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.

Answer 1

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.