Controller:
@Controller:处理http请求
@RestController :返回json格式的数据。相当于@Controller+@ResponseBody
@RequestMapping:配置URL映射
@PathVariable:获取URL中的数据
//简洁请求方式:127.0.0.1:8080/hello/say/111
@RestController
@RequestMapping("/hello")
public class TestController{
@RequestMapping(value="/say/{id}",method = RequestMethod.GET)
public String say(@PathVariable("id") Integer myId){
return "id:" + myId ;
}
}
@RequestParam:获取请求参数的值
//传统请求方式:127.0.0.1:8080/hello/say?id=111
@RestController:
@RequestMapping("/hello")
public class TestController{
@RequestMapping(value="/say",method = RequestMethod.GET)
// @GetMapping(value="/say")
// public String say(@RequestParam(value="id") Integer myId){
public String say(@RequestParam(value="id",required=false,defaultValue="0") Integer myId){ //required =false 标示非必传参数
return "id:" + myId ;
}
}
@GetMapping:查询
@PostMapping 添加
@PutMapping 更新
@DeleteMapping 删除
Dao
//实体类可以自动生成表
spring:
profiles:
active: dev
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/xxx
username: root
password: 123456
jpa:
hibernate:
ddl-auto: create //注意这个create每次启动都会删除表后新建表。如果是update也会新建表,原来有相同的表里面有数据,会保留数据创建表。create-drop表示应用停下来的时候会自动删除表。none什么都不做。validate 会验证类的属性和表的字段是否一致,不一致会报错
show-sql: true
@Entity 实体类映射表
@Id
@GeneratedValue 与@Id一起加到id属性上,id自增