原文地址:
@RequestMapping is one of the most widely used Spring MVC annotation.org.springframework.web.bind.annotation.RequestMapping
annotation is used to map web requests onto specific handler classes and/or handler methods.
@RequestMapping
can be applied to the controller class as well as methods. Today we will look into various usage of this annotation with example.
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@Controller
@RequestMapping
(
"/home"
)
public
class
HomeController {
}
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Now /home is the URI for which this controller will be used. This concept is very similar to servlet context of a web application.
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@RequestMapping
(value=
"/method0"
)
@ResponseBody
public
String method0(){
return
"method0"
;
}
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Above annotation can also be written as @RequestMapping("/method0")
. On a side note, I am using @ResponseBody to send the String response for this web request, this is done to keep the example simple. Like I always do, I will use these methods in Spring MVC application and test them with a simple program or script.
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@RequestMapping
(value={
"/method1"
,
"/method1/second"
})
@ResponseBody
public
String method1(){
return
"method1"
;
}
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If you will look at the source code of RequestMapping annotation, you will see that all of it’s variables are arrays. We can create String array for the URI mappings for the handler method.
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@RequestMapping
(value=
"/method2"
, method=RequestMethod.POST)
@ResponseBody
public
String method2(){
return
"method2"
;
}
@RequestMapping
(value=
"/method3"
, method={RequestMethod.POST,RequestMethod.GET})
@ResponseBody
public
String method3(){
return
"method3"
;
}
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@RequestMapping
(value=
"/method4"
, headers=
"name=pankaj"
)
@ResponseBody
public
String method4(){
return
"method4"
;
}
@RequestMapping
(value=
"/method5"
, headers={
"name=pankaj"
,
"id=1"
})
@ResponseBody
public
String method5(){
return
"method5"
;
}
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Content-Type
and Accept
to find out request contents and what is the mime message it wants in response. For clarity, @RequestMapping provides produces and consumes variables where we can specify the request content-type for which method will be invoked and the response content type. For example:
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@RequestMapping
(value=
"/method6"
, produces={
"application/json"
,
"application/xml"
}, consumes=
"text/html"
)
@ResponseBody
public
String method6(){
return
"method6"
;
}
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Above method can consume message only with Content-Type as text/html and is able to produce messages of type application/json and application/xml.
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@RequestMapping
(value=
"/method7/{id}"
)
@ResponseBody
public
String method7(
@PathVariable
(
"id"
)
int
id){
return
"method7 with id="
+id;
}
@RequestMapping
(value=
"/method8/{id:[\\d]+}/{name}"
)
@ResponseBody
public
String method8(
@PathVariable
(
"id"
)
long
id,
@PathVariable
(
"name"
) String name){
return
"method8 with id= "
+id+
" and name="
+name;
}
|
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@RequestMapping
(value=
"/method9"
)
@ResponseBody
public
String method9(
@RequestParam
(
"id"
)
int
id){
return
"method9 with id= "
+id;
}
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For this method to work, the parameter name should be “id” and it should be of type int.
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@RequestMapping
()
@ResponseBody
public
String defaultMethod(){
return
"default method"
;
}
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As you have seen above that we have mapped /home
to HomeController
, this method will be used for the default URI requests.
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@RequestMapping
(
"*"
)
@ResponseBody
public
String fallbackMethod(){
return
"fallback method"
;
}
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We can use Spring RestTemplate to test the different methods above, but today I will use cURL commands to test these methods because these are simple and there are not much data flowing around.
I have created a simple shell script to invoke all the above methods and print their output. It looks like below.
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#!/bin/bash
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method0"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method0
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/xyz"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/xyz
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method1"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method1
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method1/second"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method1/second
;
printf
"\n\n*****\n\n"
;
echo
"curl -X POST http://localhost:9090/SpringRequestMappingExample/home/method2"
;
curl -X POST http:
//localhost
:9090
/SpringRequestMappingExample/home/method2
;
printf
"\n\n*****\n\n"
;
echo
"curl -X POST http://localhost:9090/SpringRequestMappingExample/home/method3"
;
curl -X POST http:
//localhost
:9090
/SpringRequestMappingExample/home/method3
;
printf
"\n\n*****\n\n"
;
echo
"curl -X GET http://localhost:9090/SpringRequestMappingExample/home/method3"
;
curl -X GET http:
//localhost
:9090
/SpringRequestMappingExample/home/method3
;
printf
"\n\n*****\n\n"
;
echo
"curl -H "
name:pankaj
" http://localhost:9090/SpringRequestMappingExample/home/method4"
;
curl -H
"name:pankaj"
http:
//localhost
:9090
/SpringRequestMappingExample/home/method4
;
printf
"\n\n*****\n\n"
;
echo
"curl -H "
name:pankaj
" -H "
id
:1
" http://localhost:9090/SpringRequestMappingExample/home/method5"
;
curl -H
"name:pankaj"
-H
"id:1"
http:
//localhost
:9090
/SpringRequestMappingExample/home/method5
;
printf
"\n\n*****\n\n"
;
echo
"curl -H "
Content-Type:text
/html
" http://localhost:9090/SpringRequestMappingExample/home/method6"
;
curl -H
"Content-Type:text/html"
http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method6"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
;
printf
"\n\n*****\n\n"
;
echo
"curl -H "
Content-Type:text
/html
" -H "
Accept:application
/json
" -i http://localhost:9090/SpringRequestMappingExample/home/method6"
;
curl -H
"Content-Type:text/html"
-H
"Accept:application/json"
-i http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
;
printf
"\n\n*****\n\n"
;
echo
"curl -H "
Content-Type:text
/html
" -H "
Accept:application
/xml
" -i http://localhost:9090/SpringRequestMappingExample/home/method6"
;
curl -H
"Content-Type:text/html"
-H
"Accept:application/xml"
-i http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method7/1"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method7/1
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method8/10/Lisa"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method8/10/Lisa
;
printf
"\n\n*****\n\n"
;
echo
"curl http://localhost:9090/SpringRequestMappingExample/home/method9?id=20"
;
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method9
?
id
=20;
printf
"\n\n*****DONE*****\n\n"
;
|
Note that I have deployed my web application on Tomcat-7 and it’s running on port 9090.SpringRequestMappingExample is the servlet context of the application. Now when I execute this script through command line, I get following output.
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pankaj:~ pankaj$ .
/springTest
.sh
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method0
method0
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home
default method
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/xyz
fallback method
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method1
method1
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method1/second
method1
*****
curl -X POST http:
//localhost
:9090
/SpringRequestMappingExample/home/method2
method2
*****
curl -X POST http:
//localhost
:9090
/SpringRequestMappingExample/home/method3
method3
*****
curl -X GET http:
//localhost
:9090
/SpringRequestMappingExample/home/method3
method3
*****
curl -H name:pankaj http:
//localhost
:9090
/SpringRequestMappingExample/home/method4
method4
*****
curl -H name:pankaj -H
id
:1 http:
//localhost
:9090
/SpringRequestMappingExample/home/method5
method5
*****
curl -H Content-Type:text
/html
http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
method6
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
fallback method
*****
curl -H Content-Type:text
/html
-H Accept:application
/json
-i http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
HTTP
/1
.1 200 OK
Server: Apache-Coyote
/1
.1
Content-Type: application
/json
Content-Length: 7
Date: Thu, 03 Jul 2014 18:14:10 GMT
method6
*****
curl -H Content-Type:text
/html
-H Accept:application
/xml
-i http:
//localhost
:9090
/SpringRequestMappingExample/home/method6
HTTP
/1
.1 200 OK
Server: Apache-Coyote
/1
.1
Content-Type: application
/xml
Content-Length: 7
Date: Thu, 03 Jul 2014 18:14:10 GMT
method6
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method7/1
method7 with
id
=1
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method8/10/Lisa
method8 with
id
= 10 and name=Lisa
*****
curl http:
//localhost
:9090
/SpringRequestMappingExample/home/method9
?
id
=20
method9 with
id
= 20
*****DONE*****
pankaj:~ pankaj$
|
Most of these are self understood, although you might want to check default and fallback methods. That’s all for Spring RequestMapping Example, I hope it will help you in understanding this annotation and it’s various features. You should download the sample project from below link and try different scenarios to explore it further.