Springmvc中@RequestMapping 属性用法归纳

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（分成三类进行说明）与六个基本用法，

一、属性

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。

1、value  / method 示例

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

@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)

@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)

@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：

@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：

@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：

@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：

@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；

二、用法

1）最基本的，方法级别上应用，例如：

@RequestMapping(value="/departments")
public String simplePattern(){  

  System.out.println("simplePattern method was called");
  return "someResult";  

}  

则访问http://localhost/xxxx/departments的时候，会调用 simplePattern方法了 
2） 参数绑定

@RequestMapping(value="/departments")
public String findDepatment(
  @RequestParam("departmentId") String departmentId){  

    System.out.println("Find department with ID: " + departmentId);
    return "someResult";  

}  

形如这样的访问形式： 
   /departments?departmentId=23就可以触发访问findDepatment方法了 
3 REST风格的参数

@RequestMapping(value="/departments/{departmentId}")
public String findDepatment(@PathVariable String departmentId){  

  System.out.println("Find department with ID: " + departmentId);
  return "someResult";  

}  

形如REST风格的地址访问，比如： 
/departments/23，其中用(@PathVariable接收rest风格的参数

4 REST风格的参数绑定形式之2 
   先看例子，这个有点象之前的：

@RequestMapping(value="/departments/{departmentId}")
public String findDepatmentAlternative(
  @PathVariable("departmentId") String someDepartmentId){  

    System.out.println("Find department with ID: " + someDepartmentId);
    return "someResult";  

}  

这个有点不同，就是接收形如/departments/23的URL访问，把23作为传入的departmetnId,，但是在实际的方法findDepatmentAlternative中，使用 
@PathVariable("departmentId") String someDepartmentId，将其绑定为 
someDepartmentId,所以这里someDepartmentId为23

5 url中同时绑定多个id

@RequestMapping(value="/departments/{departmentId}/employees/{employeeId}")
public String findEmployee(
  @PathVariable String departmentId,
  @PathVariable String employeeId){  

    System.out.println("Find employee with ID: " + employeeId +
      " from department: " + departmentId);
    return "someResult";  

}  

6 支持正则表达式

@RequestMapping(value="/{textualPart:[a-z-]+}.{numericPart:[\\d]+}")
public String regularExpression(
  @PathVariable String textualPart,
  @PathVariable String numericPart){  

    System.out.println("Textual part: " + textualPart +
      ", numeric part: " + numericPart);
    return "someResult";
}  

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