how to update OneToMany

[Thomas Willingham]

I am using hibernate, jpa 2.0, I can persist a OneToMany relationship ok but can't update it (by adding a new element), I have tried many methods and get 1 of two errors each time, "can't insert null into user_id" or "UserRoles is transient persist first". There seems to be no way to do this, are my annotations wrong. It seems it wants me to persist user roles first but if I try it tells me user_id can not be null, but I can't set user id only user object???

    

package mycomany.myproject.database.beans ;

import java.io.Serializable ;
import javax.persistence.Basic ;
import javax.persistence.Column ;
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.SequenceGenerator ;
import javax.persistence.Table ;
import org.apache.commons.lang.builder.ToStringBuilder ;

/**
 *
 */
@ Entity ( )
@ Table ( name = "USER_ROLES" )
public class UserRoles implements Serializable
{
     private static final long serialVersionUID = 1L ;

     @ Id ( )
     @ SequenceGenerator ( name = "UserRolesIdGenerator" , sequenceName = "SEQ_USER_ROLES" )
     @ GeneratedValue ( strategy = GenerationType.SEQUENCE , generator = "UserRolesIdGenerator" )
     @ Column ( name = "ID" , precision = 38 )
     private Long id ;

     @ Basic ( )
     @ Column ( name = "ROLE" , unique = false , nullable = false , length = 100 )
     private String role ;

     @ ManyToOne ( optional = false )
     @ JoinColumn ( name = "user_id" )
     private Users user ;


     public UserRoles ( )
     {
     }


     public Long getId ( )
     {
          return this.id ;
     }


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


     public Users getUser ( )
     {
          return this.user ;
     }


     public void setUser ( Users user )
     {
          this.user = user ;
     }


     public static long getSerialVersionUID ( )
     {
          return UserRoles.serialVersionUID ;
     }


     public String getRole ( )
     {
          return this.role ;
     }


     public void setRole ( String role )
     {
          this.role = role ;
     }


     @ Override
     public String toString ( )
     {
          return new ToStringBuilder ( this ).append ( "id" , this.id ).append ( "role" , this.role ).append ( "user" , this.user ).toString ( ) ;
     }

}

package mycomany.myproject.database.beans ;

import java.io.Serializable ;
import java.util.Set ;
import javax.persistence.Basic ;
import javax.persistence.CascadeType ;
import javax.persistence.Column ;
import javax.persistence.Entity ;
import javax.persistence.FetchType ;
import javax.persistence.GeneratedValue ;
import javax.persistence.GenerationType ;
import javax.persistence.Id ;
import javax.persistence.OneToMany ;
import javax.persistence.SequenceGenerator ;
import javax.persistence.Table ;
import org.apache.commons.lang.builder.ToStringBuilder ;

@ Entity ( )
@ Table ( name = "USERS" )
public class Users implements Serializable
{
     private static final long serialVersionUID = 1L ;

     @ Id ( )
     @ SequenceGenerator ( name = "UsersIdGenerator" , sequenceName = "SEQ_USERS" )
     @ GeneratedValue ( strategy = GenerationType.SEQUENCE , generator = "UsersIdGenerator" )
     @ Column ( name = "ID" , precision = 38 )
     private Long id ;

     @ Basic ( )
     @ Column ( name = "EMAIL_ADDRESS" , unique = true , nullable = false , length = 500 )
     private String emailAddress ;

     @ Basic ( )
     @ Column ( name = "PASSWORD" , unique = false , nullable = false , length = 500 )
     private String password ; // the hash'd password goes in here

     @ Basic ( )
     @ Column ( name = "DATE_CREATED" , unique = false , nullable = false , length = 500 )
     private java.sql.Timestamp date_created ;

     @ Basic ( )
     @ Column ( name = "DATE_PWD_CHANGED" , unique = false , nullable = false , length = 500 )
     private java.sql.Timestamp date_pwd_changed ;

     @ OneToMany ( mappedBy = "user" , fetch = FetchType.EAGER , cascade = {CascadeType.REFRESH,CascadeType.REMOVE} )
     private Set < UserRoles > userRoles ; // how do we update this ?????


     public Users ( )
     {
     }


     public Long getId ( )
     {
          return this.id ;
     }


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


     public String getEmailAddress ( )
     {
          return this.emailAddress ;
     }


     public void setEmailAddress ( String emailAddress )
     {
          this.emailAddress = emailAddress ;
     }


     public String getPassword ( )
     {
          return this.password ;
     }


     public void setPassword ( String password )
     {
          this.password = password ;
     }


     public java.sql.Timestamp getDate_created ( )
     {
          return this.date_created ;
     }


     public void setDate_created ( java.sql.Timestamp date_created )
     {
          this.date_created = date_created ;
     }


     public java.sql.Timestamp getDate_pwd_changed ( )
     {
          return this.date_pwd_changed ;
     }


     public void setDate_pwd_changed ( java.sql.Timestamp date_pwd_changed )
     {
          this.date_pwd_changed = date_pwd_changed ;
     }


     public Set < UserRoles > getUserRoles ( )
     {
          return this.userRoles ;
     }


     public void setUserRoles ( Set < UserRoles > userRoles )
     {
          this.userRoles = userRoles ;
     }


     public static long getSerialVersionUID ( )
     {
          return Users.serialVersionUID ;
     }


     @ Override
     public String toString ( )
     {
          return new ToStringBuilder ( this ).append ( "id" , this.id ).append ( "emailAddress" , this.emailAddress ).append ( "password" , this.password ).append ( "date_created" , this.date_created ).append ( "date_pwd_changed" , this.date_pwd_changed ).append ( "userRoles" , this.userRoles ).toString ( ) ;
     }

} 

   
      //part of servlet code to add user role
     {
          String id = NullChecker.checkForNull ( request.getParameter ( "id" ) ); // the user id
          String role = NullChecker.checkForNull ( request.getParameter ( "role" ) ) ;
          String next_page = "/ManageUsersServlet.do" ;
          AddRoleServlet.LOG.debug("id = "+id);
          AddRoleServlet.LOG.debug("role = "+role);
          EntityManager em = null;
          Users user = null;
          boolean rolePresent=false;
          try
          {
               em = EntityUtils.getEntityManager();
               List<Users> users = UsersDao.getById ( Long.valueOf ( id ) , em, false); //pass in em, if false wont close entity manager
               if (users!=null)
               {
                    //~~~~~~~~~~~~~~~ LOOK FOR ROLE
                    for ( UserRoles roleA : users.get ( 0 ).getUserRoles ( ) )
                    {
                         if ( NullChecker.checkForNull ( roleA.getRole ( ) ).equals ( role ) )
                         {
                              rolePresent=true;
                         }
                    }
                    //~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~
                    if (!rolePresent)
                    {
                         UserRoles userRole = new UserRoles();
                         userRole.setRole ( role );
                         userRole.setUser ( user );
                         //em.persist ( userRole ); // with and without this? no luck
                         Users myUser = users.get(0);
                         if ( myUser.getUserRoles ( ) == null )
                         {
                              myUser.setUserRoles ( new HashSet<UserRoles>( ));
                         }
                         myUser.getUserRoles ( ).add ( userRole );
                         myUser = em.merge ( myUser );
                    }
                    //~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~
               }
               em.getTransaction ( ).commit ( );
               request.setAttribute ( "message" , Constants.SUCCESS_MESSAGE.toString ( ) ) ;
          }
          catch ( Exception e )
          {
               em.getTransaction ( ).rollback ( );
               AddRoleServlet.LOG.error(ExceptionTools.getStackTrace(e));
          }
          finally
          {
               EntityUtils.closeEntityManager ( em );
          } 

[Thomas Willingham]

got it working with this

    
				if ( ! rolePresent )
				{
					UserRoles userRole = new UserRoles ( ) ;
					userRole.setRole ( role ) ;
					userRole.setUser ( user ) ;
					//em.persist ( userRole );
					Users myUser = users.get ( 0 ) ;
					if ( myUser.getUserRoles ( ) == null )
					{
						myUser.setUserRoles ( new HashSet < UserRoles > ( ) ) ;
					}
					myUser.getUserRoles ( ).add ( userRole ) ;
					userRole.setUser ( myUser ) ;
					myUser = em.merge ( myUser ) ;
				}