Session session = getSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            session.saveOrUpdate(contrat);
            tx.commit();
        } catch (Exception e) {
            if (tx != null) tx.rollback();
            throw e;
        } finally {

        }

java.lang.IllegalStateException: Transaction not active
	at org.hibernate.ejb.TransactionImpl.getRollbackOnly(TransactionImpl.java:132)
	at org.springframework.orm.jpa.JpaTransactionManager$JpaTransactionObject.isRollbackOnly(JpaTransactionManager.java:612)
	at org.springframework.transaction.support.DefaultTransactionStatus.isGlobalRollbackOnly(DefaultTransactionStatus.java:157)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:742)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
	at com.sun.proxy.$Proxy268.getStay(Unknown Source)...
	

    <persistence-unit name="persistenceUnit">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="false" />
            <property name="hibernate.generate_statistics" value="false" />
            <property name="hibernate.default_schema" value="public" />
            <property name="hibernate.cache.use_second_level_cache" value="true" />
            <property name="hibernate.cache.provider_class" value="org.hibernate.cache.EhCacheProvider" />
            <property name="hibernate.cache.use_query_cache" value="true" />
            <property name="current_session_context_class" value="thread"/>
            </properties>
    </persistence-unit>

 <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" >
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>
<bean  id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="persistenceUnitName" value="persistenceUnit" />
    </bean>