运行Spring Boot项目时出现Hibernate相关NullPointerException求助

构建一个Web应用，尚未添加任何自定义类或包，运行应用时抛出以下NullPointerException异常：

java.lang.NullPointerException: Cannot invoke "org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(java.sql.SQLException, String)" because the return value of "org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.sqlExceptionHelper()" is null
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:116) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentUsingJdbcMetadata(JdbcEnvironmentInitiator.java:279) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:193) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:69) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:119) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:264) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:239) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:216) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.boot.model.relational.Database.<init>(Database.java:45) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.getDatabase(InFlightMetadataCollectorImpl.java:231) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:199) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:169) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1383) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1454) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:75) ~[spring-orm-6.0.13.jar:6.0.13]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:376) ~[spring-orm-6.0.13.jar:6.0.13]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-6.0.13.jar:6.0.13]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-6.0.13.jar:6.0.13]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:352) ~[spring-orm-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1817) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1766) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:598) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:520) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.0.13.jar:6.0.13]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1166) ~[spring-context-6.0.13.jar:6.0.13]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:940) ~[spring-context-6.0.13.jar:6.0.13]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:616) ~[spring-context-6.0.13.jar:6.0.13]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.1.5.jar:3.1.5]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:738) ~[spring-boot-3.1.5.jar:3.1.5]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:440) ~[spring-boot-3.1.5.jar:3.1.5]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-3.1.5.jar:3.1.5]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-3.1.5.jar:3.1.5]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-3.1.5.jar:3.1.5]
    at com.cafemanagementsystem.CafeManagementSystemProjectApplication.main(CafeManagementSystemProjectApplication.java:10)

pom.xml文件 #

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.1.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cafemanagementsystem</groupId>
    <artifactId>CafeManagementSystemProject</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>CafeManagementSystemProject</name>
    <description>Cafe Management System Project using Spring Boot Framework.</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.yaml</groupId>
            <artifactId>snakeyaml</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

application.properties配置 #

server.port = 6969
spring.datasource.driver-class-name = com.mysql.cj.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/CafeManagementDatabase
spring.datasource.username = user
spring.datasource.password = 12345
spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = update

spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL8Dialect
spring.jpa.properties.hibernate.dialect.format_sql = true

启动类代码 #

package com.cafemanagementsystem;

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

@SpringBootApplication
public class CafeManagementSystemProjectApplication {

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

}

• 检查数据库连接有效性：确认MySQL服务正在运行，CafeManagementDatabase数据库已创建，配置的用户名user和密码12345有权限访问该数据库，同时验证MySQL服务监听的是localhost的3306端口。
• 移除冲突依赖：spring-boot-starter-data-jpa已经包含了JDBC相关的依赖支持，同时引入spring-boot-starter-jdbc可能导致依赖冲突，删除pom.xml中的spring-boot-starter-jdbc依赖项。
• 规范配置项格式：虽然Spring Boot允许配置项中有空格，但建议将配置项调整为无空格的规范格式，例如server.port=6969，避免潜在的解析问题。
• 添加实体类：Hibernate初始化时需要扫描并构建实体类的元数据，没有任何实体类会导致初始化异常。可以添加一个简单的测试实体类，示例如下：

package com.cafemanagementsystem.entity;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import lombok.Data;

@Entity
@Data
public class TestEntity {
    @Id
    private Long id;
}

• 清理重建项目：执行mvn clean install命令，清除项目缓存并重新下载依赖，确保依赖版本一致且无损坏。

内容的提问来源于stack exchange，提问作者Jawad AboFakher