org.apache.juneau.rest.arg.RestOpArg Maven / Gradle / Ivy

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package org.apache.juneau.rest.arg;

import org.apache.juneau.rest.*;
import org.apache.juneau.rest.annotation.*;

/**
 * REST java method parameter resolver.
 *
 * 
 * Used to resolve parameter values when invoking {@link RestOp}-annotated methods.
 *
 * 
Example:
 * 
 * 	// A simple parameter resolver that resolves TimeZone parameters.
 * 	public class TimeZoneArg implements RestOpArg {
 *
 * 		// Implementers must provide a static creator method that returns a RestParam if it's
 * 		// applicable to the specified parameter.
 * 		public static TimeZoneArg create(ParamInfo paramInfo) {
 * 			if (paramInfo.isType(TimeZone.class))
 * 				return new TimeZoneArg();
 * 			return null;
 * 		}
 *
 * 		protected TimeZoneArg() {}
 *
 * 		@Override
 * 		public Object resolve(RestOpSession opSession) throws Exception {
 * 			return opSession.getRequest().getHeaders().getTimeZone();
 * 		}
 * 	}
 * 
 *
 * See Also:

 * 	{@link org.apache.juneau.rest.RestContext.Builder#restOpArgs(Class...)}
 * 	
@RestOp-Annotated Methods
 * 
 */
public interface RestOpArg {

	/**
	 * Resolves the parameter object.
	 *
	 * @param opSession The rest call.
	 * @return The resolved object.
	 * @throws Exception Generic error occurred.
	 */
	Object resolve(RestOpSession opSession) throws Exception;
}