EJB - Everything works except persist()

[Julie Lo]

Hello, this is my first application using openEJB and I'm trying to develop a simple Blog.
I have four entities : User, Comment, Post and Categories (a post can have multiple categories)
Here is the code of my Category Entity :

/* Imports */
@Entity
@Table(name="CATEGORIES")
public class Category implements Serializable {
private static final long serialVersionUID = 9136523920135788833L;
@Id
@GeneratedValue
private Long id;
private String name;
@Lob
private String description;
@ManyToMany
@JoinTable(name="POSTS_CATEGORIES",
joinColumns = { @JoinColumn(name="category_fk") },
inverseJoinColumns = { @JoinColumn(name="post_fk") })
private List<Post> posts;
/* Constructors, Getters and Setters */
}

And in my JpaCategoryDao (where I have the @stateless), I have :

/*Imports*/
@Stateless
public class JpaCategoryDao implements CategoryDao {
@PersistenceContext
private EntityManager em;
@Override
public List<Category> getAllCategorie() {
Query query = em.createQuery("SELECT c FROM Category c ORDER BY c.name");
@SuppressWarnings("unchecked")
List<Category> categories = query.getResultList();
return categories;
}
@Override
public Category addCategory(Category category) {
em.persist(category);
return category;
}
@Override
public Category getCategoryById(Long id) {
return em.find(Category.class, id);
}
}

When I try to call the JpaCategoryDao.addCategory(), I have an exception :

exception

javax.ejb.EJBTransactionRolledbackException: Transaction was rolled back, presumably because setRollbackOnly was called during a synchronization
org.apache.openejb.core.ivm.BaseEjbProxyHandler.convertException(BaseEjbProxyHandler.java:341)
org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:287)
$Proxy72.addCategory(Unknown Source)
com.supinfo.sun.supinblog.servlet.AddCategoryServlet.doPost(AddCategoryServlet.java:49)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.supinfo.sun.supinblog.filter.AuthenticateFilter.doFilter(AuthenticateFilter.java:56)

I've been searching about this exception, but I can't find a solution, I don't even understand what I do wrong. Especially because in my Dao where I have em.merge(), it works, I didin't tried the em.delete() but all other functions works (em.find, queries, etc)
So I've been thinking that I probably did something wrong when i declared my entities, or when I create my tables and fields in my database... But I've been searching for hours now, and I can't find what is wrong...

My Entities : (I don't write all my setters and getters)

@Entity
@Table(name="USERS")
public class User implements Serializable{
private static final long serialVersionUID = -7967156157150553165L;
@Id
@GeneratedValue
private Long id;
private String username;
private String password;
private String email;
@Temporal(TemporalType.DATE)
private Date dateOfBirth;
@OneToMany(mappedBy="author")
private List<Post> posts;
@OneToMany(mappedBy="author")
private List<Comment> comments;
}

@Entity
@Table(name="POSTS")
public class Post implements Serializable {
private static final long serialVersionUID = 2824989265126417661L;
@Id
@GeneratedValue
private Long id;
private String title;
@Lob
private String content;
@Temporal(TemporalType.TIMESTAMP)
private Date creationDate;
@Temporal(TemporalType.TIMESTAMP)
private Date lastModificationDate;
@ManyToMany(mappedBy="posts")
private List<Category> categories;
@ManyToOne
@JoinColumn(name="author_fk")
private User author;
@OneToMany(mappedBy="post")
private List<Comment> comments;
}

@Entity
@Table(name="COMMENTS")
public class Comment implements Serializable {
private static final long serialVersionUID = -478361601488617621L;
@Id
@GeneratedValue
private Long id;
private String content;
@Temporal(TemporalType.TIMESTAMP)
private Date creationdate;
@ManyToOne
@JoinColumn(name="author_fk")
private User author;
@ManyToOne
@JoinColumn(name="post_fk")
private Post post;
}

And Finally, this is the structure of my Mysql Database :
CREATE TABLE `CATEGORIES` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) DEFAULT NULL, `description` longtext, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; -- -------------------------------------------------------- CREATE TABLE `COMMENTS` ( `id` int(11) NOT NULL AUTO_INCREMENT, `content` varchar(1000) NOT NULL, `creationDate` datetime NOT NULL, `author_fk` int(11) DEFAULT NULL, `post_fk` int(11) NOT NULL, PRIMARY KEY (`id`), KEY `author_fk` (`author_fk`), KEY `post_fk` (`post_fk`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; -- -------------------------------------------------------- CREATE TABLE `POSTS` ( `id` int(11) NOT NULL AUTO_INCREMENT, `title` varchar(255) NOT NULL, `content` varchar(2000) NOT NULL, `creationDate` datetime NOT NULL, `lastModificationDate` datetime DEFAULT NULL, `author_fk` int(11) NOT NULL, PRIMARY KEY (`id`), KEY `author_fk` (`author_fk`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; -- -------------------------------------------------------- CREATE TABLE `POSTS_CATEGORIES` ( `post_fk` int(11) NOT NULL, `category_fk` int(11) NOT NULL, PRIMARY KEY (`post_fk`,`category_fk`), KEY `post_fk` (`post_fk`), KEY `category_fk` (`category_fk`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; -- -------------------------------------------------------- CREATE TABLE `USERS` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(255) NOT NULL, `password` varchar(255) NOT NULL, `email` varchar(255) NOT NULL, `dateOfBirth` date NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1;

If someone can help me, it would be great... Because I don't see what's wrong...

(And also, I'm sorry for my expression, but I'm french, so...)

Thank You very much !!

[Praful Thakare]

check the exception log before "Transaction was rolled back" log, the rollback will happen only after there is any database exception, can you post your client code that is invoking addCategory ? are you passing unique value for Id? this is general error during trial and error for first time...

[Julie Lo]

It's okay, I solved my problem.
I've been looking into Mysql Queries log, and my problem was that the table OPENJPA_SEQUENCE_TABLE didn't exist, so I had to create it manually and now it works perfectly