Spring RequestMapping for controllers that produce and consume JSON

Question

With multiple Spring controllers that consume and produce application json  my code is littered with long annotations like        RequestMapping value     foo   method   RequestMethod POST              consumes   MediaType APPLICATION JSON VALUE              produces   MediaType APPLICATION JSON VALUE    Is there a way to produce a  composite inherited aggregated  annotation with default values for consumes and produces  such that I could instead write something like        JSONRequestMapping value     foo   method   RequestMethod POST    How do we define something like  JSONRequestMapping above   Notice the value and method passed in just like in  RequestMapping  also good to be able to pass in consumes or produces if the default isn t suitable   I need to control what I m returning   I want the produces consumes annotation-methods so that I get the appropriate Content-Type headers

User · Answer

There are 2 annotations in Spring   RequestBody and  ResponseBody  These annotations consumes  respectively produces JSONs  Some more info here

User · Answer

As of Spring 4 2 x  you can create custom mapping annotations  using  RequestMapping as a meta-annotation  So      Is there a way to produce a  composite inherited aggregated    annotation with default values for consumes and produces  such that I   could instead write something like    JSONRequestMapping value     foo   method   RequestMethod POST     Yes  there is such a way  You can create a meta annotation like following    Target  ElementType METHOD  ElementType TYPE    Retention RetentionPolicy RUNTIME   RequestMapping consumes    application json   produces    application json   public  interface JsonRequestMapping        AliasFor annotation   RequestMapping class  attribute    value       String   value   default           AliasFor annotation   RequestMapping class  attribute    method       RequestMethod   method   default           AliasFor annotation   RequestMapping class  attribute    params       String   params   default           AliasFor annotation   RequestMapping class  attribute    headers       String   headers   default           AliasFor annotation   RequestMapping class  attribute    consumes       String   consumes   default           AliasFor annotation   RequestMapping class  attribute    produces       String   produces   default         Then you can use the default settings or even override them as you want    JsonRequestMapping method   POST  public String defaultSettings         return  Default settings       JsonRequestMapping value     override   method   PUT  produces    text plain   public String overrideSome  RequestBody String json        return json      You can read more about AliasFor in spring s javadoc and github wiki

User · Answer

The simple answer to your question is that there is no Annotation-Inheritance in Java  However  there is a way to use the Spring annotations in a way that I think will help solve your problem    RequestMapping is supported at both the type level and at the method level   When you put  RequestMapping at the type level  most of the attributes are  inherited  for each method in that class  This is mentioned in the Spring reference documentation  Look at the api docs for details on how each attribute is handled when adding  RequestMapping to a type  I ve summarized this for each attribute below    name  Value at Type level is concatenated with value at method level using     as a separator  value  Value at Type level is inherited by method  path  Value at Type level is inherited by method  method  Value at Type level is inherited by method  params  Value at Type level is inherited by method  headers  Value at Type level is inherited by method  consumes  Value at Type level is overridden by method  produces  Value at Type level is overridden by method    Here is a brief example Controller that showcases how you could use this   package com example   import org springframework http MediaType  import org springframework web bind annotation      RestController  RequestMapping path                 consumes   MediaType APPLICATION JSON VALUE           produces   MediaType APPLICATION JSON VALUE           method    RequestMethod GET  RequestMethod POST   public class JsonProducingEndpoint        private FooService fooService        RequestMapping path     foo   method   RequestMethod POST      public String postAFoo  RequestBody ThisIsAFoo theFoo            fooService saveTheFoo theFoo           return  http   myservice com foo 1               RequestMapping path     foo  id    method   RequestMethod GET      public ThisIsAFoo getAFoo  PathVariable String id            ThisIsAFoo foo   fooService getAFoo id           return foo              RequestMapping path     foo  id    produces   MediaType APPLICATION XML VALUE  method   RequestMethod GET      public ThisIsAFooXML getAFooXml  PathVariable String id            ThisIsAFooXML foo   fooService getAFoo id           return foo

User · Answer

You can use the  RestController instead of  Controller annotation

User · Answer

You shouldn t need to configure the consumes or produces attribute at all   Spring will automatically serve JSON based on the following factors    The accepts header of the request is application json  ResponseBody annotated method Jackson library on classpath   You should also follow Wim s suggestion and define your controller with the  RestController annotation   This will save you from annotating each request method with  ResponseBody  Another benefit of this approach would be if a client wants XML instead of JSON  they would get it   They would just need to specify xml in the accepts header

[java] Spring RequestMapping for controllers that produce and consume JSON

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