SpringBoot整合 SpringBoot data JPA

1创建数据库 user表

2.配置文件信息

#DB Configuration
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/user?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone = GMT
spring.datasource.username=root
spring.datasource.password=root
# JPAConfiguration
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true

3.entity层：

@Data
@AllArgsConstructor
@NoArgsConstructor
@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) // 主键  自增长
    private Integer uid;
    private String uname;
    private String password;

}

4：dao层：

public interface UserDao extends JpaRepository<User,Integer> {

}

5.Contrller层：

@Controller
public class HelloController {

    @Autowired
    private UserDao userDao;

　　//获取配置文件中的rows
    @Value("${page.rows}")
    private String rows;

//无需sql语句，直接调用方法即可
    @ResponseBody
    @RequestMapping("/user/list")
    public List<User> getUserList(){
        return userDao.findAll();
    }

//展示在页面
    @RequestMapping(value = "/user/list2")
    public String getUserList2(Model model){
        List<User> userList = userDao.findAll();
        model.addAttribute("userList",userList);
        return "user";
    }

    @ResponseBody
    @RequestMapping("/page/rows")
    public Map showRows(){
        Map map=new HashMap();
        map.put("rows",rows);
        return map;
    }
}

6：依赖pom.xml

freemarker:模板依赖：使用ftl文件展示数据

lombok：在实体类上使用不用生成setter,getter,tostring方法，直接使用注解

<?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>

    <groupId>com.offcn</groupId>
    <artifactId>springbootdemo1</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
    </parent>

    <dependencies>
        <!--spring MVC依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- springBoot JPA的起步依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
　　　　
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
　　
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

</project>

7.主启动类：

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

运行主启动类：

访问接口：