Hibernate4报错createQuery is not valid without active transaction

就是在这里查询就出错了
@Override

public User get(int id) {
    Session session = sessionFactory.getCurrentSession();
    String sql = "from User where id = :id";
    Query query = session.**createQuery(sql)**;
    query.setParameter("id", id);
    query.setMaxResults(1);
    User user = (User)query.uniqueResult();
    return user;
}

spring的配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
                        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd  
                        http://www.springframework.org/schema/context  
                        http://www.springframework.org/schema/context/spring-context-3.1.xsd
                        http://www.springframework.org/schema/tx 
                        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
                        http://www.springframework.org/schema/mvc  
                        http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
    <!-- 自动扫描 -->
    <context:component-scan base-package="com.baofan.mavenmvc" />
    <!-- 引入配置文件 -->
    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties" />
    </bean>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close">
        <property name="driverClassName" value="${driver}" />
        <property name="url" value="${url}" />
        <property name="username" value="${username}" />
        <property name="password" value="${password}" />
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="${initialSize}"></property>
        <!-- 连接池最大数量 -->
        <property name="maxActive" value="${maxActive}"></property>
        <!-- 连接池最大空闲 -->
        <property name="maxIdle" value="${maxIdle}"></property>
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="${minIdle}"></property>
        <!-- 获取连接最大等待时间 -->
        <property name="maxWait" value="${maxWait}"></property>
    </bean>
    
    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource">
            <ref bean="dataSource" />
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">
                    org.hibernate.dialect.MySQLDialect
                </prop>
                <prop key="hibernate.hbm2ddl.auto">none</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.query.substitutions">true 1, false 0</prop>
                <prop key="hibernate.default_batch_fetch_size">16</prop>
                <prop key="hibernate.max_fetch_depth">2</prop>
                <prop key="hibernate.generate_statistics">true</prop>
                <prop key="hibernate.bytecode.use_reflection_optimizer">true</prop>
                <prop key="hibernate.current_session_context_class">thread</prop>
            </props>
        </property>
        <!-- 自动扫描实体对象 com.baofan.shtest.model的包结构中存放实体类 -->
        <property name="packagesToScan" value="com.baofan.mavenmvc.entity" />
    </bean>

    <bean id="transactionManager"
        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <!-- 配置事务异常封装 -->
    <bean id="persistenceExceptionTranslationPostProcessor"
        class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
    <tx:annotation-driven transaction-manager="transactionManager" />
</beans>

---

原因是你的业务方法没有加上事务，看你用的是spring，可以使用spring的声明式事务。
给你段配置，你可以简单参考下

<tx:advice transaction-manager="transactionManager" id="txAdvice">
    <tx:attributes>
        <tx:method name="get*" read-only="true"/>
        <tx:method name="find*" read-only="true"/>
        <tx:method name="count*" read-only="true"/>
        <tx:method name="*" />
    </tx:attributes>
</tx:advice>

<aop:config>
    <aop:pointcut expression="execution(* xx.xx.service.*.*(..))" id="txPointCut"/>
    <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
</aop:config>