org.apache.juneau.rest.annotation.Attr Maven / Gradle / Ivy

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package org.apache.juneau.rest.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.*;

import org.apache.juneau.httppart.*;
import org.apache.juneau.oapi.*;

/**
 * REST request attribute annotation.
 *
 * 
 * Identifies a POJO retrieved from the request attributes map.
 *
 * Annotation that can be applied to a parameter of a @RestOp-annotated method to identify it as a value
 * retrieved from the request attributes.
 *
 * 
Example:
 * 
 * 	@RestGet
 * 	public Person getPerson(@Attr("ETag") UUID etag) {...}
 * 
 *
 * 
 * This is functionally equivalent to the following code...
 * 

 * 	@RestPost
 * 	public void postPerson(RestRequest req, RestResponse res) {
 * 		UUID etag = req.getAttributes().get(UUID.class, "ETag");
 * 		...
 * 	}
 * 
  *
 * See Also:

 * 	Java Method Parameters

 * 
 */
@Target({PARAMETER,TYPE})
@Retention(RUNTIME)
@Inherited
public @interface Attr {

	/**
	 * Specifies the {@link HttpPartParser} class used for parsing strings to values.
	 *
	 * 
	 * Overrides for this part the part parser defined on the REST resource which by default is {@link OpenApiParser}.
	 *
	 * @return The annotation value.
	 */
	Class parser() default HttpPartParser.Void.class;

	//=================================================================================================================
	// Attributes common to all Swagger Parameter objects
	//=================================================================================================================

	/**
	 * Request attribute name.
	 *
	 * 

	 * The value should be either a valid attribute name, or "*" to represent multiple name/value pairs
	 *
	 * 

	 * A blank value (the default) has the following behavior:
	 * 

	 * 	
	 * 		If the data type is NameValuePairs, Map, or a bean,
	 * 		then it's the equivalent to "*" which will cause the value to be serialized as name/value pairs.
	 *
	 * 		Examples:
	 * 		
	 * 	@RestPost("/addPet")
	 * 	public void addPet(@Attr JsonMap allAttributes) {...}
	 * 		
	 * 	
	 * 
	 *
	 * @return The annotation value.
	 */
	String name() default "";

	/**
	 * A synonym for {@link #name()}.
	 *
	 * 
	 * Allows you to use shortened notation if you're only specifying the name.
	 *
	 * 

	 * The following are completely equivalent ways of defining a header entry:
	 * 

	 * 	public Order placeOrder(@Attr(name="api_key") String apiKey) {...}
	 * 
	 * 
	 * 	public Order placeOrder(@Attr("api_key") String apiKey) {...}
	 * 
	 *
	 * @return The annotation value.
	 */
	String value() default "";
}