Spring Boot学习（一）之Controller的使用

@Controller:处理http请求

@RestController：

@RestController注解相当于@ResponseBody ＋ @Controller合在一起的作用。Spring4之后新加入的注解，原来返回json需要@ResponseBody配合@Controller

@RequestMapping:配置url映射，可用于用户通过某个url访问到我们写的方法

例子：

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

   @Autowired
   private GirlProperties girlProperties;

    @RequestMapping(value = "/say",method = RequestMethod.POST)
    public String say(){
        return girlProperties.getCupSize();
    }
}

@PathVariable:获取url中的数据

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

仔细看url，后面的参数比起传统的更加简洁，传统get方法获取参数如下面所示

@RequestParam:获取请求参数的值

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

   @Autowired
   private GirlProperties girlProperties;

    @RequestMapping(value = "/say",method = RequestMethod.GET)

    public String say(@RequestParam("id") Integer myid){
        return "id"+myid;
    }
}

public String say(@RequestParam(value = "id",required = false,defaultValue = "0") Integer id){
    return "id"+id;
}

@GetMapping:组合注解

//@RequestMapping(value = "/say",method = RequestMethod.GET)
@GetMapping(value = "/say")