我花了几个小时来尝试完成这项工作，但我总是得到相同的结果，SessionFactory 始终为空。我使用 Spring Boot 和 Hibernate 5。
我从这里和其他网页尝试了很多可能的解决方案，但我无法解决。 @Autowire 注释似乎不起作用。这是完整的代码。它太空了，因为我在项目的开始。
编辑:我已经像其他用户说的那样编辑了所有内容以进行调整，但我遇到了另一个错误。
现在错误是这样的:
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sessionConfig': Unsatisfied dependency expressed through field 'entityManagerFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'getSessionFactory' defined in class path resource [com/cibervoluntarios/app/util/SessionConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.hibernate.SessionFactory]: Circular reference involving containing bean 'sessionConfig' - consider declaring the factory method as static for independence from its containing instance. Factory method 'getSessionFactory' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:586) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:91) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:372) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1344) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868) ~[spring-context-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:138) ~[spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:751) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:387) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1245) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1233) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at com.cibervoluntarios.app.CibervoluntariosPruebas2Application.main(CibervoluntariosPruebas2Application.java:12) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'getSessionFactory' defined in class path resource [com/cibervoluntarios/app/util/SessionConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.hibernate.SessionFactory]: Circular reference involving containing bean 'sessionConfig' - consider declaring the factory method as static for independence from its containing instance. Factory method 'getSessionFactory' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:587) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1250) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1099) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1135) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:583) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
... 19 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.hibernate.SessionFactory]: Circular reference involving containing bean 'sessionConfig' - consider declaring the factory method as static for independence from its containing instance. Factory method 'getSessionFactory' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:579) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
... 31 common frames omitted
Caused by: java.lang.NullPointerException: null
at com.cibervoluntarios.app.util.SessionConfig.getSessionFactory(SessionConfig.java:16) ~[classes/:na]
at com.cibervoluntarios.app.util.SessionConfig$$EnhancerBySpringCGLIB$$870befb7.CGLIB$getSessionFactory$0(<generated>) ~[classes/:na]
at com.cibervoluntarios.app.util.SessionConfig$$EnhancerBySpringCGLIB$$870befb7$$FastClassBySpringCGLIB$$4a4fa31.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361) ~[spring-context-5.0.2.RELEASE.jar:5.0.2.RELEASE]
at com.cibervoluntarios.app.util.SessionConfig$$EnhancerBySpringCGLIB$$870befb7.getSessionFactory(<generated>) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_152]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_152]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_152]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_152]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.2.RELEASE.jar:5.0.2.RELEASE]
... 32 common frames omitted
主要
@SpringBootApplication
public class CibervoluntariosAppApplication {
private userDAO prueba;
@RequestMapping("/")
@ResponseBody
String home() {
return "Hello World. How are you?";
}
@RequestMapping("/user")
@ResponseBody
String isertuser() {
prueba = new userDAO();
users user = new users();
user.setPassword("qwerty");
BigInteger cosa = new BigInteger("12345678");
user.setSocial_id(cosa);
user.setSocial_network("Facebook");
user.setUsername("Pepe");
prueba.insertUser(user);
return "Test";
}
public static void main(String[] args) {
SpringApplication.run(CibervoluntariosAppApplication.class, args);
}
}
用户.java
@Entity
@Table(name = "users")
public class users {
@Id
@Column(name="id")
@GeneratedValue(strategy = GenerationType.AUTO)
private BigInteger id;
@Column(name = "username")
private String username;
@Column(name = "password")
private String password;
@Column(name = "social_id")
private BigInteger social_id;
@Column(name = "social_network")
private String social_network;
public BigInteger getId() {
return id;
}
public void setId(BigInteger id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public BigInteger getSocial_id() {
return social_id;
}
public void setSocial_id(BigInteger social_id) {
this.social_id = social_id;
}
public String getSocial_network() {
return social_network;
}
public void setSocial_network(String social_network) {
this.social_network = social_network;
}
}
usersDAO --> 这是 SessionFactory 具有空值的地方
@Repository
public class userDAO {
private SessionFactory sessionFactory;
public void insertUser(users user) {
Session session = null;
try {
session = sessionFactory.getCurrentSession();
session.beginTransaction();
session.save(user);
session.getTransaction().commit();
}catch (Exception e) {
session.getTransaction().rollback();
}
}
public SessionFactory getSessionFactory() {
return sessionFactory;
}
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
}
登录服务.java
@Service
public class LoginService {
@Autowired
private userDAO userManagement;
public void insertUser(users userToAdd) {
this.userManagement.insertUser(userToAdd);
}
}
登录 Controller
@RestController
@RequestMapping("/")
public class SignInController {
@Autowired
private LoginService loginService;
@RequestMapping("/hello")
@ResponseBody
public String home() {
return "Hello World. How are you?";
}
@RequestMapping("/add")
public void insertUser() {
users user = new users();
user.setPassword("qwerty");
BigInteger cosa = new BigInteger("12345678");
user.setSocial_id(cosa);
user.setSocial_network("Facebook");
user.setUsername("Pepe");
this.loginService.insertUser(user);
}
}
这是具有必要配置代码的类
@Configuration
public class SessionConfig {
@Bean
public SessionFactory sessionFactory(@Autowired EntityManagerFactory factory) {
if (factory.unwrap(SessionFactory.class) == null) {
throw new NullPointerException("factory is not a hibernate factory");
}
return factory.unwrap(SessionFactory.class);
}
}
最佳答案
你想太多了，把事情搞得很复杂。而不是普通的 Hibernate API，只需使用 JPA。您不需要 SessionConfig 抛弃它。
您的 CibervoluntariosAppApplication 应该只有 main 方法，其中的注释方法没有任何意义。
@SpringBootApplication
public class CibervoluntariosAppApplication {
public static void main(String[] args) {
SpringApplication.run(CibervoluntariosAppApplication.class, args);
}
}
现在您的 UserDao 应该使用 EntityManager(已由 Spring Boot 提供)而不是 SessionFactory。
@Repository
public class userDAO {
@PersistenceContext
private EntityManager em;
public void insertUser(users user) {
em.persist(user);
}
}
而不是手动进行事务管理，将 @Transactional 添加到您的 @Service 注释类。
@Service
@Transactional
public class LoginService {
@Autowired
private userDAO userManagement;
public void insertUser(users userToAdd) {
this.userManagement.insertUser(userToAdd);
}
}
所有这些都减少了您必须编写的代码，并且由于从您的配置中删除了不必要的 bean 而降低了复杂性。
关于java - Spring 和 Hibernate 5. SessionFactory 始终为 null，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47985260/