摘要：概述將某個(gè)請(qǐng)求映射到某個(gè)方法上這個(gè)注解可以加在某個(gè)或者某個(gè)方法上，如果加在上，則這個(gè)中的所有路由映射都將會(huì)加上這個(gè)前綴下面會(huì)有栗子，如果加在方法上，則沒(méi)有前綴下面也有栗子。

將某個(gè)http請(qǐng)求映射到某個(gè)方法上

這個(gè)注解可以加在某個(gè)Controller或者某個(gè)方法上，如果加在Controller上，則這個(gè)Controller中的所有路由映射都將會(huì)加上這個(gè)前綴（下面會(huì)有栗子），如果加在方法上，則沒(méi)有前綴（下面也有栗子）。

@RequestMapping有以下屬性

value: 請(qǐng)求的URL的路徑

path: 和value一樣

method: 請(qǐng)求的方法

consumes: 允許的媒體類型，也就是Content-Type

produces: 相應(yīng)的媒體類型，也就是Accept

params: 請(qǐng)求參數(shù)

headers: 請(qǐng)求頭部

首先編寫Controller，Controller頭部的@RestController將這個(gè)控制器標(biāo)注為Rest控制器：

package com.lyxxxx.rest.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

}

添加方法，并添加URL匹配：

    @RequestMapping()
    public Object hello() {
        return "hello";
    }
    

說(shuō)明：上面添加了一個(gè)方法，名為hello，沒(méi)有給定任何的屬性，則默認(rèn)匹配所有URL，方法為GET，所以我們可以直接使用GET方式來(lái)訪問(wèn)該路由
$ curl 127.0.0.1:8080
hello
$ curl 127.0.0.1:8080/user
hello
$ curl 127.0.0.1:8080/user/1
hello

精確匹配

@RequestMapping(value = "/hello2")
public Object hello2() {
    return "hello2";
}

說(shuō)明：上面將value設(shè)置為hello2，所以訪問(wèn)hello2將會(huì)執(zhí)行hello2方法
$ curl 127.0.0.1:8080/hello2
hello2

字符模糊匹配

@RequestMapping(value = "/hello3/*")
public Object hello3() {
    return "hello3";
}

說(shuō)明：上面將value設(shè)置為/hello3/*,*為匹配所有字符，也就是訪問(wèn)hello3下的所有URL都將匹配該防范
$ curl 127.0.0.1:8080/hello3/user
hello3
 curl 127.0.0.1:8080/hello3/1
hello3

單字符模糊匹配

$ curl 127.0.0.1:8080/hello4/1
hello4

說(shuō)明：上面將value設(shè)置為/hello4/?,?為匹配單個(gè)字符，匹配hello4/1，但是不會(huì)匹配hello4/11
$ curl 127.0.0.1:8080/hello4/1
hello4
$ curl 127.0.0.1:8080/hello4/12
{"timestamp":"2018-07-25T05:29:39.105+0000","status":404,"error":"Not Found","message":"No message available","path":"/hello4/12"}

全路徑模糊匹配

@RequestMapping(value = "/hello5/**")
public Object hello5() {
    return "hello5";
}

說(shuō)明：上面將value設(shè)置為/hello5/**,**為匹配所有路徑，所以hello5下面的所有路由都將匹配這個(gè)方法
$ curl 127.0.0.1:8080/hello5
hello5
$ curl 127.0.0.1:8080/hello5/user/1
hello5

多個(gè)路徑匹配

@RequestMapping(value = {"/hello6", "/hello6/1"})
public Object hello6() {
    return "hello6";
}

$ curl 127.0.0.1:8080/hello6
hello6
$ curl 127.0.0.1:8080/hello6/1
hello6F

讀取配置

// resources/application.properties

app.name=hello7

// com.lyxxxx.rest.controller.HelloController

@RequestMapping(value = "${app.name}")
public Object hello7() {
    return "hello7";
}

$ curl 127.0.0.1:8080/hello7
hello7

匹配請(qǐng)求中的method，寫在RequestMethod中的枚舉值：

GET

HEAD

POST

PUT

PATCH

DELETE

OPTIONS

TRACE

package com.lyxxxx.rest.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MethodController {
    @RequestMapping(path = "method/get", method = RequestMethod.GET)
    public Object get() {
        return "get";
    }

    @RequestMapping(path = "method/head", method = RequestMethod.HEAD)
    public Object head() {
        return "head";
    }

    @RequestMapping(path = "method/post", method = RequestMethod.POST)
    public Object post() {
        return "post";
    }

    @RequestMapping(path = "method/put", method = RequestMethod.PUT)
    public Object put() {
        return "put";
    }

    @RequestMapping(path = "method/patch", method = RequestMethod.PATCH)
    public Object patch() {
        return "patch";
    }

    @RequestMapping(path = "method/delete", method = RequestMethod.DELETE)
    public Object delete() {
        return "delete";
    }

    @RequestMapping(path = "method/options", method = RequestMethod.OPTIONS)
    public Object options() {
        return "options";
    }

    @RequestMapping(path = "method/trace", method = RequestMethod.TRACE)
    public Object trace() {
        return "trace";
    }


}

$ curl -X GET  127.0.0.1:8080/method/get
get
$ curl -X POST 127.0.0.1:8080/method/post
post
$ curl -X DELETE 127.0.0.1:8080/method/delete
delete
$ curl -X PUT 127.0.0.1:8080/method/put
put
...

除了可以匹配URL和method之外，還可以匹配params

package com.lyxxxx.rest.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ParamsController {
    @RequestMapping(path = "/params", params = "userId=1")
    public Object params() {
        return "params";
    }
}

$ curl 127.0.0.1:8080/params?userId=1
params

@RestController
public class HeaderController {
    @RequestMapping(path = "/headers", headers = "userId=1")
    public Object headers() {
        return "headers";
    }
}

$ curl 127.0.0.1:8080/headers
{"timestamp":"2018-08-01T06:11:40.037+0000","status":404,"error":"Not Found","message":"No message available","path":"/headers"}
$ curl 127.0.0.1:8080/headers -H "userId:1"
headers

@RestController
public class ConsumesController {

    @RequestMapping(value = "consumes",consumes = "application/json")
    public Object json() {
        return "consumes";
    }
}

$ curl 127.0.0.1:8080/consumes -H "Content-Type:application/json"
consumes
$ curl 127.0.0.1:8080/consumes -H "Content-Type:none"
{"timestamp":"2018-08-01T06:15:10.919+0000","status":415,"error":"Unsupported Media Type","message":"Invalid mime type "none": does not contain "/"","path":"/consumes"}

@RestController
public class ProducesController {
    @RequestMapping(value = "/produces", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public Object produces() {
        return "produces";
    }
}

$ curl 127.0.0.1:8080/produces 
produces
$ curl 127.0.0.1:8080/produces -H "Accept:text"
// 空

以上參考數(shù)據(jù)：《Spring Boot2精髓 從構(gòu)建小系統(tǒng)到架構(gòu)分部署大系統(tǒng)》