java:354)
    at oracle.toplink.essentials.internal.parsing.ParseTree.getReferenceClass(ParseTree.java:463)
    at oracle.toplink.essentials.internal.parsing.ParseTree.adjustReferenceClassForQuery(ParseTree.java:103)
    at oracle.toplink.essentials.internal.parsing.EJBQLParseTree.populateReadQueryInternal(EJBQLParseTree.java:127)
    at oracle.toplink.essentials.internal.parsing.EJBQLParseTree.populateQuery(EJBQLParseTree.java:108)
    at oracle.toplink.essentials.internal.ejb.cmp3.base.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:219)
    at oracle.toplink.essentials.queryframework.EJBQLPlaceHolderQuery.processEjbQLQuery(EJBQLPlaceHolderQuery.java:111)
    at oracle.toplink.essentials.internal.sessions.AbstractSession.processEJBQLQueries(AbstractSession.java:2059)
    at oracle.toplink.essentials.internal.sessions.AbstractSession.processEJBQLQueries(AbstractSession.java:2046)
    at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:724)
    at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:604)
    at oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:280)
    at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:229)
    at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:93)
    at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:126)
    at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:120)
    at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:91)
    at net.bounceme.dur.nntp.controller.NotesController.<init>(NotesController.java:23)
    at net.bounceme.dur.nntp.gui.Detail.<init>(Detail.java:20)
    at net.bounceme.dur.nntp.gui.NewFrame.initComponents(NewFrame.java:30)
    at net.bounceme.dur.nntp.gui.NewFrame.<init>(NewFrame.java:17)
    at net.bounceme.dur.nntp.gui.NewFrame$2.run(NewFrame.java:62)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
BUILD SUCCESSFUL (total time: 10 seconds)

仅供参考，mysql 控制台输出：

mysql> describe nntp.NOTEBEAN;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| ID    | bigint(20)   | NO   | PRI | NULL    |       |
| STAMP | date         | YES  |     | NULL    |       |
| NOTE  | varchar(255) | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
mysql> 
mysql> select * from nntp.NOTEBEAN;
Empty set (0.04 sec)
mysql> 

Answer 1

实体

类的名称（因此，用于查询的实体的默认逻辑名称）是NoteBean，而堆栈跟踪抱怨Notebean。

因此，您应该在查询中使用NoteBean而不是Notebean：

@NamedQuery(name = "Notebean.findById", 
    query = "SELECT n FROM NoteBean n WHERE n.id = :id")