Spring 基本注解

传参接受注解

传参方式	示例	注解
路径	/user/1	@PathVariable("id") Integer id
请求体	{ "name": "张三" }	@RequestBody User user
请求参数	/user?id=1	@RequestParam("id") Integer id
表单传文件	<form action="/upload" method="post" enctype="multipart/form-data">	@RequestParam("file") MultipartFile file
请求头	/user	@RequestHeader("token") String token

@RestController注解

@RestController

@RestController注解相当于@Controller和@ResponseBody的结合，返回的数据不会被解析为跳转路径，而是直接写入HTTP response body中。一般在异步获取数据时使用，在使用@RequestMapping后，返回值通常解析为跳转路径，加上@ResponseBody后返回结果不会被解析为跳转路径，而是直接写入HTTP response body中。比如异步获取json数据，加上@ResponseBody后，会直接返回json数据。

@RestController
public class UserController {

    @RequestMapping("/list")
    public String list() {
        return "list";
    }

    @RequestMapping("/add")
    public String add() {
        return "add";
    }
}

@RequestMapping注解

@RequestMapping

@RequestMapping注解是一个用来处理请求地址映射的注解，可用于类或方法上。用于类上，表示类中的所有响应请求的方法都是以该地址作为父路径。

@RestController
@RequestMapping("/user")
public class UserController {

    @RequestMapping("/list")
    public String list() {
        return "list";
    }

    @RequestMapping("/add")
    public String add() {
        return "add";
    }
}

@GetMapping、@PostMapping、@PutMapping、@DeleteMapping注解

@GetMapping

• @GetMapping注解是@RequestMapping(method = RequestMethod.GET)的缩写。

• @PostMapping注解是@RequestMapping(method = RequestMethod.POST)的缩写。

• @PutMapping注解是@RequestMapping(method = RequestMethod.PUT)的缩写。

• @DeleteMapping注解是@RequestMapping(method = RequestMethod.DELETE)的缩写。

@RestController
@RequestMapping("/user")
public class UserController {

    @GetMapping("/list")
    public String list() {
        return "list";
    }

    @PostMapping("/add")
    public String add() {
        return "add";
    }
}

1,防止重复提交注解

// AvoidRepeatSubmit.java
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface AvoidRepeatSubmit {

    long time() default 3;
}

2,创建切片类实现

// AvoidRepeatSubmitAspect.java
@Aspect
@Component
@Slf4j
public class AvoidRepeatSubmitAspect {

    @Resource
    RedisCache redisCache;

    @Before("@annotation(com.yangliwei.product.annotation.AvoidRepeatSubmit)")
    public void repeatSubmitIntercept(JoinPoint joinPoint){
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        String ip = WebUtil.IpAddressUtils(request);
        String className = joinPoint.getTarget().getClass().getName();
        String methodName = joinPoint.getSignature().getName();
        AvoidRepeatSubmit avoidRepeatSubmit = this.getAvoidRepeatSubmit(joinPoint);
        long time = avoidRepeatSubmit.time();
        String key = ip + className + methodName;
        log.info("key:{}",key);
        String value = redisCache.getCacheObject(key);
        if (value != null) {
            throw new CustomException(500,"请勿重复提交");
        }
        redisCache.setCacheObject(key,key, time, TimeUnit.SECONDS);
    }

    private AvoidRepeatSubmit getAvoidRepeatSubmit(JoinPoint joinPoint) {
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        return methodSignature.getMethod().getAnnotation(AvoidRepeatSubmit.class);
    }
}

// 查询ip地址

    public static String IpAddressUtils(HttpServletRequest request){
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

3,使用

// HelloController.java
@GetMapping("hello")
@AvoidRepeatSubmit(time = 5)
public String hello(){
    return "hello world";
}