Controller的使用

1. 使用Controller必须添加注解

   @Controller
   public class DemoController{
   ...
   }
   

2. RestController的使用

   @RestController
   public class DemoController{
   ...
   }
   

3. RequestMapping类型

   #给类添加一个总体roule
   @RequestMapping("/index")
   #给方法添加一个roule
   @RequestMapping(value = "/hello", method = RequestMethod.GET)
   #给方法添加多处roule
   @RequestMapping(value = {"/hello", "demo"}, method = RequestMethod.GET)
   

4. 获取请求参数

@PathVariable
#通过/product/xxx传参数
@RequestMapping(value = "/product1/{name}", method = RequestMethod.GET)
public String product1(@PathVariable("name") String name) {
    return "Product1:" + name;
}

#通过?name=xxx传参数
@RequestMapping(value = "/product", method = RequestMethod.GET)
public String product(@PathVariable("name") String name) {
    return "Product:" + name;
}


@RequestParam
@RequestParam(value="username", required = false, defaultValue = 0)
value 请求字段名
required 是否居必传
defaultValue 默认值

@GetMapping
@GetMapping("/product")
对注解进行了有效的缩写，它等同于
@RequestMapping(value = "/product", method = RequestMethod.GET)
当然还有
@PostMapping
@PutMapping
...