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@RequestMapping注解详解
@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;
@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="http://www.mamicode.com/{day}", method = RequestMethod.GET)
public Map<String, Appointment> getForDay(@PathVariable @DateTimeFormat(iso=ISO.DATE) Date day, Model model) {
return appointmentBook.getAppointmentsForDay(day);
}
@RequestMapping(value="http://www.mamicode.com/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="http://www.mamicode.com/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 = "http://www.mamicode.com/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 = "http://www.mamicode.com/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 = "http://www.mamicode.com/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 = "http://www.mamicode.com/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;
上面仅仅介绍了,RequestMapping指定的方法处理哪些请求,下面一篇将讲解怎样处理request提交的数据(数据绑定)和返回的数据。
参考资料:
1、 Spring Web Doc:
spring-3.1.0/docs/spring-framework-reference/html/mvc.html
@RequestMapping注解详解