Upgrading Spring 3.x and Hibernate 3.x to Spring Platform 1.0.1 (Spring + hibernate 4.x)

Brian Du PreezAugust 20th, 2014Last Updated: August 20th, 2014

1 50 2 minutes read

I recent volunteered to upgrade our newest project to the latest version of Spring Platform. What Spring Platform gives you is dependency & plugin management across the whole Spring framework’s set of libraries.

Since we had fallen behind a little the upgrade did raise some funnies. Here are the things I ran into:

Maven:

Our pom files were still referencing:
hibernate.jar
ehcache.jar

These artefacts don’t exit on the latest version, so replaced those with hibernate-core.jar and ehcache-core.jar.

We also still use the hibernate tools + maven run plugin to reverse engineer our db object. This I needed to update to a release candidate:

<hibernate-tools .version="">4.3.1.CR1</hibernate-tools>

Hibernate:

The code: “Hibernate.createBlob”… no longer exists

replaced with:

private Blob createBlob(final byte[] bytes) {
return NonContextualLobCreator.INSTANCE.wrap(NonContextualLobCreator.INSTANCE.createBlob(bytes));
}

On the HibernateTemplate return types are now List; not element…So needed to add casts for the lists being returned.

import org.hibernate.classic.Session;

replaced with:

import org.hibernate.Session;

Reverse engineer works a little differently…
Assigns Long to numeric…
Added:

<type-mapping>
 <sql-type jdbc-type="NUMERIC" precision="4" hibernate-type="java.lang.Integer" />
 <sql-type jdbc-type="NUMERIC" precision="6" hibernate-type="java.lang.Integer" />
 <sql-type jdbc-type="NUMERIC" precision="8" hibernate-type="java.lang.Integer" />
 <sql-type jdbc-type="NUMERIC" precision="10" hibernate-type="java.lang.Long" />
 <sql-type jdbc-type="DECIMAL" precision='4' scale='0' hibernate-type="java.lang.Integer" not-null="true"/>
 <sql-type jdbc-type="DECIMAL" precision='6' scale='0' hibernate-type="java.lang.Integer" not-null="true"/>
 <sql-type jdbc-type="DATE" hibernate-type="java.util.Date"/>
</type-mapping>

Possible Errors:

Caused by: org.hibernate.service.UnknownUnwrapTypeException: Cannot unwrap to requested type [javax.sql.DataSource]

Add a dependency for c3p0:

<dependency>
 <groupid>org.hibernate</groupId>
 <artifactid>hibernate-c3p0</artifactId>
 <version>${hibernate.version}</version>
</dependency>

And configure the settings in the cfg.xml for it:

<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">20</property>
<property name="hibernate.c3p0.timeout">300</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>

Caused by: java.lang.ClassNotFoundException: org.hibernate.engine.FilterDefinition

Probably still using a reference to hibernate3 factory / bean somewhere, change to hibernate4:

org.springframework.orm.hibernate3.LocalSessionFactoryBean
org.springframework.orm.hibernate3.HibernateTransactionManager

Caused by: java.lang.ClassNotFoundException: Could not load requested class : org.hibernate.hql.classic.ClassicQueryTranslatorFactory There is minor change in new APIs, so this can be resolved by replacing property value with:

org.hibernate.hql.internal.classic.ClassicQueryTranslatorFactory.

Spring:

Amazingly some of our application context files still referenced the Spring DTD … replaced with XSD:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">

In Spring configs added for c3p0:

<prop key="hibernate.c3p0.min_size">5</prop>
<prop key="hibernate.c3p0.max_size">20</prop>
<prop key="hibernate.c3p0.timeout">300</prop>
<prop key="hibernate.c3p0.max_statements">50</prop>
<prop key="hibernate.c3p0.idle_test_period">3000</prop>

Spring removed the “local”=: so needed to just change that to “ref”=

Spring HibernateDaoSupport no longer has: “releaseSession(session);”, which is a good thing so was forced to update the code to work within a transaction.

Possible Errors:

getFlushMode is not valid without active transaction; nested exception is org.hibernate.HibernateException: getFlushMode is not valid without active transaction

Removed from hibernate properties:

<prop key="hibernate.current_session_context_class">thread</prop>

Supply a custom strategy for the scoping of the “current”Session. See Section 2.5, “Contextual sessions” for more information about the built-in strategies

org.springframework.dao.InvalidDataAccessApiUsageException: Write operations are not allowed in read-only mode (FlushMode.MANUAL): Turn your Session into FlushMode.COMMIT/AUTO or remove ‘readOnly’ marker from transaction definition.

Another option is :

<bean id ="productHibernateTemplate" class="org.springframework.orm.hibernate4.HibernateTemplate">
<property name="sessionFactory" ref="productSessionFactory"/>
<property name="checkWriteOperations" value="false"/>
</bean>

java.lang.NoClassDefFoundError: javax/servlet/SessionCookieConfig

Servlet version update:

<dependency>
 <groupid>javax.servlet</groupId>
 <artifactid>servlet-api</artifactId>
 <version>3.0.1</version>
</dependency>

Then deploying on weblogic javassist: $$_javassist_ cannot be cast to javassist.util.proxy.Proxy

The issue here was that there were different versions of javassist being brought into the ear. I all references removed from all our poms, so that the correct version gets pulled in from from Spring/Hibernate…

and then configured weblogic to prefer our version:

<?xml version="1.0" encoding="UTF-8"?>
<weblogic-application>
 <application-param>
  <param-name>webapp.encoding.default</param-name>
  <param-value>UTF-8</param-value>
 </application-param>
 
<prefer-application-packages>
<package-name>javax.jws.*</package-name>
<package-name>org.apache.xerces.*</package-name>
<package-name>org.apache.xalan.*</package-name>
<package-name>org.apache.commons.net.*</package-name>
<package-name>org.joda.*</package-name>
<package-name>javassist.*</package-name>
</prefer-application-packages>
</weblogic-application>

Reference:

Upgrading Spring 3.x and Hibernate 3.x to Spring Platform 1.0.1 (Spring + hibernate 4.x) from our JCG partner Brian Du Preez at the Zen in the art of IT blog.