Spring Boot访问mysql(JPA方式)最简单配置

0.先推荐一个工具——lombok,pom文件如下：

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <scope>compile</scope>
</dependency>

可以使用注解@Data 编译时自动生成get,set方法,构造函数,toString方法。

@Data
@Entity
public class Account
{
    @Id
    private String id;
    private String account;
    @Column(name = "call_phone")
    private String phone;
    @Column(name = "nick_name")
    private String nickname;
    private String password;
    private String salt;
    private int userType;
    private String createUser;
    private Timestamp createTime;
    private int state;
}

生成后的效果如下：

1.pom.xml文件下添加如下依赖，引入spring-boot-jpa的jar包，以及mysql驱动

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

2.在/src/main/resources/application.properties中配置spring datasource及hibernate方言

(Spring boot 默认使用hibernate作为JPA的实现)

spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.tomcat.max-active=100
spring.datasource.tomcat.max-idle=200
spring.datasource.tomcat.initialSize=20
spring.jpa.database-platform=org.hibernate.dialect.MySQL5Dialect

3.定义Entity和Repository(接口)。

Entity--Account实体类如下:

@Entity会被spring扫描并加载，

@Id注解在主键上

@Column name="call_phone" 指该字段对应的数据库的字段名，如果相同就不需要定义。数据库下划线间隔和代码中的驼峰法视为相同，如数据库字段create_time等价于Java类中的createTime，因此不需要用@Column注解。

@Data
@Entity
public class Account
{
    @Id
    private String id;
    private String account;
    @Column(name = "call_phone")
    private String phone;
    @Column(name = "nick_name")
    private String nickname;
    private String password;
    private String salt;
    private int userType;
    private String createUser;
    private Timestamp createTime;
    private int state;
}

Repository如下：

@Repository
public interface AccountRepository extends JpaRepository<Account, String>
{
    Account findOneByAccount(String account);
}

4.在其他@Component中调用

@RestController
@RequestMapping("/subsystem")
public class SubsystemAuthorityService
{
    @Autowired
    AccountRepository accountRepository;

    @PostMapping(path = "/admin/info")
    public String getAdminInfo(String currentAccount)
    {
        Account account = accountRepository.findOneByAccount(currentAccount);
        System.out.println(account);
        return account.toString();
    }
}