com.google.inject.internal.KotlinSupport Maven / Gradle / Ivy
package com.google.inject.internal;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.function.Predicate;
/**
* Class to conditionally load support for Kotlin features. These features are enabled based on
* whether {@code com.google.inject.kotlin.KotlinSupportImpl} is in the class path.
*/
public final class KotlinSupport {
private KotlinSupport() {} // no instantiation
public static KotlinSupportInterface getInstance() {
return KotlinSupportHolder.INSTANCE;
}
private static class KotlinSupportHolder {
static final KotlinSupportInterface INSTANCE = loadKotlinSupport();
}
private static KotlinSupportInterface loadKotlinSupport() {
try {
@SuppressWarnings("unchecked")
Class kotlinSupportClass =
(Class)
Class.forName("com.google.inject.kotlin.KotlinSupportImpl");
Field instance = kotlinSupportClass.getField("INSTANCE");
instance.setAccessible(true);
return (KotlinSupportInterface) instance.get(null);
} catch (ReflectiveOperationException e) {
return new KotlinUnsupported();
}
}
private static class KotlinUnsupported implements KotlinSupportInterface {
static final Annotation[] NO_ANNOTATIONS = new Annotation[0];
static final Predicate FALSE_PREDICATE = integer -> false;
@Override
public Annotation[] getAnnotations(Field field) {
return NO_ANNOTATIONS;
}
@Override
public boolean isNullable(Field field) {
return false;
}
@Override
public Predicate getIsParameterKotlinNullablePredicate(Constructor constructor) {
return FALSE_PREDICATE;
}
@Override
public Predicate getIsParameterKotlinNullablePredicate(Method method) {
return FALSE_PREDICATE;
}
@Override
public void checkConstructorParameterAnnotations(Constructor constructor, Errors errors) {
// do nothing
}
@Override
public boolean isLocalClass(Class clazz) {
return false;
}
}
}