{"id":3175,"date":"2019-03-08T05:35:53","date_gmt":"2019-03-08T05:35:53","guid":{"rendered":"http:\/\/codethataint.com\/blog\/?p=3175"},"modified":"2019-03-16T17:36:24","modified_gmt":"2019-03-16T17:36:24","slug":"spring-rest-annotations","status":"publish","type":"post","link":"https:\/\/codethataint.com\/blog\/spring-rest-annotations\/","title":{"rendered":"Spring REST Annotations"},"content":{"rendered":"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Annotation<\/th>\nUsage<\/th>\n<\/tr>\n<\/thead>\n
@RequestMapping<\/td>\n\n
\r\n@RequestMapping(value = "\/{name}", \r\n                method = RequestMethod.GET, \r\n                consumes="application\/json"\r\n                produces ="application\/json",\r\n                headers={"name=pankaj", "id=1"})\r\n<\/pre>\n<\/td>\n<\/tr>\n
path (or) (or) name (or) and value: which URL the method is mapped to
\nmethod: compatible HTTP methods
\nparams: filters requests based on presence, absence, or value of HTTP parameters
\nheaders: filters requests based on presence, absence, or value of HTTP headers
\nconsumes: which media types the method can consume in the HTTP request body
\nproduces: which media types the method can produce in the HTTP response body<\/td>\n<\/tr>\n
@RequestBody<\/td>\n\n
\r\n@RequestMapping(method = RequestMethod.POST)\r\n@ResponseBody\r\npublic HttpStatus something(@RequestBody MyModel myModel) \r\n{\r\n    return HttpStatus.OK;\r\n}\r\n<\/pre>\n<\/td>\n<\/tr>\n
with @RequestBody, Spring will bind the incoming HTTP request body(for the URL mentioned in @RequestMapping for that method) to that parameter. While doing that, Spring will [behind the scenes] use HTTP Message converters to convert the HTTP request body into domain object [deserialize request body to domain object], based on Accept header present in request.<\/td>\n<\/tr>\n
@ResponseBody<\/td>\n\n
\r\n@RequestMapping(value = "\/user\/all", method = RequestMethod.GET)\r\npublic @ResponseBody List<User> listAllUsers() {\r\n    return userService.findAllUsers();\r\n}\r\n<\/pre>\n<\/tr>\n
with @ResponseBody, Spring will bind the return value to outgoing HTTP response body. While doing that, Spring will [behind the scenes] use HTTP Message converters to convert the return value to HTTP response body\u00a0[serialize the object to response body], based on\u00a0Content-Type\u00a0present in request HTTP header<\/td>\n<\/tr>\n
@RequestParam<\/td>\n\n
\r\nhttp:\/\/localhost:8080\/springmvc\/hello\/101?param1=10¶m2=20\r\n\r\npublic String getDetails(\r\n    @RequestParam(value="param1", required=true) String param1,\r\n        @RequestParam(value="param2", required=false) String param2){\r\n...\r\n}\r\n<\/pre>\n<\/td>\n<\/tr>\n
@RequestParam is to obtain an parameter from the URI as well.@RequestParam annotation used for accessing the query parameter values from the request
\ndefaultValue \u2013 This is the default value as a fallback mechanism if request is not having the value or it is empty.
\nname \u2013 Name of the parameter to bind
\nrequired \u2013 Whether the parameter is mandatory or not. If it is true, failing to send that parameter will fail.
\nvalue \u2013 This is an alias for the name attribute<\/td>\n<\/tr>\n

”<\/p>\n

@PathVariable<\/td>\n\n
\r\n'http:\/\/localhost:8080\/springmvc\/hello\/101?param1=10&param2=20\r\n\r\n@RequestMapping("\/hello\/{id}")    public String getDetails(@PathVariable(value="id") String id,\r\n    @RequestParam(value="param1", required=true) String param1,\r\n    @RequestParam(value="param2", required=false) String param2){\r\n.......\r\n}\r\n\r\n@GetMapping("\/user\/{firstName}\/{lastName}")\r\n   @ResponseBody\r\n   public String handler(@MatrixVariable("firstName") String firstName,\r\n         @MatrixVariable("lastName") String lastName\r\n         ) {\r\n\r\n      return "<br>Matxrix variable <br> "\r\n            + "firstName =" + firstName +"<br>"\r\n            + "lastName =" + lastName;\r\n   }\r\n<\/pre>\n<\/td>\n<\/tr>\n
@PathVariable is to obtain some placeholder from the URI
\n@MatrixVariable – a name-value pair within a path segment is referred as matrix variable. Matrix variables can appear in any path segment, each variable separated with a semicolon (;) and multiple values are separated by comma (,)
\ni.e.
\nhttp:\/\/www.example.com\/employee\/Mike;salary=45000;dept=HR
\nhttp:\/\/www.example.com\/car\/Audi;color=RED,BLACK,WHITE<\/p>\n<\/td>\n<\/tr>\n
@RequestHeader<\/td>\n\n
\r\n@Controller\r\npublic class HelloController {\r\n @RequestMapping(value = "\/hello.htm")\r\n public String hello(\r\n   @RequestHeader(value="Accept") String accept,\r\n   @RequestHeader(value="Accept-Language") String acceptLanguage,\r\n   @RequestHeader(value="User-Agent", defaultValue="foo") String userAgent,\r\n   HttpServletResponse response) {\r\n\r\n  System.out.println("accept: " + accept);\r\n  System.out.println("acceptLanguage: " + acceptLanguage);\r\n  System.out.println("userAgent: " + userAgent);\r\n  \r\n  return null;\r\n }\r\n}\r\n<\/pre>\n<\/td>\n<\/tr>\n
Reading http requestheader is written in HelloController
\nThe advantage of using Spring @RequestHeader is that it will automatically throw an exception like HTTP Status 400 – Missing request header ‘X’ for method parameter of type, if the header is NOT sent in the input request (by setting required=true)<\/p>\n

@RequestHeader for facilitating use to get the header details easily in our controller class<\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Annotation Usage @RequestMapping @RequestMapping(value = "\/{name}", method = RequestMethod.GET, consumes="application\/json" produces ="application\/json", headers={"name=pankaj", "id=1"}) path (or) (or) name (or) and value: which URL the method is mapped to method: compatible HTTP methods params: filters requests based on presence, absence, or value of HTTP parameters headers: filters requests based on presence, absence, or value of HTTP… Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[264],"tags":[],"class_list":["post-3175","post","type-post","status-publish","format-standard","hentry","category-rest"],"_links":{"self":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/3175","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/comments?post=3175"}],"version-history":[{"count":9,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/3175\/revisions"}],"predecessor-version":[{"id":3227,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/3175\/revisions\/3227"}],"wp:attachment":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/media?parent=3175"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/categories?post=3175"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/tags?post=3175"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}