SpringBoot(三)_controller的使用

針對controller 中 如何使用注解進行解析

@RestController

• 返回數據類型為 Json 字符串，特別適合我們給其他系統提供接口時使用。

@RequestMapping

(1) 不同前綴訪問同一個方法,此時訪問hello和hi 都可以訪問到say（）這個方法

    @RequestMapping(value = {"/hello","/hi"},method = RequestMethod.GET)
    public String say(){
        return girlProperties.getName();
    }

（2）給類一個RequestMapping, 訪問時就是：http://localhost:8099/hello/say

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Resource
    private  GirlProperties girlProperties;
    @RequestMapping(value = "/say",method = RequestMethod.GET)
    public String say(){
        return girlProperties.getName();
    }
}

@PathVariable：獲取url中的數據

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Resource
    private  GirlProperties girlProperties;
    @RequestMapping(value = "/say/{id}",method = RequestMethod.GET)
    public String say(@PathVariable("id") Integer id){
        return "id :"+id;
    }
}

訪問http://localhost:8099/hello/say/100, 結果如下

id :100

@RequestParam :獲取請求參數的值

(1) 正常請求

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Resource
    private  GirlProperties girlProperties;
    @RequestMapping(value = "/say",method = RequestMethod.GET)
    public String say(@RequestParam("id") Integer id){
        return "id :"+id;
    }
}

訪問 http://localhost:8099/hello/say?id=111 結果如下

id :111

（2）設置參數非必須的，並且設置上默認值

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Resource
    private  GirlProperties girlProperties;
    @RequestMapping(value = "/say",method = RequestMethod.GET)
    public String say(@RequestParam(value = "id",required = false,defaultValue = "0") Integer id){
        return "id :"+id;
    }
}

訪問http://localhost:8099/hello/say 結果如下

id :0

@GetMapping ，當然也有對應的Post等請求的簡化寫法

• 這里對應的就是下面這句代碼

 @GetMapping("/say")
 //等同於下面代碼
@RequestMapping(value = "/say",method = RequestMethod.GET)