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How期间提供的参数列表中没有找到的查询参数富做我设置的参数为下面的查询的说法：在查询执行
实体：
package net.bounceme.dur.usenet.model;
import java.io.Serializable;
import java.util.logging.Logger;
import javax.mail.Folder;
import javax.mail.Message;
import javax.persistence.*;
import net.bounceme.dur.usenet.driver.FetchBean;
@Entity
public class Article implements Serializable {
private static final long serialVersionUID = 1L;
private static final Logger LOG = Logger.getLogger(Article.class.getName());
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column
private int messageNumber;
@ManyToOne(cascade = CascadeType.PERSIST)
private Newsgroup newsgroup;
public Article() {
}
public Article(Message message, Folder folder) {
messageNumber = message.getMessageNumber();
EntityManagerFactory emf;
EntityManager em;
emf = Persistence.createEntityManagerFactory("USENETPU");
em = emf.createEntityManager();
String ng = folder.getFullName();
Query query = em.createQuery("SELECT n FROM Newsgroup n WHERE n.newsgroup = :newsgroup", Newsgroup.class);
Newsgroup result = (Newsgroup) query.getSingleResult();
newsgroup = (result == null) ? new Newsgroup(folder) : result;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@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 Article)) {
return false;
}
Article other = (Article) 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 "\nmessageNumber\t" + messageNumber;
}
public int getMessageNumber() {
return messageNumber;
}
public void setMessageNumber(int messageNumber) {
this.messageNumber = messageNumber;
}
}
堆栈跟踪：
run:
DEBUG: nntp: newsrc loading /home/thufir/.newsrc
DEBUG: nntp: newsrc load: 5 groups in 39ms
[EL Info]: 2012-08-03 03:26:30.737--ServerSession(13970219)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Info]: 2012-08-03 03:26:31.815--ServerSession(13970219)--file:/home/thufir/NetBeansProjects/USENET/build/classes/_USENETPU login successful
Aug 03, 2012 3:26:32 AM net.bounceme.dur.usenet.driver.FetchBean <init>
INFO: [gwene.com.androidcentral, gwene.com.blogspot.emacsworld, gwene.com.blogspot.googlecode, gwene.com.blogspot.googlereader, gwene.com.economist]
Aug 03, 2012 3:26:32 AM net.bounceme.dur.usenet.driver.FetchBean <init>
INFO: Google helping out newcomers with Nexus 7 getting started video
Aug 03, 2012 3:26:33 AM net.bounceme.dur.usenet.driver.FetchBean main
SEVERE: null
java.lang.IllegalStateException: Query argument newsgroup not found in the list of parameters provided during query execution.
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.processParameters(EJBQueryImpl.java:829)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.executeReadQuery(EJBQueryImpl.java:406)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getSingleResult(EJBQueryImpl.java:773)
at net.bounceme.dur.usenet.model.Article.<init>(Article.java:34)
at net.bounceme.dur.usenet.driver.FetchBean.<init>(FetchBean.java:41)
at net.bounceme.dur.usenet.driver.FetchBean.main(FetchBean.java:21)
BUILD SUCCESSFUL (total time: 13 seconds)
对于新闻组名称，named参数应该是ng，但我似乎无法获得在中查询该字符串的语法字段。如何修复查询？
-------------编辑----------------
新的跟踪：
run:
DEBUG: nntp: newsrc loading /home/thufir/.newsrc
DEBUG: nntp: newsrc load: 5 groups in 30ms
[EL Info]: 2012-08-03 03:57:03.647--ServerSession(33288487)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Info]: 2012-08-03 03:57:04.691--ServerSession(33288487)--file:/home/thufir/NetBeansProjects/USENET/build/classes/_USENETPU login successful
Aug 03, 2012 3:57:05 AM net.bounceme.dur.usenet.driver.FetchBean <init>
INFO: [gwene.com.androidcentral, gwene.com.blogspot.emacsworld, gwene.com.blogspot.googlecode, gwene.com.blogspot.googlereader, gwene.com.economist]
Aug 03, 2012 3:57:05 AM net.bounceme.dur.usenet.driver.FetchBean <init>
INFO: Google helping out newcomers with Nexus 7 getting started video
Aug 03, 2012 3:57:06 AM net.bounceme.dur.usenet.driver.FetchBean main
SEVERE: null
java.lang.IllegalArgumentException: You have attempted to set a parameter value using a name of gwene.com.androidcentral that does not exist in the query string SELECT n FROM Newsgroup n WHERE n.newsgroup = :ng.
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.setParameterInternal(EJBQueryImpl.java:1256)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.setParameter(EJBQueryImpl.java:1138)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.setParameter(EJBQueryImpl.java:81)
at net.bounceme.dur.usenet.model.Article.<init>(Article.java:34)
at net.bounceme.dur.usenet.driver.FetchBean.<init>(FetchBean.java:41)
at net.bounceme.dur.usenet.driver.FetchBean.main(FetchBean.java:21)
BUILD SUCCESSFUL (total time: 17 seconds)
代码段：
String ng = folder.getFullName();
Query query = em.createQuery("SELECT n FROM Newsgroup n WHERE n.newsgroup = :ng", Newsgroup.class);
query.setParameter(ng, ng); //newsgroup object????
Newsgroup result = (Newsgroup) query.getSingleResult();
LOG.info(result.toString());
newsgroup = (result == null) ? new Newsgroup(folder) : result;
我玩了，毫无疑问会得到它，只需要阅读docs和API多一点，但它是足够接近:)
你在引用哪个API？ http://docs.oracle.com/javaee/5/api/javax/persistence/Query.html – Thufir 2012-08-03 11:26:18
对不起，我错过了hibernate的Query接口。它有这样的方法。 – dimas 2012-08-03 11:28:35