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CitymonstretCitymonstret
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feature(annotations) @ExceptionHandler methods (#538)
1 parent 4169901 commit e828c3a

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Lines changed: 371 additions & 1 deletion

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‎cloud-annotations/src/main/java/cloud/commandframework/annotations/AnnotationParser.java‎

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@@ -26,6 +26,8 @@
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import cloud.commandframework.Command;
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import cloud.commandframework.CommandComponent;
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import cloud.commandframework.CommandManager;
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import cloud.commandframework.annotations.exception.ExceptionHandler;
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import cloud.commandframework.annotations.exception.ExceptionHandlerFactory;
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import cloud.commandframework.annotations.injection.ParameterInjectorRegistry;
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import cloud.commandframework.annotations.injection.RawArgs;
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import cloud.commandframework.annotations.parsers.MethodArgumentParser;
@@ -107,6 +109,7 @@ public final class AnnotationParser<C> {
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private FlagAssembler flagAssembler;
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private CommandExtractor commandExtractor;
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private SuggestionProviderFactory<C> suggestionProviderFactory;
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private ExceptionHandlerFactory<C> exceptionHandlerFactory;
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/**
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* Construct a new annotation parser
@@ -170,6 +173,7 @@ public AnnotationParser(
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this.argumentAssembler = new ArgumentAssemblerImpl<>(this);
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this.commandExtractor = new CommandExtractorImpl(this);
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this.suggestionProviderFactory = SuggestionProviderFactory.defaultFactory();
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this.exceptionHandlerFactory = ExceptionHandlerFactory.defaultFactory();
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// TODO(City): Add mapper so that we can map this to rich descriptions easily.
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this.registerBuilderModifier(
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CommandDescription.class,
@@ -547,6 +551,28 @@ public void suggestionProviderFactory(final @NonNull SuggestionProviderFactory<C
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this.suggestionProviderFactory = suggestionProviderFactory;
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}
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/**
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* Returns the exception provider factory.
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*
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* @return the exception provider factory
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* @since 2.0.0
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*/
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@API(status = API.Status.STABLE, since = "2.0.0")
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public @NonNull ExceptionHandlerFactory<C> exceptionHandlerFactory() {
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return this.exceptionHandlerFactory;
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}
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/**
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* Sets the exception provider factory.
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*
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* @param exceptionHandlerFactory new exception provider factory
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* @since 2.0.0
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*/
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@API(status = API.Status.STABLE, since = "2.0.0")
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public void exceptionHandlerFactory(final @NonNull ExceptionHandlerFactory<C> exceptionHandlerFactory) {
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this.exceptionHandlerFactory = exceptionHandlerFactory;
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}
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/**
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* Parses all known {@link cloud.commandframework.annotations.processing.CommandContainer command containers}.
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*
@@ -610,6 +636,7 @@ public void suggestionProviderFactory(final @NonNull SuggestionProviderFactory<C
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public <T> @NonNull Collection<@NonNull Command<C>> parse(final @NonNull T instance) {
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this.parseSuggestions(instance);
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this.parseParsers(instance);
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this.parseExceptionHandlers(instance);
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final Collection<CommandDescriptor> commandDescriptors = this.commandExtractor.extractCommands(instance);
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final Collection<Command<C>> commands = this.construct(instance, commandDescriptors);
@@ -669,6 +696,28 @@ private <T> void parseSuggestions(final @NonNull T instance) {
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}
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}
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@SuppressWarnings("unchecked")
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private <T> void parseExceptionHandlers(final @NonNull T instance) {
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for (final Method method : instance.getClass().getMethods()) {
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final ExceptionHandler exceptionHandler = method.getAnnotation(ExceptionHandler.class);
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if (exceptionHandler == null) {
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continue;
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}
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if (!method.isAccessible()) {
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method.setAccessible(true);
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}
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try {
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this.manager.exceptionController().registerHandler(
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(Class<Throwable>) exceptionHandler.value(),
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this.exceptionHandlerFactory.createExceptionHandler(instance, method)
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);
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} catch (final Exception e) {
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throw new RuntimeException(e);
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}
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}
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}
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@SuppressWarnings("deprecation")
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private <T> void parseParsers(final @NonNull T instance) {
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for (final Method method : instance.getClass().getMethods()) {

‎cloud-annotations/src/main/java/cloud/commandframework/annotations/exception/ExceptionHandler.java‎

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//
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// MIT License
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//
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// Copyright (c) 2022 Alexander Söderberg & Contributors
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in all
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// copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18+
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19+
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20+
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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//
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package cloud.commandframework.annotations.exception;
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import cloud.commandframework.exceptions.handling.ExceptionContext;
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import java.lang.annotation.ElementType;
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import java.lang.annotation.Retention;
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import java.lang.annotation.RetentionPolicy;
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import java.lang.annotation.Target;
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import org.apiguardian.api.API;
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import org.checkerframework.checker.nullness.qual.NonNull;
33+
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/**
35+
* Annotation used to map methods to {@link cloud.commandframework.exceptions.handling.ExceptionHandler exception handlers}.
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* <p>
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* The method signature is not fixed, and the parameters can be any combination of: <ul>
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* <li>{@link cloud.commandframework.exceptions.handling.ExceptionContext}</li>
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* <li>{@link #value()}</li>
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* <li>{@link cloud.commandframework.context.CommandContext}</li>
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* <li>the command sender type</li>
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* <li>any type that can be injected using {@link cloud.commandframework.context.CommandContext#inject(Class)}</li>
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* </ul>
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* <p>
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* See {@link cloud.commandframework.exceptions.handling.ExceptionHandler#handle(ExceptionContext)} for information about
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* the exception handler behavior.
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*
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* @since 2.0.0
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*/
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@Retention(RetentionPolicy.RUNTIME)
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@Target(ElementType.METHOD)
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@API(status = API.Status.STABLE, since = "2.0.0")
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public @interface ExceptionHandler {
54+
55+
/**
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* Returns the type of exceptions caught by the exception handler.
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*
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* @return the exception type
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*/
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@NonNull Class<? extends Throwable> value();
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}

‎cloud-annotations/src/main/java/cloud/commandframework/annotations/exception/ExceptionHandlerFactory.java‎

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//
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// MIT License
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//
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// Copyright (c) 2022 Alexander Söderberg & Contributors
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
7+
// of this software and associated documentation files (the "Software"), to deal
8+
// in the Software without restriction, including without limitation the rights
9+
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10+
// copies of the Software, and to permit persons to whom the Software is
11+
// furnished to do so, subject to the following conditions:
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//
13+
// The above copyright notice and this permission notice shall be included in all
14+
// copies or substantial portions of the Software.
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//
16+
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18+
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19+
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20+
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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//
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package cloud.commandframework.annotations.exception;
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26+
import cloud.commandframework.exceptions.handling.ExceptionHandler;
27+
import java.lang.reflect.Method;
28+
import org.apiguardian.api.API;
29+
import org.checkerframework.checker.nullness.qual.NonNull;
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31+
@FunctionalInterface
32+
@API(status = API.Status.STABLE, since = "2.0.0")
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public interface ExceptionHandlerFactory<C> {
34+
35+
/**
36+
* Returns a factory that produces {@link MethodExceptionHandler} instances.
37+
*
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* @param <C> the command sender type
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* @return the created factory
40+
*/
41+
static <C> @NonNull ExceptionHandlerFactory<C> defaultFactory() {
42+
return MethodExceptionHandler::new;
43+
}
44+
45+
/**
46+
* Creates an exception handler using the given {@code method}.
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*
48+
* @param instance the parsed instance
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* @param method the exception handler method
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* @return the method handler
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*/
52+
@NonNull ExceptionHandler<C, Throwable> createExceptionHandler(@NonNull Object instance, @NonNull Method method);
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}

‎cloud-annotations/src/main/java/cloud/commandframework/annotations/exception/MethodExceptionHandler.java‎

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//
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// MIT License
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//
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// Copyright (c) 2022 Alexander Söderberg & Contributors
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
7+
// of this software and associated documentation files (the "Software"), to deal
8+
// in the Software without restriction, including without limitation the rights
9+
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10+
// copies of the Software, and to permit persons to whom the Software is
11+
// furnished to do so, subject to the following conditions:
12+
//
13+
// The above copyright notice and this permission notice shall be included in all
14+
// copies or substantial portions of the Software.
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//
16+
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17+
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18+
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19+
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20+
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21+
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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//
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package cloud.commandframework.annotations.exception;
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26+
import cloud.commandframework.exceptions.handling.ExceptionContext;
27+
import cloud.commandframework.exceptions.handling.ExceptionHandler;
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import java.lang.invoke.MethodHandle;
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import java.lang.invoke.MethodHandles;
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import java.lang.reflect.Method;
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import java.util.ArrayList;
32+
import java.util.List;
33+
import org.apiguardian.api.API;
34+
import org.checkerframework.checker.nullness.qual.NonNull;
35+
36+
/**
37+
* Represents a method annotated with {@link cloud.commandframework.annotations.exception.ExceptionHandler}.
38+
*
39+
* @param <C> the command sender type
40+
* @since 2.0.0
41+
*/
42+
@API(status = API.Status.STABLE, since = "2.0.0")
43+
public final class MethodExceptionHandler<C> implements ExceptionHandler<C, Throwable> {
44+
45+
private final Class<?>[] parameters;
46+
private final MethodHandle methodHandle;
47+
48+
/**
49+
* Creates a new handler.
50+
*
51+
* @param instance the parsed instance
52+
* @param method the method
53+
*/
54+
public MethodExceptionHandler(
55+
final @NonNull Object instance,
56+
final @NonNull Method method
57+
) {
58+
this.parameters = method.getParameterTypes();
59+
try {
60+
this.methodHandle = MethodHandles.lookup().unreflect(method).bindTo(instance);
61+
} catch (final IllegalAccessException e) {
62+
throw new RuntimeException(e);
63+
}
64+
}
65+
66+
@Override
67+
public void handle(final @NonNull ExceptionContext<C, Throwable> context) throws Throwable {
68+
final List<Object> arguments = new ArrayList<>(this.parameters.length);
69+
for (final Class<?> argument : this.parameters) {
70+
if (argument.isInstance(context)) {
71+
arguments.add(context);
72+
} else if (argument.isInstance(context.exception())) {
73+
arguments.add(context.exception());
74+
} else if (argument.isInstance(context.context())) {
75+
arguments.add(context.context());
76+
} else if (argument.isInstance(context.context().getSender())) {
77+
arguments.add(context.context().getSender());
78+
} else {
79+
arguments.add(context.context().inject(argument).orElseThrow(() ->
80+
new IllegalArgumentException("Can't map argument of type " + argument.getName())));
81+
}
82+
}
83+
this.methodHandle.invokeWithArguments(arguments);
84+
}
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}

‎cloud-annotations/src/main/java/cloud/commandframework/annotations/exception/package-info.java‎

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/**
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* Classes related to {@link cloud.commandframework.annotations.exception.ExceptionHandler}-annotated methods
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*/
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package cloud.commandframework.annotations.exception;

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