com.google.inject.Guice Maven / Gradle / Ivy

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package com.google.inject;

import com.google.inject.internal.InternalInjectorCreator;

import java.util.Arrays;

/**
 * The entry point to the Guice framework. Creates {@link Injector}s from
 * {@link Module}s.
 *
 * Guice supports a model of development that draws clear boundaries between
 * APIs, Implementations of these APIs, Modules which configure these
 * implementations, and finally Applications which consist of a collection of
 * Modules. It is the Application, which typically defines your {@code main()}
 * method, that bootstraps the Guice Injector using the {@code Guice} class, as
 * in this example:
 * 
 *     public class FooApplication {
 *       public static void main(String[] args) {
 *         Injector injector = Guice.createInjector(
 *             new ModuleA(),
 *             new ModuleB(),
 *             . . .
 *             new FooApplicationFlagsModule(args)
 *         );
 *
 *         // Now just bootstrap the application and you're done
 *         FooStarter starter = injector.getInstance(FooStarter.class);
 *         starter.runApplication();
 *       }
 *     }
 * 
 */
public final class Guice {

    private Guice() {
    }

    /**
     * Creates an injector for the given set of modules. This is equivalent to
     * calling {@link #createInjector(Stage, Module...)} with Stage.DEVELOPMENT.
     *
     * @throws CreationException if one or more errors occur during injector
     *                           construction
     */
    public static Injector createInjector(Module... modules) {
        return createInjector(Arrays.asList(modules));
    }

    /**
     * Creates an injector for the given set of modules. This is equivalent to
     * calling {@link #createInjector(Stage, Iterable)} with Stage.DEVELOPMENT.
     *
     * @throws CreationException if one or more errors occur during injector
     *                           creation
     */
    public static Injector createInjector(Iterable modules) {
        return createInjector(Stage.DEVELOPMENT, modules);
    }

    /**
     * Creates an injector for the given set of modules, in a given development
     * stage.
     *
     * @throws CreationException if one or more errors occur during injector
     *                           creation.
     */
    public static Injector createInjector(Stage stage, Module... modules) {
        return createInjector(stage, Arrays.asList(modules));
    }

    /**
     * Creates an injector for the given set of modules, in a given development
     * stage.
     *
     * @throws CreationException if one or more errors occur during injector
     *                           construction
     */
    public static Injector createInjector(Stage stage, Iterable modules) {
        return new InternalInjectorCreator().stage(stage).addModules(modules).build();
    }
}