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

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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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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.*;

import org.apache.juneau.http.response.*;

/**
 * Identifies a method that is called immediately after the HttpServlet.service(HttpServletRequest, HttpServletResponse)
 * method is called.
 *
 * 
 * Note that you only have access to the raw request and response objects at this point.
 *
 * 

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

 * 	Servlet request/response objects:
 * 		
 * 			{@link HttpServletRequest}
 * 			
{@link HttpServletResponse}
 * 		
 * 
 *
 * Example:
 * 
 * 	@Rest(...)
 * 	public class MyResource extends BasicRestServlet {
 *
 * 		// Add a request attribute to all incoming requests.
 * 		@RestStartCall
 * 		public void onStartCall(HttpServletRequest req) {
 * 			req.setAttribute("foobar", new FooBar());
 * 		}
 * 	}
 * 
 *
 * 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 start-call methods can be defined on a class.
 * 		
Start call methods on parent classes are invoked before start-call methods on child classes.
 * 		
The order of start-call method invocations within a class is alphabetical, then by parameter count, then by parameter types.
 * 	

 * 		The method can throw any exception.
 * 		
{@link BasicHttpException BasicHttpExceptions} can be thrown to cause a particular HTTP error status code.
 * 		
All other exceptions cause an HTTP 500 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(RestStartCallAnnotation.Array.class)
public @interface RestStartCall {

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

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