org.apache.juneau.rest.annotation.RestEndCall 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 jakarta.servlet.http.*;

/**
 * Identifies a method that gets called right before we exit the servlet service method.
 *
 * 
 * At this point, the output has been written and flushed.
 *
 * 

 * The list of valid parameter types are as follows:
 * 

 * 	Servlet request/response objects:
 * 		
 * 			{@link HttpServletRequest}
 * 			
{@link HttpServletResponse}
 * 		
 * 
 *
 * 
 * The following attributes are set on the {@link HttpServletRequest} object that can be useful for logging purposes:
 * 

 * 	"Exception" - Any exceptions thrown during the request.
 * 	
"ExecTime" - Execution time of the request.
 * 
 *
 * Example:
 * 
 * 	@Rest(...)
 * 	public class MyResource extends BasicRestServlet {
 *
 * 		// Log the time it took to execute the request.
 * 		@RestEndCall
 * 		public void onEndCall(HttpServletRequest req, Logger logger) {
 * 			Exception exception = (Exception)req.getAttribute("Exception");
 * 			Long execTime = (Long)req.getAttribute("ExecTime");
 * 			if (exception != null)
 * 				logger.warn(exception, "Request failed in {0}ms.", execTime);
 * 			else
 * 				logger.fine("Request finished in {0}ms.", execTime);
 * 		}
 * 	}
 * 
 *
 * Notes:

 * 	
 * 		The method should return void although if it does return any value, the value will be ignored.
 * 	

 * 		The method should be public although other visibilities are valid if the security manager allows it.
 * 	

 * 		Static methods can be used.
 * 	

 * 		Multiple END_CALL methods can be defined on a class.
 * 		
END_CALL methods on parent classes are invoked before END_CALL methods on child classes.
 * 		
The order of END_CALL method invocations within a class is alphabetical, then by parameter count, then by parameter types.
 * 	

 * 		The method can throw any exception, although at this point it is too late to set an HTTP error status code.
 * 	

 * 		Note that if you override a parent method, you probably need to call super.parentMethod(...).
 * 		
The method is still considered part of the parent class for ordering purposes even though it's
 * 		overridden by the child class.
 * 
 *
 * See Also:

 * 	Lifecycle Hooks
 * 
 */
@Target({METHOD,TYPE})
@Retention(RUNTIME)
@Inherited
@Repeatable(RestEndCallAnnotation.Array.class)
public @interface RestEndCall {

	/**
	 * Dynamically apply this annotation to the specified methods.
	 *
	 * See Also:

	 * 	Dynamically Applied Annotations
	 * 
	 *
	 * @return The annotation value.
	 */
	String[] on() default {};
}