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How期間提供的參數列表中沒有找到的查詢參數富做我設置的參數爲下面的查詢的說法：在查詢執行
實體：
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;
}
}
堆棧跟蹤：
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)
對於新聞組名稱，named參數應該是ng，但我似乎無法獲得在中查詢該字符串的語法字段。如何修復查詢？
-------------編輯----------------
新的跟蹤：
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)
代碼段：
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，毫無疑問會得到它，只需要閱讀docs和API多一點，但它是足夠接近:)
你在引用哪個API？ http://docs.oracle.com/javaee/5/api/javax/persistence/Query.html – Thufir 2012-08-03 11:26:18
對不起，我錯過了hibernate的Query接口。它有這樣的方法。 – dimas 2012-08-03 11:28:35