# Lifespan Events { #lifespan-events }

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

     * does your mojo requires a project to be executed?
     * @return requires a project
     */
    boolean projectRequired() default true;

    /**
     * if the Mojo uses the Maven project and its subprojects.
     * @return uses the Maven project and its subprojects
     */
    boolean aggregator() default false;

    /**
     * does this Mojo need to be online to be executed?
     * @return need to be online
     */

     */
    void setInitParameterMap(Map<String, Object> params);

    /**
     * Executes a request and returns the response data.
     *
     * @param data the request data to be executed
     * @return the response data from the executed request
     */
    ResponseData execute(RequestData data);

    /**
     * Closes the crawler client and releases any resources associated with it.

 *   It is similar to a Promise in JavaScript.
 *   It allows you to register callbacks that will be executed when the computation is complete,
 *   either successfully (resolve) or with an error (reject).
 * </p>
 *
 * <p>
 *   The Deferred class has a Promise inner class that allows you to register callbacks
 *   to be executed when the computation is complete.

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

/// tip

Some editors check for unused function parameters, and show them as errors.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

		l.Logger.ErrorContext(ctx, "SQL executed", slog.Attr{
			Key:   "trace",
			Value: slog.GroupValue(fields...),
		})

	case l.SlowThreshold != 0 && elapsed > l.SlowThreshold:
		l.Logger.WarnContext(ctx, "SQL executed", slog.Attr{
			Key:   "trace",
			Value: slog.GroupValue(fields...),
		})

	case l.LogLevel >= Info:
		l.Logger.InfoContext(ctx, "SQL executed", slog.Attr{
			Key:   "trace",

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Only the code prior to and including the `yield` statement is executed before creating a response:

{* ../../docs_src/dependencies/tutorial007.py hl[2:4] *}

The yielded value is what is injected into *path operations* and other dependencies:

{* ../../docs_src/dependencies/tutorial007.py hl[4] *}

The code following the `yield` statement is executed after creating the response but before sending it: