spring3 的restful API RequestMapping介绍
原文链接:http://www.javaarch.net/jiagoushi/694.htm
spring3 的restful API RequestMapping介绍 在spring mvc中 @RequestMapping是把web请求映射到controller的方法上。 1.RequestMapping Basic Example 将http请求映射到controller方法的最直接方式 1.1 @RequestMapping by Path @RequestMapping(value = "/foos") @ResponseBody public String getFoosBySimplePath() { return "Get some Foos"; } 可以通过下面的方式测试: curl -i http://localhost:8080/springmvc/foos 1.2 @RequestMapping – the HTTP Method,我们可以加上http方法的限制 @RequestMapping(value = "/foos", method = RequestMethod.POST) @ResponseBody public String postFoos() { return "Post some Foos"; } 可以通过curl i -X POST http://localhost:8080/springmvc/foos测试。 2.RequestMapping 和http header 2.1 @RequestMapping with the headers attribute 当request的header包含某个key value值时 @RequestMapping(value = "/foos", headers = "key=val") @ResponseBody public String getFoosWithHeader() { return "Get some Foos with Header"; } header多个字段满足条件时 @RequestMapping(value = "/foos", headers = { "key1=val1", "key2=val2" }) @ResponseBody public String getFoosWithHeaders() { return "Get some Foos with Header"; } 通过curl -i -H "key:val" http://localhost:8080/springmvc/foos 测试。 2.2 @RequestMapping 和Accept头 @RequestMapping(value = "/foos", method = RequestMethod.GET, headers = "Accept=application/json") @ResponseBody public String getFoosAsJsonFromBrowser() { return "Get some Foos with Header Old"; } 支持accept头为json的请求,通过curl -H "Accept:application/json,text/html" http://localhost:8080/springmvc/foos测试 在spring3.1中@RequestMapping注解有produces和 consumes 两个属性来代替accept头 @RequestMapping(value = "/foos", method = RequestMethod.GET, produces = "application/json") @ResponseBody public String getFoosAsJsonFromREST() { return "Get some Foos with Header New"; } 同样可以通过curl -H "Accept:application/json" http://localhost:8080/springmvc/foos测试 produces可以支持多个 @RequestMapping(value = "/foos", produces = { "application/json", "application/xml" }) 当前不能有两个方法同时映射到同一个请求,要不然会出现下面这个异常 Caused by: java.lang.IllegalStateException: Ambiguous mapping found. Cannot map 'fooController' bean method public java.lang.String org.baeldung.spring.web.controller.FooController.getFoosAsJsonFromREST() to {[/foos],methods=[GET],params=[],headers=[],consumes=[],produces=[application/json],custom=[]}: There is already 'fooController' bean method public java.lang.String org.baeldung.spring.web.controller.FooController.getFoosAsJsonFromBrowser() mapped. 3.RequestMapping with Path Variables 3.1我们可以把@PathVariable把url映射到controller方法 单个@PathVariable参数映射 @RequestMapping(value = "/foos/{id}") @ResponseBody public String getFoosBySimplePathWithPathVariable(@PathVariable("id") long id) { return "Get a specific Foo with id=" + id; } 通过curl http://localhost:8080/springmvc/foos/1试试 如果参数名跟url参数名一样,可以省略为 @RequestMapping(value = "/foos/{id}") @ResponseBody public String getFoosBySimplePathWithPathVariable(@PathVariable String id) { return "Get a specific Foo with id=" + id; } 3.2 多个@PathVariable @RequestMapping(value = "/foos/{fooid}/bar/{barid}") @ResponseBody public String getFoosBySimplePathWithPathVariables(@PathVariable long fooid, @PathVariable long barid) { return "Get a specific Bar with id=" + barid + " from a Foo with id=" + fooid; } 通过curl http://localhost:8080/springmvc/foos/1/bar/2测试。 3.3支持正则的@PathVariable @RequestMapping(value = "/bars/{numericId:[\\d]+}") @ResponseBody public String getBarsBySimplePathWithPathVariable(@PathVariable final long numericId) { return "Get a specific Bar with id=" + numericId; } 这个url匹配:http://localhost:8080/springmvc/bars/1 不过这个不匹配:http://localhost:8080/springmvc/bars/abc 4.RequestMapping with Request Parameters 我们可以使用 @RequestParam注解把请求参数提取出来 比如url:http://localhost:8080/springmvc/bars?id=100 @RequestMapping(value = "/bars") @ResponseBody public String getBarBySimplePathWithRequestParam(@RequestParam("id") long id) { return "Get a specific Bar with id=" + id; } 我们可以通过RequestMapping定义参数列表 @RequestMapping(value = "/bars", params = "id") @ResponseBody public String getBarBySimplePathWithExplicitRequestParam(@RequestParam("id") long id) { return "Get a specific Bar with id=" + id; } 和 @RequestMapping(value = "/bars", params = { "id", "second" }) @ResponseBody public String getBarBySimplePathWithExplicitRequestParams(@RequestParam("id") long id) { return "Narrow Get a specific Bar with id=" + id; } 比如http://localhost:8080/springmvc/bars?id=100&second=something会匹配到最佳匹配的方法上,这里会映射到下面这个。 5.RequestMapping Corner Cases 5.1 @RequestMapping多个路径映射到同一个controller的同一个方法 @RequestMapping(value = { "/advanced/bars", "/advanced/foos" }) @ResponseBody public String getFoosOrBarsByPath() { return "Advanced - Get some Foos or Bars"; } 下面这两个url会匹配到同一个方法 curl -i http://localhost:8080/springmvc/advanced/foos curl -i http://localhost:8080/springmvc/advanced/bars 5.2@RequestMapping 多个http方法 映射到同一个controller的同一个方法 @RequestMapping(value = "/foos/multiple", method = { RequestMethod.PUT, RequestMethod.POST }) @ResponseBody public String putAndPostFoos() { return "Advanced - PUT and POST within single method"; } 下面这两个url都会匹配到上面这个方法 curl -i -X POST http://localhost:8080/springmvc/foos/multiple curl -i -X PUT http://localhost:8080/springmvc/foos/multiple 5.3@RequestMapping 匹配所有方法 @RequestMapping(value = "*") @ResponseBody public String getFallback() { return "Fallback for GET Requests"; } 匹配所有方法 @RequestMapping(value = "*", method = { RequestMethod.GET, RequestMethod.POST ... }) @ResponseBody public String allFallback() { return "Fallback for All Requests"; } 6.Spring Configuration controller的annotation @Controller public class FooController { ... } spring3.1 @Configuration @EnableWebMvc @ComponentScan({ "org.baeldung.spring.web.controller" }) public class MvcConfig { // } 可以从这里看到所有的示例https://github.com/eugenp/tutorials/tree/master/springmvc