springboot2.0 + jpa + mysql

1. idea new project,勾选 web， jpa 和mysql

pom内容如下：

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-data-jpaartifactId>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-webartifactId>
dependency>

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <scope>runtimescope>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-testartifactId>
    <scope>testscope>
dependency>
<dependency>
    <groupId>org.apache.commonsgroupId>
    <artifactId>commons-lang3artifactId>
    <version>3.4version>
dependency>

2. 修改application.properties

server.port = 8080

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/jpa
spring.datasource.username= root
spring.datasource.password= xxxx0510
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.jpa.database=mysql
# 显示后台处理的SQL语句
spring.jpa.show-sql=true
# 自动检查实体和数据库表是否一致，如果不一致则会进行更新数据库表
spring.jpa.hibernate.ddl-auto=update

3. 编写实体类

@Entity
@Table(name="employee")
public class Employee {
    @Id
    @Column(name="id")
    private String id;

    @Column(name="name")
    private String name;

    @Column(name="gender")
    private String gender;

    @Column(name="age")
    private int age;

...getter setter方法代码略}

4. 编写dao层接口

public interface EmployeeRepository extends JpaRepository {

}

5.编写controller代码

@RestController
@RequestMapping("/employee")
public class EmployeeController {

    @Autowired
    private EmployeeRepository employeeRepository;

    @RequestMapping("/queryall")
    @ResponseBody
    public List queryAll(){
        List list = new ArrayList();
        list = employeeRepository.findAll();
        return list;
    }

@RequestMapping("/querybyid")
@ResponseBody
public Employee queryById(@RequestParam String id){
    Employee employee = employeeRepository.findById(id).get();
    return employee;
}

findById返回后，需要用get()方法获取实际返回的值。

6. 打包运行测试

7. demo代码地址：https://github.com/wuxidemo/springjpa