Hibernate sessionFactory bean抛出java.lang.NullPointerException
我的应用程序在应用程序启动时与数据库良好交互,通过会话工厂成功创建hibernate会话,并提供输出Hibernate sessionFactory bean抛出java.lang.NullPointerException,java,spring,hibernate,Java,Spring,Hibernate,我的应用程序在应用程序启动时与数据库良好交互,通过会话工厂成功创建hibernate会话,并提供输出 I am migrating jdbc to hibernate and i have palced below hibernate configuration in my application. public class HibernateConfiguration { @Bean public LocalSessionFactoryBean sessionFactory
I am migrating jdbc to hibernate and i have palced below hibernate configuration in my application.
public class HibernateConfiguration {
@Bean
public LocalSessionFactoryBean sessionFactory() {
LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
sessionFactory.setDataSource(dataSource());
sessionFactory.setPackagesToScan(new String[] { "com.cm.models" });
sessionFactory.setHibernateProperties(hibernateProperties());
return sessionFactory;
}
@Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
dataSource.setUrl(jdbcurl);
dataSource.setUsername(userName);
dataSource.setPassword(password);
return dataSource;
}
private Properties hibernateProperties() {
Properties properties = new Properties();
properties.put("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");
properties.put("hibernate.show_sql", true);
properties.put("hibernate.format_sql", true);
return properties;
}
@Bean
@Autowired
public HibernateTransactionManager transactionManager(SessionFactory s) {
HibernateTransactionManager txManager = new HibernateTransactionManager();
txManager.setSessionFactory(s);
return txManager;
}
}
但在应用程序启动后,当我通过控制器点击DAO,然后会话工厂bean获取空引用并抛出NullPointerException,因此无法创建或打开hibernate会话,我试图找出解决方案,但这不起作用,请让我知道为什么上面的SessionFactory bean由于哪个问题产生了空指针
为了测试我的DAO逻辑,我使用了这个控制器,这个控制器命中了会话facorybean为null的DAO
**@Autowired
private SessionFactory sessionFactory;**
protected Session getSession() {
return sessionFactory.getCurrentSession();
}
@RestController
@请求映射(“/Emp”)
公共类myController{
@RequestMapping(value=“/findByChannelManager”,method=RequestMethod.GET)
public void findemp(){
HotelDaoImpl HotelDaoImpl=新的HotelDaoImpl();
列表=新的ArrayList();
list=hotelDaoImpl.findByChannelManager(EnumCM.AR);
适用于(HotelEntity pro:列表){
System.out.println(pro);
}
}
}
@存储库
@交易的
公共类HotelDaoImpl扩展AbstractDao实现IHotelDao{
@SuppressWarnings({“未选中”、“未使用”})
@凌驾
公共列表FindByChannel Manager(EnumCM){
List=null;
试一试{
会话s=getSession();
标准=s.createCriteria(Hotel.class);
添加(Restrictions.eq(“channelManager”,“cm.name()”));
list=criteria.list();
}捕获(例外e){
debug(“错误”+e.getMessage());
e、 printStackTrace();
}
退货清单;
}
公共抽象类AbstractDao{
@自动连线
私人会话工厂会话工厂;
受保护会话getSession(){
返回sessionFactory.getCurrentSession();
}
}
您无法从控制器访问dao。您可以从服务访问dao,因此请添加服务类。请尝试此代码
@RestController
@RequestMapping("/Emp")
public class myController {
@RequestMapping(value = "/findByChannelManager", method = RequestMethod.GET)
public void findemp() {
HotelDaoImpl hotelDaoImpl=new HotelDaoImpl();
List <HotelEntity> list = new ArrayList<>();
list = hotelDaoImpl.findByChannelManager (EnumCM.AR);
for (HotelEntity pro : list) {
System.out.println(pro);
}
}
}
@Repository
@Transactional
public class HotelDaoImpl extends AbstractDao implements IHotelDao {
@SuppressWarnings({ "unchecked", "unused" })
@Override
public List<HotelEntity> findByChannelManager(EnumCM cm) {
List<HotelEntity> list = null;
try {
Session s = getSession();
Criteria criteria=s.createCriteria(Hotel.class);
criteria.add(Restrictions.eq("channelManager", "cm.name()"));
list = criteria.list();
}catch(Exception e) {
LOGGER.debug("error " +e.getMessage());
e.printStackTrace();
}
return list;
}
public abstract class AbstractDao {
@Autowired
private SessionFactory sessionFactory;
protected Session getSession() {
return sessionFactory.getCurrentSession();
}
}
@RestController
@请求映射(“/Emp”)
公共类myController{
@自动连线
酒店服务;
@RequestMapping(value=“/findByChannelManager”,method=RequestMethod.GET)
public void findemp(){
列表=新的ArrayList();
list=service.findByChannelManager(EnumCM.AR);
适用于(HotelEntity pro:列表){
System.out.println(pro);
}
}
}
@服务
@交易的
公共级酒店服务{
@自动连线
道道私家酒店;
公共列表FindByChannel Manager(EnumCM){
返回dao.findByChannelManager(EnumCM);
}
}
@存储库
公共类HotelDaoImpl扩展AbstractDao实现IHotelDao{
@SuppressWarnings({“未选中”、“未使用”})
@凌驾
公共列表FindByChannel Manager(EnumCM){
List=null;
试一试{
会话s=getSession();
标准=s.createCriteria(Hotel.class);
添加(Restrictions.eq(“channelManager”,“cm.name()”));
list=criteria.list();
}捕获(例外e){
debug(“错误”+e.getMessage());
e、 printStackTrace();
}
退货清单;
}
公共抽象类AbstractDao{
@自动连线
私人会话工厂会话工厂;
受保护会话getSession(){
返回sessionFactory.getCurrentSession();
}
}
能否更新控制器类?能否在post中更新,hotelDaoImpl=new hotelDaoImpl()
这可能是原因,也可以更新findByChannelManager
方法代码also@RestController@RequestMapping(“/Emp”)公共类myController{@RequestMapping(value=“/findByChannelManager”,method=RequestMethod.GET)public void findemp(){HotelDaoImpl HotelDaoImpl=new HotelDaoImpl();List List=new ArrayList();List=HotelDaoImpl.findByChannelManager(EnumCM.AR);for(HotelEntity pro:List){System.out.println(pro);}}为了测试我的DAO逻辑,我正在使用这个控制器,这个控制器在会话facory bean为空的情况下命中DAO。您正在使用new
关键字创建HotelDaoImpl
,在@controller
类中执行@Autowired
HotelDaoImpl
类
@RestController
@RequestMapping("/Emp")
public class myController {
@Autowired
HotelService service;
@RequestMapping(value = "/findByChannelManager", method = RequestMethod.GET)
public void findemp() {
List <HotelEntity> list = new ArrayList<>();
list = service.findByChannelManager (EnumCM.AR);
for (HotelEntity pro : list) {
System.out.println(pro);
}
}
}
@Service
@Transactional
public class HotelService {
@Autowired
private HotelDao dao;
public List<HotelEntity> findByChannelManager(EnumCM cm) {
return dao.findByChannelManager(EnumCM cm);
}
}
@Repository
public class HotelDaoImpl extends AbstractDao implements IHotelDao {
@SuppressWarnings({ "unchecked", "unused" })
@Override
public List<HotelEntity> findByChannelManager(EnumCM cm) {
List<HotelEntity> list = null;
try {
Session s = getSession();
Criteria criteria=s.createCriteria(Hotel.class);
criteria.add(Restrictions.eq("channelManager", "cm.name()"));
list = criteria.list();
}catch(Exception e) {
LOGGER.debug("error " +e.getMessage());
e.printStackTrace();
}
return list;
}
public abstract class AbstractDao {
@Autowired
private SessionFactory sessionFactory;
protected Session getSession() {
return sessionFactory.getCurrentSession();
}
}