SpringBoot 添加数据库的支持

前提: 项目已经配置好能通过URL获取静态数据 + mysql 数据库已经搭建好并且机器上面可以访问

参考Spring Boot官网: https://spring.io/guides/gs/accessing-data-mysql/

Step1: pom.xml添加包依赖

<dependency>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-starter-data-jpa</artifactId>

</dependency>

<dependency>

    <groupId>mysql</groupId>

    <artifactId>mysql-connector-java</artifactId>

    <scope>runtime</scope>

</dependency>

Step2: 创建 src/main/resources/application.properties, 添加如下内容

spring.jpa.hibernate.ddl-auto=none

spring.datasource.url=jdbc:mysql://localhost:3306/db_example

spring.datasource.username=springuser [注意，user这里不要用引号]

spring.datasource.password=ThePassword [注意， password这里不要用引号]

Step3: 创建 @Entity 实体 src/main/java/hello/User.java(用户根据自己的需求来新建文件)  (ORM层, 用于映射数据库字段)

package hello;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

@Entity // This tells Hibernate to make a table out of this class

public class User { 

     @Id 

     @GeneratedValue(strategy=GenerationType.AUTO) 

     private Integer id; 

     private String name; priv

     public Integer getId() { return id; }

    public void setId(Integer id) { this.id = id; } 

 }

Step4: 创建仓库(访问DB层)

package hello;

import hello.User;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.stereotype.Repository;

@Repository

public interface UserRepository extends JpaRepository<User, Long> {

}

Step5: controller 层访问数据

........

@RestController

public List<User> index() {

    return userService.findAll();

}

.........

经测试, 可以输出数据.