@RequestMapping注解实践

1.引言

springMVC提供了http请求的注解，功能强大，对http协议的封装实现妙到恰好。本文重点学习@RequestMapping注解，一起感受springMVC的强大和精深。

http协议有post和put方式提交数据，但是它们到底有什么不同呢？通过实践理解它们的不同之处。

2.简介

@RequestMapping

它是一个用来处理请求地址映射的注解。可用于类和方法上。用于类上，表示类中所有请求的方法都是以该地址作为父路径。RequestMapping有6个属性，分三类说明：

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)类型中包含指定类型才返回；

3.params,headers

params:指定request中必须包含某些参数值，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。

 

4.示例

1.value / method 示例

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

@Controller  
@RequestMapping("/appointments")  
public class AppointmentsController {  
  
    private final 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）

exampleB

@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";   
}  

 exampleC

@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

consumes的示例：

@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的示例：

@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请求总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的示例：

@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”,职位“myValue”的请求；

headers的示例：

@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；

 

 实践1

@RequestMapping(value="userInfo",params={"param"},method=RequestMethod.PUT,consumes="application/json",produces="application/json")
		@ResponseBody
		public String userInfo(String param,HttpServletRequest request,HttpServletResponse response,HttpSession session){
			log.info(param);
			return param;
			
		}

 发送param参数给服务器，param参数符合json格式。

 

 

参考：http://blog.csdn.net/walkerjong/article/details/7994326#