如何将Spring Boot与MySQL数据库和JPA一起使用？

java mysql spring jpa spring-boot

2022-09-01 12:15:31

我想用MySQL和JPA设置Spring Boot。为此，我创建：人

package domain;

import javax.persistence.*;

@Entity
@Table(name = "person")
public class Person {

@Id
@GeneratedValue
private Long id;

@Column(nullable = false)
private String firstName;

// setters and getters
}

人员存储库

package repository;

import domain.Person;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;


public interface PersonRepository extends CrudRepository<Person, Long> {

Page<Person> findAll(Pageable pageable);
}

人员控制器

package controller;

import domain.Person;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import repository.PersonRepository;

@Controller
public class PersonController {

@Autowired
private PersonRepository personRepository;

@RequestMapping("/")
@ResponseBody
public String test() {
    Person person = new Person();
    person.setFirstName("First");
    person.setLastName("Test");
    personRepository.save(person);
    return "hello";
}
}

启动类示例：

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

@SpringBootApplication
public class Example {

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

}

对于数据库配置，我创建了 application.properties

spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.properties.hibernate.globally_quoted_identifiers=true

spring.datasource.url=jdbc:mysql://localhost/test_spring_boot
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driverClassName=com.mysql.jdbc.Driver

所以我有项目结构：

enter image description here

但结果是我有例外：

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [Example]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/security/config/annotation/authentication/configurers/GlobalAuthenticationConfigurerAdapter.class] cannot be opened because it does not exist

作为我使用的示例：spring-boot-sample-data-jpa/pom.xml

答案 1

我像你一样创建了一个项目。结构看起来像这样

project structure

类只是从您的类复制粘贴。

我将 application.properties 更改为：

spring.datasource.url=jdbc:mysql://localhost/testproject
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

但我认为你的问题在于你的pom.xml：

<?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 http://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>1.4.1.RELEASE</version>
</parent>

<artifactId>spring-boot-sample-jpa</artifactId>
<name>Spring Boot JPA Sample</name>
<description>Spring Boot JPA Sample</description>

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
</dependencies>
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

检查这些文件是否存在差异。希望这有帮助

更新 1：我更改了用户名。该示例的链接现在 https://github.com/Yannic92/stackOverflowExamples/tree/master/SpringBoot/MySQL

答案 2

当将类移动到特定的包（如存储库，控制器，域）中时，仅泛型是不够的。@SpringBootApplication

您必须指定组件扫描的基本包

@ComponentScan("base_package")

对于 JPA

@EnableJpaRepositories(basePackages = "repository")

也是必需的，因此 Spring 数据将知道在何处查找存储库接口。