org.springframework.core.KotlinDetector Maven / Gradle / Ivy
/*
* Copyright 2002-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.core;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import org.springframework.lang.Nullable;
import org.springframework.util.ClassUtils;
/**
* A common delegate for detecting Kotlin's presence and for identifying Kotlin types.
*
* @author Juergen Hoeller
* @author Sebastien Deleuze
* @since 5.0
*/
@SuppressWarnings("unchecked")
public abstract class KotlinDetector {
@Nullable
private static final Class kotlinMetadata;
private static final boolean kotlinReflectPresent;
static {
Class metadata;
ClassLoader classLoader = KotlinDetector.class.getClassLoader();
try {
metadata = ClassUtils.forName("kotlin.Metadata", classLoader);
}
catch (ClassNotFoundException ex) {
// Kotlin API not available - no Kotlin support
metadata = null;
}
kotlinMetadata = (Class) metadata;
kotlinReflectPresent = ClassUtils.isPresent("kotlin.reflect.full.KClasses", classLoader);
}
/**
* Determine whether Kotlin is present in general.
*/
public static boolean isKotlinPresent() {
return (kotlinMetadata != null);
}
/**
* Determine whether Kotlin reflection is present.
* @since 5.1
*/
public static boolean isKotlinReflectPresent() {
return kotlinReflectPresent;
}
/**
* Determine whether the given {@code Class} is a Kotlin type
* (with Kotlin metadata present on it).
*/
public static boolean isKotlinType(Class clazz) {
return (kotlinMetadata != null && clazz.getDeclaredAnnotation(kotlinMetadata) != null);
}
/**
* Return {@code true} if the method is a suspending function.
* @since 5.3
*/
public static boolean isSuspendingFunction(Method method) {
if (KotlinDetector.isKotlinType(method.getDeclaringClass())) {
Class[] types = method.getParameterTypes();
if (types.length > 0 && "kotlin.coroutines.Continuation".equals(types[types.length - 1].getName())) {
return true;
}
}
return false;
}
}