Spring Boot API启动报错NoClassDefFoundError: javax/persistence/EntityManagerFactory

问题背景 #

我正在开发第一个Spring Boot Java API，计划实现查询所有人员、按ID查询单个人员以及创建人员的功能。编译已成功，但执行./mvnw spring-boot:run时启动失败，报错如下：

java.lang.NoClassDefFoundError: javax/persistence/EntityManagerFactory
        at org.springframework.data.jpa.util.BeanDefinitionUtils.<clinit>(BeanDefinitionUtils.java:57) ~[spring-data-jpa-2.7.18.jar:2.7.18]
        at org.springframework.data.jpa.repository.support.EntityManagerBeanDefinitionRegistrarPostProcessor.postProcessBeanFactory(EntityManagerBeanDefinitionRegistrarPostProcessor.java:72) ~[spring-data-jpa-2.7.18.jar:2.7.18]
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:325) ~[spring-context-5.3.31.jar:5.3.31]
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:191) ~[spring-context-5.3.31.jar:5.3.31]
        at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:756) ~[spring-context-5.3.31.jar:5.3.31]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:572) ~[spring-context-5.3.31.jar:5.3.31]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.18.jar:2.7.18]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.7.18.jar:2.7.18]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:409) ~[spring-boot-2.7.18.jar:2.7.18]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.18.jar:2.7.18]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) ~[spring-boot-2.7.18.jar:2.7.18]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1289) ~[spring-boot-2.7.18.jar:2.7.18]
        at com.example.demo.DemoApplication.main(DemoApplication.java:10) ~[classes/:na]
Caused by: java.lang.ClassNotFoundException: javax.persistence.EntityManagerFactory
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) ~[na:na]
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:527) ~[na:na]
        ... 13 common frames omitted

项目结构 #

.
├── mvnw
├── mvnw.cmd
├── pom.xml
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com
│   │   │       └── example
│   │   │           └── demo
│   │   │               ├── controller
│   │   │               │   └── PersonController.java
│   │   │               ├── DemoApplication.java
│   │   │               ├── model
│   │   │               │   └── Person.java
│   │   │               └── repository
│   │   │                   └── PersonRepository.java
│   │   └── resources
│   │       ├── application.properties
│   │       ├── data.sql
│   │       ├── schema.sql
│   │       ├── static
│   │       └── templates
│   └── test
└── target

相关代码 #

PersonController.java #

package com.example.demo.controller;

import com.example.demo.model.Person;
import com.example.demo.repository.PersonRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api/persons")
public class PersonController {

    @Autowired
    private PersonRepository personRepository;

    @GetMapping
    public List<Person> getAllPersons() {
        return personRepository.findAll();
    }

    @GetMapping("/{id}")
    public Person getPersonById(@PathVariable Long id) {
        return personRepository.findById(id).orElse(null);
    }

    @PostMapping
    public Person createPerson(@RequestBody Person person) {
        return personRepository.save(person);
    }
}

Person.java #

package com.example.demo.model;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import java.time.LocalDate;

@Entity
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String nom;
    private String prenom;
    private LocalDate dateNaissance;
    private String numTelephone;
    private String mail;
    
}

pom.xml配置 #

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-parent</artifactId>
       <version>2.7.18</version>
       <relativePath/>
    </parent>

    <properties>
       <java.version>11</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-web</artifactId>
       </dependency>
       <dependency>
          <groupId>com.h2database</groupId>
          <artifactId>h2</artifactId>
          <scope>runtime</scope>
       </dependency>
       <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-test</artifactId>
          <scope>test</scope>
       </dependency>
       <dependency>
          <groupId>jakarta.persistence</groupId>
          <artifactId>jakarta.persistence-api</artifactId>
          <version>3.1.0</version>
       </dependency>
       <!--<dependency>
          <groupId>javax.persistence</groupId>
          <artifactId>javax.persistence-api</artifactId>
          <version>2.2</version>
       </dependency>-->


    </dependencies>

    <build>
       <plugins>
          <plugin>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-maven-plugin</artifactId>
          </plugin>
          <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-compiler-plugin</artifactId>
             <version>3.8.1</version>
             <configuration>
                <source>11</source>
                <target>11</target>
             </configuration>
          </plugin>
       </plugins>
    </build>
</project>

尝试过的操作与疑问 #

我使用OpenJDK 11和Maven，了解到javax已被jakarta替代，因此在pom.xml中引入了jakarta.persistence-api依赖，但错误仍指向javax；尝试替换为javax.persistence-api则编译失败，恳请提供解决方案。

解决方案 #

核心问题是Spring Boot 2.x版本仅支持JPA的javax命名空间，不兼容jakarta命名空间，jakarta是Spring Boot 3.x及以上版本的标准。

步骤1：统一命名空间，改用javax.persistence #

1. 修改Person.java中的注解，将jakarta.persistence替换为javax.persistence，同时补充getter/setter方法（否则JPA和JSON序列化会失败）：

package com.example.demo.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.time.LocalDate;

@Entity
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String nom;
    private String prenom;
    private LocalDate dateNaissance;
    private String numTelephone;
    private String mail;

    // 补充getter/setter
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    public String getNom() { return nom; }
    public void setNom(String nom) { this.nom = nom; }
    public String getPrenom() { return prenom; }
    public void setPrenom(String prenom) { this.prenom = prenom; }
    public LocalDate getDateNaissance() { return dateNaissance; }
    public void setDateNaissance(LocalDate dateNaissance) { this.dateNaissance = dateNaissance; }
    public String getNumTelephone() { return numTelephone; }
    public void setNumTelephone(String numTelephone) { this.numTelephone = numTelephone; }
    public String getMail() { return mail; }
    public void setMail(String mail) { this.mail = mail; }
}

2. 修改pom.xml，移除jakarta.persistence-api依赖，无需手动引入javax.persistence-api（spring-boot-starter-data-jpa已包含该依赖，手动引入可能导致版本冲突）：

<!-- 移除jakarta依赖 -->
<!--
<dependency>
   <groupId>jakarta.persistence</groupId>
   <artifactId>jakarta.persistence-api</artifactId>
   <version>3.1.0</version>
</dependency>
-->
<!-- 注释或删除之前的javax依赖，避免重复引入 -->

步骤2：清理并重新构建 #

执行以下命令清理缓存并启动项目：

./mvnw clean install
./mvnw spring-boot:run

补充说明 #

如果想使用jakarta命名空间，需要升级到Spring Boot 3.x版本，但Spring Boot 3.x要求Java版本至少为17，需先升级Java版本到17及以上，再将pom.xml中parent版本改为3.x（如3.2.5），同时保持实体类的jakarta注解不变。

内容的提问来源于stack exchange，提问作者Guillaume