java hibernate tomcat configuration - Session will not be opened - java

I am trying to configure hibernate and tomcat, so that tomcat will manage the database conections, but I am getting some errors.
Could you help? Here is my code:
Here is the HibernateUtil
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
return new AnnotationConfiguration().configure().buildSessionFactory();
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static void shutdown() {
// Close caches and connection pools
getSessionFactory().close();
}
}
HibernateListener:
public class HibernateListener implements ServletContextListener {
/* public void contextInitialized(ServletContextEvent event) {
HibernateUtil.getSessionFactory(); // Just call the static initializer
// of that class
}
public void contextDestroyed(ServletContextEvent event) {
HibernateUtil.getSessionFactory().close(); // Free all resources
}
}*/
#Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("\n\tInside contextInitialized()\n")
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
}
#Override
public void contextDestroyed(ServletContextEvent arg0) {
HibernateUtil.shutdown();
}
}
I have also made an entry in web.xml
<listener>
<listener-class>hibernate.HibernateListener</listener-class>
</listener>
I have created a jsp file and try to run a piece of code, which is:
public Employee getEmployeeByLogin(String login){
Employee p= null;
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
Query query = session.createQuery("from employee p where p.login = '" + login +"'");
p = (Employee) query.uniqueResult();
return p;
}
The error I am getting is:
org.apache.jasper.JasperException: org.hibernate.HibernateException: createQuery is not valid without active transaction
I tried to do it similar way as described in https://community.jboss.org/wiki/UsingHibernateWithTomcat# but without success....
So once again. Please help.

Related

Hibernate Junit H2 In memory database test case changing fields in the development db

I have developed a project using Hibernate. I am trying to test it using Junit with H2 in memory db but the test case is creating fields in the db that I am using it for development.
Here is my code :
UserDAO.java
public interface UserDAO {
public void addUser(String username, String password);
public List<String> getUsers();
}
UserDAOImpl.java
public class UserDAOImpl implements UserDAO {
public static final Logger LOG = LoggerFactory.getLogger(UserDAOImpl.class);
private static Session session;
private static void beginSession() {
session = DbUtils.getSessionFactory().openSession();
session.beginTransaction();
}
#Override
public void addUser(String username, String password) {
String encryptedPassword = Utils.encrypt(password);
User user = new User(username, encryptedPassword);
beginSession();
try {
session.save(user);
System.out.println(user.getPassword());
session.getTransaction().commit();
} catch (SQLGrammarException e) {
session.getTransaction().rollback();
LOG.error("Cannot save user", e);
} finally {
session.close();
}
}
#Override
public List<String> getUsers() {
beginSession();
List<String> results = new ArrayList<String>();
String hql = "select username from User";
Query query = null;
try {
query = session.createQuery(hql);
results = query.list();
} catch (HibernateException e) {
LOG.error("Cannot execute query", e);
}
return results;
}
}
Files for test cases
SessionFactoryRule.java
public class SessionFactoryRule implements MethodRule {
private SessionFactory sessionFactory;
private Transaction transaction;
private Session session;
#Override
public Statement apply(final Statement statement, FrameworkMethod method, Object test) {
return new Statement() {
#Override
public void evaluate() throws Throwable {
sessionFactory = createSessionFactory();
createSession();
beginTransaction();
try {
statement.evaluate();
} finally {
shutdown();
}
}
};
}
private void shutdown() {
try {
try {
try {
transaction.rollback();
} catch (Exception ex) {
ex.printStackTrace();
}
session.close();
} catch (Exception ex) {
ex.printStackTrace();
}
sessionFactory.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
private SessionFactory createSessionFactory() {
Configuration configuration = new Configuration().configure();
configuration.addAnnotatedClass(User.class)
.addAnnotatedClass(Message.class);
configuration.setProperty("hibernate.dialect",
"org.hibernate.dialect.H2Dialect");
configuration.setProperty("hibernate.connection.driver_class",
"org.h2.Driver");
configuration.setProperty("hibernate.connection.url", "jdbc:h2:./data/db");
configuration.setProperty("hibernate.hbm2ddl.auto", "create");
SessionFactory sessionFactory = configuration.buildSessionFactory();
return sessionFactory;
}
public Session createSession() {
session = sessionFactory.openSession();
return session;
}
public void commit() {
transaction.commit();
}
public void beginTransaction() {
transaction = session.beginTransaction();
}
public Session getSession() {
return session;
}`
Here is my test case
UserDAOTest.java
public class UserDAOTest {
#Rule
public final SessionFactoryRule sf = new SessionFactoryRule();
#Test
public void testAddUser() {
Session session = sf.getSession();
UserDAOImpl userDAOImpl = new UserDAOImpl();
String username = "stackoverflow";
String password = "testing";
userDAOImpl.addUser(username, password);
}
}
This test case is updating the fields username and password in the db that I am using while development. How can I stop it and use h2 in-memory db for testing.
You have session = DbUtils.getSessionFactory().openSession() in the UserDAOImpl. This is the reason of using a development database. Your SessionFactoryRule is not used at all.
So what you can to do.
The best choice is use to Spring for Hibernate configuration and unit testing.
Other option is to set sessionFactory to the UserDAOImpl using constructor.
Also, using static here is a really very very bad idea
private static Session session;

Shorter version of Hibernate query

I have hibernate query, for example get user by id:
public User findById(int id){
SessionFactory sf = HibernateUtil.getSessionFactory();
Session session = sf.openSession();
Transaction tx = null;
User user = null;
try{
tx = session.beginTransaction();
user = (User) session.get(User.class, id);
session.getTransaction().commit();
} catch(HibernateException e){
if(null != tx) tx.rollback();
System.out.println("HibernateException, transaction will be rollbacked");
} catch(Exception e){
e.printStackTrace();
}
finally {
session.close();
}
return user;
}
It's ok for one query, but i need dublicate all of this code to every query.
I need just on single code:
user = (User) session.get(User.class, id);
Is it possible to put other code to another class, method or something else?
Updated
HibernateUtil:
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
return new AnnotationConfiguration().configure()
.buildSessionFactory();
} catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
It is a good practice to keep one Hibernate utility class which will have a static method to provide us the hibernate session. Moreover you can reuse the hibernate session by preventing making a new session on each query by using some simple logic.

How to retrieve sessionFactory from Hibernate 4.3.4.Final?

Previously I was using the following code to configure the sessionFactory, but after upgrading the version of my hibernate from 4.2.1.Final to 4.3.4.Final, I can not retrieve sessionFactory using the following code as ServiceRegistryBuilder() is deprecated.
I used this link to create it but the provided function is not returning any thing therefore it runs into pre-compile error.
private static SessionFactory configureSessionFactory() {
try {
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
return sessionFactory;
} catch (HibernateException e) {
System.out.append("** Exception in SessionFactory **");
e.printStackTrace();
}
return sessionFactory;
}
static {
try {
sessionFactory = configureSessionFactory();
} catch (Exception e) {
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
private HibernateUtil() {
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static Session getSession() throws HibernateException {
Session session = threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession() : null;
threadLocal.set(session);
}
return session;
}
public static void rebuildSessionFactory() {
try {
sessionFactory = configureSessionFactory();
} catch (Exception e) {
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
public static void closeSession() throws HibernateException {
Session session = (Session) threadLocal.get();
threadLocal.set(null);
if (session != null) {
if (session.isOpen()) {
session.close();
}
}
}
In 4.3, you should use the StandardServiceRegistryBuilder instead.
import org.hibernate.boot.registry.StandardServiceRegistryBuilder
StandardServiceRegistryBuilder was added as a new parent of ServiceRegistryBuilder. The rest of the code should be the same. The only place that I have found this documented "clearly" is in the 4.3 JavaDocs for ServiceRegistryBuilder.
One thing that I did not notice was that they changed the ServiceRegistryBuilder.buildServiceRegistry() method to just StandardServiceRegistryBuilder.build(). Therefore, it will require you to change that part of your building process:
new ServiceRegistryBuilder()
.applySettings(configuration.getProperties())
.buildServiceRegistry();
Becomes:
new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties())
.build();
I tested this one and it works on Hibernate 4.3.6
public class HUtil{
private static SessionFactory sessionFactory;
private static ServiceRegistry serviceRegistry;
public static SessionFactory createSessionFactory() {
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new StandardServiceRegistryBuilder().
applySettings(configuration.getProperties()).build();
sessionFactory = configuration.configure(). buildSessionFactory(serviceRegistry);
return sessionFactory;
}
public static SessionFactory getSessionFactory() {
return createSessionFactory();
} }
Yes, they have deprecated the previous ServiceRegistryBuilder(), here is how you can do it with Hibernate 4.3.4
public void testConnection() throws Exception {
logger.info("Trying to Connect With a DataBase.");
Configuration configuration = new Configuration();
configuration.configure("Your.cfg.xml");
ServiceRegistryBuilder serviceRegistryBuilder = new ServiceRegistryBuilder().applySettings(configuration
.getProperties());
SessionFactory sessionFactory = configuration
.buildSessionFactory(serviceRegistryBuilder.buildServiceRegistry());
Session session = sessionFactory.openSession();
logger.info("Database connection created successfuly.");
}
Source: Create session factory in Hibernate 4

HibernateSessionFactory class doesn't change data from database

In our application we have an HibernateSessionFactory class, that is opening and closing connections. Everything is okay, but when we are updating data in the database, it doesn't change in our application. Unfortunately, we see old data from the database. How can I fix this?
public class HibernateSessionFactory {
private static final ThreadLocal threadLocal = new ThreadLocal();
private static org.hibernate.SessionFactory sessionFactory;
private static Configuration configuration = new Configuration();
private static ServiceRegistry serviceRegistry;
private static final Logger log = Logger.getLogger(
HibernateSessionFactory.class);
static {
try {
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder()
.applySettings(configuration.getProperties())
.buildServiceRegistry();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
} catch (Exception e) {
log.error("Error Creating SessionFactory", e);
}
}
private HibernateSessionFactory() {}
public static Session getSession() throws HibernateException {
Session session = (Session) threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ?
sessionFactory.openSession() : null;
threadLocal.set(session);
}
return session;
}
public static void rebuildSessionFactory() {
try {
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder()
.applySettings(configuration.getProperties())
.buildServiceRegistry();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
} catch (Exception e) {
log.error("Error Creating SessionFactory", e);
}
}
public static void closeSession() throws HibernateException {
Session session = (Session) threadLocal.get();
threadLocal.set(null);
if (session != null) {
session.flush();
session.close();
}
}
public static org.hibernate.SessionFactory getSessionFactory() {
return sessionFactory;
}
public static Configuration getConfiguration() {
return configuration;
}
}
.
#SuppressWarnings("unchecked")
public List<Tauthor> getAuthors() throws HibernateException {
log.debug("getting all authors");
Query queryObject = null;
List<Tauthor> authors = null;
Session session = HibernateSessionFactory.getSession();
try {
String queryString = "from Tauthor";
queryObject = session.createQuery(queryString);
authors = queryObject.list();
} catch (HibernateException e) {
log.error("get all authors failed", e);
throw e;
} finally {
HibernateSessionFactory.closeSession();
}
return authors;
}
You haven't shared your code where you write data to the database. Without that, I can think of only a few reasons as to why your data output is old instead of new data:
Your transactions are not being committed.
Hibernate hasn't written to the database at the time of data queried by you.
Hibernate's cache hasn't been updated, which results in query returning old data.
You should verify that data has been written to the Database with a db developer tool and try disabling all hibernate caching to see if the result changes.

Hibernate not closing connection

I am using Hibernate + jersey Rest And Mysql as backend for database. In Hibernate used cp3 pool for connection but after some time it creates so many idle connections and gets stuck. my configurations are :
package com.appname.hibernate.util;
import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static SessionFactory sessionFactory;
static {
try {
Configuration configuration = new Configuration().configure();
sessionFactory = configuration.buildSessionFactory();
} catch (HibernateException he) {
System.err.println("Error creating Session: " + he);
he.printStackTrace();
throw new ExceptionInInitializerError(he);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
////////////////////// INSIDE DAO ///////////////////////////
private Session getSession() {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Session session;
try {
session = sessionFactory.getCurrentSession();
} catch (org.hibernate.HibernateException he) {
session = sessionFactory.openSession();
}
return session;
}
public Users regsiterUser(Users users) throws Exception {
Session session = null;
try {
session = getSession();
Transaction transaction = session.beginTransaction();
session.saveOrUpdate(users);
transaction.commit();
return users;
//Using context session that is why I am not closing session
} catch (Exception e) { throw e; }
}
I am calling this DAO function form my controller where I am making transaction and session inside DAO layer. Please help me I am trying to solve this but not getting any solution please have a look what is wrong with the above configuration and code ......
Thanks in advance.....
I think this session = sessionFactory.openSession(); should be closed manually after use because it is not managed by an orchestrator that release resource after use.

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