io.neba.spring.api

Annotation Type ResourceParam

@Retention(value=RUNTIME)
 @Target(value={PARAMETER,ANNOTATION_TYPE})
 @Documented
public @interface ResourceParam

Marks a parameter of a Spring @RequestMapping method as containing a resource path. This path is automatically resolved by NEBA using the request's resource resolver. If the annotated parameter's type is not assignable from Resource, the resolved resource is adapted to the target type. Otherwise, the resolved resource is provided.

Example:

  @Controller
  @RequestMapping(produces = "text/plain")
  public class MyController {
      @RequestMapping("/echoTitle")
      @ResponseBody
      public String echoTitle(@ResourceParam Page page) {
          return page.getTitle();
      }
  }
  

In the above example, a request parameter "page" is expected. The parameter value is regarded as a resource path and the corresponding resource is resolved. The resolved resource is subsequently adapted to "Page":

GET /bin/mvc.do/echoTitle?path=/content/site/en: "English page title".

One may also append a segment to the path prior to resolution, for instance to target a sub resource of the provided path, like so:

      public String echoTitle(@ResourceParam(append = "jcr:content") PageContent content) {
          return page.getTitle();
      }
  

The append path is also applied to the default value, if provided.

By default, @ResourceParam parameters are required. If the parameter is missing, cannot be resolved to an existing resource or cannot be adapted to the required target type, an exception is thrown. Accordingly, the parameter provided to the controller method is guaranteed not to be null if it is required. Consequently, the parameter may be null if either the parameter value is missing, cannot be resolved to an existing resource or if the resolved resource cannot be adapted to the required target type when the parameter is not required. If a default value is provided, the parameter is always optional, regardless whether it is required. If the default value cannot be resolved, the parameter provided to the method is null.

Author:

Olaf Otto

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	append Append this path segment to the provided path prior to resource resolution.
String	defaultValue
boolean	required
String	value The name of the request parameter.

Element Detail

value

public abstract String value

The name of the request parameter. Defaults to the name of the annotated parameter.

Default:

""

required

public abstract boolean required

Returns:

when true, the resolved parameter is guaranteed not to be null.

Default:

true

defaultValue

public abstract String defaultValue

Returns:

if not null or empty, this default value is used in case no value is provided for this request parameter. Providing a default value implies required() = false.

Default:

""

append

public abstract String append

Append this path segment to the provided path prior to resource resolution.

Default:

""