基于@RequestMapping 用法详解之地址映射

时间:2022-08-24 21:04:34

@RequestMapping之地址映射

引言:

前段时间项目中用到了RESTful模式来开发程序,但是当用POST、PUT模式提交数据时,发现服务器端接受不到提交的数据(服务器端参数绑定没有加任何注解),查看了提交方式为application/json, 而且服务器端通过request.getReader() 打出的数据里确实存在浏览器提交的数据。

为了找出原因,便对参数绑定(@RequestParam、 @RequestBody、 @RequestHeader 、 @PathVariable)进行了研究,同时也看了一下HttpMessageConverter的相关内容,在此一并总结。

简介:

@RequestMapping

RequestMapping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。

RequestMapping注解有六个属性,下面我们把她分成三类进行说明。

1、value, method;

  • value:指定请求的实际地址,指定的地址可以是URI Template 模式(后面将会说明);
  • method:指定请求的method类型, GET、POST、PUT、DELETE等;

2、consumes,produces;

  • consumes:指定处理请求的提交内容类型(Content-Type),例如application/json, text/html;
  • produces:指定返回的内容类型,仅当request请求头中的(Accept)类型中包含该指定类型才返回;

3、 params,headers;

  • params:指定request中必须包含某些参数值是,才让该方法处理。
  • headers:指定request中必须包含某些指定的header值,才能让该方法处理请求。

示例:

1、value / method 示例

默认RequestMapping("....str...")即为value的值;

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@Controller
@RequestMapping("/appointments")
public class AppointmentsController {
    private AppointmentBook appointmentBook;   
    @Autowired
    public AppointmentsController(AppointmentBook appointmentBook) {
        this.appointmentBook = appointmentBook;
    }
 
    @RequestMapping(method = RequestMethod.GET)
    public Map<String, Appointment> get() {
        return appointmentBook.getAppointmentsForToday();
    }
 
    @RequestMapping(value="/{day}", method = RequestMethod.GET)
    public Map<String, Appointment> getForDay(@PathVariable @DateTimeFormat(iso=ISO.DATE) Date day, Model model) {
        return appointmentBook.getAppointmentsForDay(day);
    }
 
    @RequestMapping(value="/new", method = RequestMethod.GET)
    public AppointmentForm getNewForm() {
        return new AppointmentForm();
    }
 
    @RequestMapping(method = RequestMethod.POST)
    public String add(@Valid AppointmentForm appointment, BindingResult result) {
        if (result.hasErrors()) {
            return "appointments/new";
        }
        appointmentBook.addAppointment(appointment);
        return "redirect:/appointments";
    }
}

value的uri值为以下三类:

A) 可以指定为普通的具体值;

B) 可以指定为含有某变量的一类值(URI Template Patterns with Path Variables);

C) 可以指定为含正则表达式的一类值( URI Template Patterns with Regular Expressions);

example B)

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@RequestMapping(value="/owners/{ownerId}", method=RequestMethod.GET)
public String findOwner(@PathVariable String ownerId, Model model) {
  Owner owner = ownerService.findOwner(ownerId); 
  model.addAttribute("owner", owner); 
  return "displayOwner";
}

example C)

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@RequestMapping("/spring-web/{symbolicName:[a-z-]+}-{version:\d\.\d\.\d}.{extension:\.[a-z]}")
  public void handle(@PathVariable String version, @PathVariable String extension) {   
    // ...
  }
}

2 consumes、produces 示例

cousumes的样例:

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@Controller
@RequestMapping(value = "/pets", method = RequestMethod.POST, consumes="application/json")
public void addPet(@RequestBody Pet pet, Model model) {   
    // implementation omitted
}

方法仅处理request Content-Type为“application/json”类型的请求。

produces的样例:

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@Controller
@RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, produces="application/json")
@ResponseBody
public Pet getPet(@PathVariable String petId, Model model) {   
    // implementation omitted
}

方法仅处理request请求中Accept头中包含了"application/json"的请求,同时暗示了返回的内容类型为application/json;

3 params、headers 示例

params的样例:

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@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController {
 
  @RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, params="myParam=myValue")
  public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {   
    // implementation omitted
  }
}

仅处理请求中包含了名为“myParam”,值为“myValue”的请求;

headers的样例:

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@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController {
 
@RequestMapping(value = "/pets", method = RequestMethod.GET, headers="Referer=http://www.ifeng.com/")
  public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {   
    // implementation omitted
  }
}

仅处理request的header中包含了指定“Refer”请求头和对应值为“http://www.ifeng.com/”的请求;

上面介绍了,RequestMapping指定的方法处理哪些请求,以上为个人经验,希望能给大家一个参考,也希望大家多多支持服务器之家。

原文链接:https://blog.csdn.net/walkerJong/article/details/7994326