spring Hibernate-无法为当前线程获取事务同步会话

Question

我用spring+hibernate创建了一个应用程序，但总是得到这个错误。这是我使用hibernate的第一个应用程序，我读了一些指南，但我不能解决这个问题。我哪里做错了？

这是我的应用程序的代码

ott 05, 2014 4:03:06 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
Informazioni: Refreshing   org.springframework.context.support.ClassPathXmlApplicationContext@1eab16b: startup date  [Sun Oct 05 16:03:06 CEST 2014]; root of context hierarchy
ott 05, 2014 4:03:06 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
Informazioni: Loading XML bean definitions from class path resource [springConfig.xml]
ott 05, 2014 4:03:08 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.5.Final}
ott 05, 2014 4:03:08 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.6.Final}
ott 05, 2014 4:03:08 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
ott 05, 2014 4:03:08 PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
ott 05, 2014 4:03:09 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQL5Dialect
ott 05, 2014 4:03:09 PM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
ott 05, 2014 4:03:09 PM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
Exception in thread "main" org.hibernate.HibernateException: Could not obtain transaction-synchronized Session for current thread
at org.springframework.orm.hibernate4.SpringSessionContext.currentSession(SpringSessionContext.java:134)
at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:1014)
at coreservlets.StudentDAOImpl.create(StudentDAOImpl.java:19)
at coreservlets.MainApp.main(MainApp.java:14)

student.java

package coreservlets;

public class Student {

    private Integer id;
    private String name;
    private Integer age;

    public Integer getId(){return id;}//getId

    public void setId(Integer id){this.id=id;}//setId

    public String getName(){return name;}//getName

    public void setName(String name){this.name=name;}//setName

    public Integer getAge(){return age;}//getAge

    public void setAge(Integer age){this.age=age;}//setAge

}//Student

StudentDAO.java

package coreservlets;

import org.hibernate.SessionFactory;

public interface StudentDAO {

    public void setSessionFactory(SessionFactory sessionFactory);

    public void create(String name,Integer age);

}//StudentDAO

StudentDAOImpl.java

package coreservlets;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository
public class StudentDAOImpl implements StudentDAO {

    private SessionFactory sessionFactory;

    @Autowired
    public void setSessionFactory(SessionFactory sessionFactory){
        this.sessionFactory=sessionFactory;
    }//setSessionFactory

    public void create(String name,Integer age){
        Session session=sessionFactory.getCurrentSession();
        Student student=new Student();
        student.setName(name);
        student.setAge(age);
        session.save(student);
    }//create

}//StudentDAOImpl

MainApp.java

package coreservlets;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {

    public static void main(String[] args) {

        ApplicationContext context=new ClassPathXmlApplicationContext("springConfig.xml");

        StudentDAOImpl student=(StudentDAOImpl) context.getBean("studentDAOImpl");

        student.create("Alessandro", new Integer(33));


    }//main

}//MainApp

SpringConfig.xml

<?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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">

<context:annotation-config/>

<context:component-scan base-package="coreservlets"/>

<bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
  <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
  <property name="url" value="jdbc:mysql://localhost:3306/spring_hibernate"/>
  <property name="username" value="root"/>
  <property name="password" value="password"/>
  <property name="initialSize" value="5"/>
  <property name="maxTotal" value="10"/>
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="hibernateProperties">
    <value>
            hibernate.dialect=org.hibernate.dialect.MySQLDialect
    </value>
</property>

</bean>

</beans>

SQL

create table student
(
id integer not null auto_increment,
name varchar(20) not null,
age integer not null,
primary key(id)
);

Answer 1

我也遇到过同样的问题，但在一个不属于服务层的类中。在我的例子中，事务管理器只是通过getBean()方法从上下文中获得的，该类属于视图层--我的项目使用了OpenSessionInView技术。

SessionFactory.getCurrentSession()方法导致了与作者相同的异常。对我来说解决办法相当简单。

Session session;

try {
    session = sessionFactory.getCurrentSession();
} catch (HibernateException e) {
    session = sessionFactory.openSession();
}

如果getCurrentSession()方法失败，则openSession()应该会成功。

Answer 2

您必须启用事务支持( 或@enableTransactionManagement)并声明TransactionManager，它应该通过SessionFactory工作。

必须将@transaction添加到@repository中

通过@repository中的@transactional，spring能够将事务性支持应用到存储库中。

您的student类没有@javax.persistence.*注释@entity，我假设这个类的映射配置是通过XML定义的。