java - 上下文初始化期间遇到异常 - 取消刷新尝试 : UnsatisfiedDependencyException

Question

错误:

Exception encountered during context initialization - cancelling refresh attempt: 
org.springframework.beans.factory.UnsatisfiedDependencyException: 
Error creating bean with name 'homeController': 
Unsatisfied dependency expressed through field 'postService'; 
nested exception is org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'postService': Injection of persistence dependencies failed; 
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [TechnicalBlogApp/config/JpaConfig.class]: 
Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: 
Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; 
nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; 
nested exception is org.hibernate.MappingException: 
Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister

这是我的示例文件:

TechnicalBlogApp 主类:

package TechnicalBlogApp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication


public class TechnicalBlogApp {
    public static void main(String [] args){
        SpringApplication.run(TechnicalBlogApp.class, args);
    }

}

HomeController 类:

package TechnicalBlogApp.controller;

import TechnicalBlogApp.model.Post;
import TechnicalBlogApp.service.PostService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.List;


@Controller
public class HomeController {

    public HomeController() {
        System.out.println("*** HomeController ***");
    }

    @Autowired
    private PostService postService;

    @RequestMapping("/")
    public String getAllPosts(Model model) {

        List<Post> posts = postService.getAllPosts();

        model.addAttribute("posts", posts);

        return "index";

    }

}

PostService 类:

package TechnicalBlogApp.service;


import TechnicalBlogApp.model.Post;

import org.springframework.stereotype.Service;

import javax.persistence.*;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

@Service
public class PostService {

    @PersistenceUnit(unitName = "techblog")
    private EntityManagerFactory emf;


     public PostService() {
        System.out.println("*** PostService ***");
    }

    public List<Post> getAllPosts() {
        List<Post> posts = new ArrayList<>();
        EntityManager em = emf.createEntityManager();
        TypedQuery<Post> query = em.createQuery("SELECT p from Post p",Post.class);
        List<Post> resultList = query.getResultList();


        return resultList;
    }

}

课后(模型):

package TechnicalBlogApp.model;
import javax.persistence.*;

import java.util.Date;



@Entity
@Table(name = "posts")
public class Post {


    @Id
    @Column(name = "id")
    private Integer id;

    @Column(name = "title")
    private String title;

    @Column(name = "body")
    private String body;

    private Date date;


    public Integer getId() {
        return id;
    }

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

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }
}

JPA配置类:

package TechnicalBlogApp.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

@Configuration
public class JpaConfig {

    @Bean
    public EntityManagerFactory entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean emfb  = new LocalContainerEntityManagerFactoryBean();
        emfb.setPersistenceXmlLocation("classpath:META-INF/persistence.xml");
        emfb.afterPropertiesSet();

        return emfb.getObject();
    }

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource ds = new DriverManagerDataSource();
        ds.setDriverClassName("org.postgresql.Driver");
        ds.setUrl("jdbc:postgresql://localhost:5432/technicalblog1");
        ds.setUsername("postgres");
        ds.setPassword("eposa");
        return ds;
    }
}

META-INF > persistence.xml 文件:

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
            http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
             version="2.1">

    <persistence-unit name="techblog">

        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

        <properties>

            <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/technicalblog1" />
            <property name="javax.persistence.jdbc.user" value="postgres" />
            <property name="javax.persistence.jdbc.password" value="eposa" />

            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL82Dialect" />
            <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/>
        </properties>

    </persistence-unit>

</persistence>

POM.xml(Maven):

<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">
        <modelVersion>4.0.0</modelVersion>

    <groupId>org.avi</groupId>
    <artifactId>TechnicalBlogApp</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>TechnicalBlogApp Tapestry 5 Application</name>


    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/>
    </parent>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.2</version>
            <scope>runtime</scope>
        </dependency>

    </dependencies>

</project>

当我不使用数据库连接并直接从 PostService 类生成数据时，此代码工作正常。我还在 intellij view>tools>database>add DB postgres 中连接到我的数据库，测试连接工作正常。

My project in IDE

完整的错误跟踪:

Exception encountered during context initialization - cancelling refresh attempt: 
org.springframework.beans.factory.UnsatisfiedDependencyException: 
Error creating bean with name 'homeController': 
Unsatisfied dependency expressed through field 'postService'; 
nested exception is org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'postService': Injection of persistence dependencies failed; 
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [TechnicalBlogApp/config/JpaConfig.class]: 
Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: 
Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; 
nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; 
nested exception is org.hibernate.MappingException: 
Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister


Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-02-29 10:18:29.889 ERROR 7284 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'homeController': Unsatisfied dependency expressed through field 'postService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'postService': Injection of persistence dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [TechnicalBlogApp/config/JpaConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:586) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:372) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1341) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
    at TechnicalBlogApp.TechnicalBlogApp.main(TechnicalBlogApp.java:12) ~[classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'postService': Injection of persistence dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [TechnicalBlogApp/config/JpaConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:356) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1341) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1135) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:583) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    ... 19 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [TechnicalBlogApp/config/JpaConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:590) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1247) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1096) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:535) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.findEntityManagerFactory(EntityManagerFactoryUtils.java:108) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findNamedEntityManagerFactory(PersistenceAnnotationBeanPostProcessor.java:549) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findEntityManagerFactory(PersistenceAnnotationBeanPostProcessor.java:529) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.resolveEntityManagerFactory(PersistenceAnnotationBeanPostProcessor.java:686) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.getResourceToInject(PersistenceAnnotationBeanPostProcessor.java:677) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:180) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:353) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    ... 30 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManagerFactory]: Factory method 'entityManagerFactory' threw exception; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:582) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    ... 46 common frames omitted
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: techblog] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:402) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at TechnicalBlogApp.config.JpaConfig.entityManagerFactory(JpaConfig.java:18) ~[classes/:na]
    at TechnicalBlogApp.config.JpaConfig$$EnhancerBySpringCGLIB$$e9ffbdd9.CGLIB$entityManagerFactory$1(<generated>) ~[classes/:na]
    at TechnicalBlogApp.config.JpaConfig$$EnhancerBySpringCGLIB$$e9ffbdd9$$FastClassBySpringCGLIB$$f25883a7.invoke(<generated>) ~[classes/:na]
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:365) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at TechnicalBlogApp.config.JpaConfig$$EnhancerBySpringCGLIB$$e9ffbdd9.entityManagerFactory(<generated>) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    ... 47 common frames omitted
Caused by: org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:123) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.metamodel.internal.MetamodelImpl.initialize(MetamodelImpl.java:129) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:300) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:462) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:151) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.0.9.RELEASE.jar:5.0.9.RELEASE]

Answer 1

在您的 JPA 实体 中，您需要在 Post 类中创建一个无参数构造函数。

constructor is required to have Hibernate initialize the entity; private is allowed but package-private (or public) visibility is required for runtime proxy generation and efficient data retrieval without bytecode instrumentation.

如果您使用的是 Java 11 或更高版本，javassist 应该位于类路径上

<dependency>
    <groupId>org.javassist</groupId>
    <artifactId>javassist</artifactId>
    <version>3.23.1-GA</version>
</dependency>