#930 Register captcha: avoid circular dependency by handling limbo message in captcha command

- Set limbo message in captcha command (as is done for login captcha)
- Add clarifying comments to captcha command
- Remove classes handling circular dependencies

src/main/java/fr/xephi/authme/initialization/circulardependency/CircularDependencyInitializer.java

@@ -1,69 +0,0 @@
-package fr.xephi.authme.initialization.circulardependency;
-
-import ch.jalu.injector.Injector;
-import ch.jalu.injector.utils.ReflectionUtils;
-
-import javax.inject.Inject;
-import java.lang.reflect.Method;
-import java.lang.reflect.Modifier;
-
-/**
- * Fix for circular dependencies: after initialization this class can be called
- * to inject dependencies via {@link InjectAfterInitialization} methods.
- */
-public class CircularDependencyInitializer {
-
-    @Inject
-    private Injector injector;
-
-    CircularDependencyInitializer() {
-    }
-
-    /**
-     * Processes all known {@link HasCircularDependency} classes, invoking all methods
-     * annotated with {@link InjectAfterInitialization}.
-     */
-    public void initializeCircularDependencies() {
-        for (HasCircularDependency hasCircularDependency : injector.retrieveAllOfType(HasCircularDependency.class)) {
-            processClass(hasCircularDependency);
-        }
-    }
-
-    private void processClass(HasCircularDependency object) {
-        for (Method method : object.getClass().getDeclaredMethods()) {
-            if (method.isAnnotationPresent(InjectAfterInitialization.class)) {
-                Object resolvedObject = resolveParameterForMethodOrThrow(method);
-                ReflectionUtils.invokeMethod(method, object, resolvedObject);
-            }
-        }
-    }
-
-    /**
-     * Validates that the given method is a valid {@link InjectAfterInitialization} method
-     * and resolves the parameter it should be passed (assumes a singleton of the given type is registered
-     * in the injector). Throws an exception if the parameter type is not a registered singleton.
-     *
-     * @param method the method to process
-     * @return object to pass to the initializer method
-     */
-    private Object resolveParameterForMethodOrThrow(Method method) {
-        if (method.getParameterCount() != 1) {
-            throw new IllegalStateException("Method " + method.getDeclaringClass() + "#" + method.getName()
-                + " should have one parameter only");
-        } else if (!Modifier.isPublic(method.getModifiers())) {
-            throw new IllegalStateException("Method " + method.getDeclaringClass() + "#" + method.getName()
-                + " should be public");
-        } else if (method.getReturnType() != void.class) {
-            throw new IllegalStateException("Method " + method.getDeclaringClass() + "#" + method.getName()
-                + " must return void");
-        }
-
-        final Class<?> requiredType = method.getParameterTypes()[0];
-        final Object resolvedObject = injector.getIfAvailable(requiredType);
-        if (resolvedObject == null) {
-            throw new IllegalStateException("Failed to get parameter of type '" + requiredType
-                + "' for @InjectAfterInitialization method " + method.getDeclaringClass() + "#" + method.getName());
-        }
-        return resolvedObject;
-    }
-}

src/main/java/fr/xephi/authme/initialization/circulardependency/HasCircularDependency.java

@@ -1,7 +0,0 @@
-package fr.xephi.authme.initialization.circulardependency;
-
-/**
- * Marker interface for classes with {@link HasCircularDependency} methods.
- */
-public interface HasCircularDependency {
-}

src/main/java/fr/xephi/authme/initialization/circulardependency/InjectAfterInitialization.java

@@ -1,21 +0,0 @@
-package fr.xephi.authme.initialization.circulardependency;
-
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * Marks a method that should be invoked once injection has taken place.
- * This is a fix for circular dependencies.
- * <p>
- * Methods with this annotation must have exactly one parameter whose type is a singleton
- * registered in the injector. Classes with such methods must implement the {@link HasCircularDependency}
- * marker interface.
- *
- * @see CircularDependencyInitializer
- */
-@Retention(RetentionPolicy.RUNTIME)
-@Target(ElementType.METHOD)
-public @interface InjectAfterInitialization {
-}