EntityManager and Conversation contex
I read both books Seam Contextual components and JBoss® Seam: Simplicity and Power Beyond Java? EE from Safari but I can't seem to find the answer.
I was under impression that persistence context is the same as hiberante session and that if @PersistenceContext(type = EXTENDED) that it would last during conversation, and that it would be shared between EntityManagers from two different action beans if they are in the same conversation.
I hope sample code would explain better my question:
I made a little example.
first there are two entity beans directory and file
directory has a set of files
Directory:
package orka.test;
import java.util.LinkedHashSet;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import org.jboss.seam.annotations.Name;
@Entity
@Name("directory")
@Table(name="directory")
public class Directory {
@Id
@GeneratedValue(strategy=GenerationType.TABLE)
private long sifra;
private String name;
@OneToMany(cascade={CascadeType.ALL},mappedBy="directory")
private Set<File>files= new LinkedHashSet<File>();
public Set<File> getFiles() {
return files;
}
public void setFiles(Set<File> files) {
this.files = files;
}
public long getSifra() {
return sifra;
}
public void setSifra(long sifra) {
this.sifra = sifra;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
File:
package orka.test;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import org.hibernate.validator.NotNull;
import org.jboss.seam.annotations.Name;
@Entity
@Name("file")
@Table(name="file")
public class File {
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
private long sifra;
@NotNull
private String name;
@ManyToOne
@JoinColumn(name="directory")
private Directory directory;
//geters seters
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public long getSifra() {
return sifra;
}
public void setSifra(long sifra) {
this.sifra = sifra;
}
public Directory getDirectory() {
return directory;
}
public void setDirectory(Directory directory) {
this.directory = directory;
}
}
Then two action beans: DirectoryActionBean and FileActionBean
DirectoryActionBean:
package orka.test;
import static javax.persistence.PersistenceContextType.EXTENDED;
import javax.ejb.Remove;
import javax.ejb.Stateful;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.jboss.seam.annotations.Create;
import org.jboss.seam.annotations.Destroy;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Out;
import org.jboss.seam.log.Log;
@Stateful
@Name("directoryAction")
public class DirectoryActionBean implements DirectoryAction {
@PersistenceContext(type = EXTENDED)
private EntityManager manager;
@SuppressWarnings("unused")
@org.jboss.seam.annotations.Logger
private Log log;
@In(required = false)
@Out
Directory directory;
public void saveDir() {
manager.persist(directory);
}
public String goFiles() {
return "files";
}
@Remove
@Destroy
public void destroy() {
}
@Create
public void create() {
directory = new Directory();
directory.setName("dirOne");
manager.persist(directory);
}
}
FileActionBean:
package orka.test;
import static javax.persistence.PersistenceContextType.EXTENDED;
import javax.ejb.Remove;
import javax.ejb.Stateful;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.jboss.seam.annotations.Destroy;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Out;
import org.jboss.seam.log.Log;
@Stateful
@Name("fileAction")
public class FileActionBean implements FileAction {
@PersistenceContext(type = EXTENDED)
private EntityManager manager;
@SuppressWarnings("unused")
@org.jboss.seam.annotations.Logger
private Log log;
@In
@Out
Directory directory;
public void newFile(){
File file= new File();
file.setName("fileOne");
file.setDirectory(directory);
directory.getFiles().add(file);
manager.persist(file);
}
public String backToDir(){
return "dir";
}
@Remove
@Destroy
public void destroy() {
}
}
and at last part of pages.xml:
<page view-id="/directory.jsp"> <begin-conversation join="true"/> <navigation > <rule if-outcome="files"> <redirect view-id="/file.jsp"> </redirect> </rule> </navigation> </page> <page view-id="/file.jsp"> <navigation > <rule if-outcome="dir"> <redirect view-id="/directory.jsp"> </redirect> </rule> </navigation> </page>
I will not bother you with jsp pages let just say that directory.jsp references only directory entity bean a makes calls only to directoryActionBean it is the same pattern for file.jsp
Now to explain what I do: At first
I create one directory from directoryAction than go to file.jsp and create file, add him in directory and persist file.
After that I return focus to directory.jsp and invoke method save.
Then I get exception
org.hibernate.PersistentObjectException: detached entity passed to persist: orka.test.File
javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist: orka.test.File at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:647) at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:218) at org.jboss.ejb3.entity.ExtendedEntityManager.persist(ExtendedEntityManager.java:104) at orka.test.DirectoryActionBean.saveDir(DirectoryActionBean.java:33) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at org.jboss.seam.intercept.EJBInvocationContext.proceed(EJBInvocationContext.java:37) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:55) at org.jboss.seam.interceptors.BijectionInterceptor.bijectNonreentrantComponent(BijectionInterceptor.java:79) at org.jboss.seam.interceptors.BijectionInterceptor.bijectComponent(BijectionInterceptor.java:58) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.seam.util.Reflections.invoke(Reflections.java:18) at org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64) at org.jboss.seam.interceptors.ManagedEntityIdentityInterceptor.aroundInvoke(ManagedEntityIdentityInterceptor.java:36) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.seam.util.Reflections.invoke(Reflections.java:18) at org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64) at org.jboss.seam.interceptors.OutcomeInterceptor.interceptOutcome(OutcomeInterceptor.java:21) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.seam.util.Reflections.invoke(Reflections.java:18) at org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64) at org.jboss.seam.interceptors.ConversationInterceptor.endOrBeginLongRunningConversation(ConversationInterceptor.java:52) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.seam.util.Reflections.invoke(Reflections.java:18) at org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64) at org.jboss.seam.interceptors.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:27) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.seam.util.Reflections.invoke(Reflections.java:18) at org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64) at org.jboss.seam.intercept.RootInterceptor.createSeamInvocationContext(RootInterceptor.java:144) at org.jboss.seam.intercept.RootInterceptor.invokeInContexts(RootInterceptor.java:129) at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:102) at org.jboss.seam.intercept.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:50) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:118) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.ExtendedPersistenceContextPropagationInterceptor.invoke(ExtendedPersistenceContextPropagationInterceptor.java:71) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79) ... 68 more
It works fine if I merge directory before persist, but I don't understand why do I have to merge some thing if it was changed in side long running session and it should not have been detached. Maybe I am doing some thing wrong or I did not understand concept of conversation very well.
Like I sad at the beginning I understood that one session could span many request/response cycles and many action beans as long as they are in one conversation and session is long-running.
To merge some thing before persist in some situations is not a big deal, but I would really like to fully understand concepts behind seam
Please Explain!!!
Thanks in advance Kruno.
