/*
* Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com
* The software in this package is published under the terms of the CPAL v1.0
* license, a copy of which has been included with this distribution in the
* LICENSE.txt file.
*/
package org.mule.runtime.module.extension.internal.metadata;
import static org.mule.runtime.api.i18n.I18nMessageFactory.createStaticMessage;
import static org.mule.runtime.api.util.Preconditions.checkArgument;
import static org.mule.runtime.core.util.ClassUtils.getClassName;
import org.mule.runtime.api.exception.MuleRuntimeException;
import org.mule.runtime.api.metadata.resolving.NamedTypeResolver;
import org.mule.runtime.core.internal.metadata.NullMetadataResolverSupplier;
import org.mule.runtime.core.util.ClassUtils;
import org.mule.runtime.extension.api.metadata.NullMetadataResolver;
import java.util.function.Supplier;
/**
* {@link Supplier} implementation that returns instances of type {@link T} from a given {@link Class}
*
* @since 4.0
* @param <T> The type of the instances to supply
*/
public final class ResolverSupplier<T extends NamedTypeResolver> implements Supplier<T> {
private static final NullMetadataResolverSupplier NULL_METADATA_RESOLVER_SUPPLIER = new NullMetadataResolverSupplier();
private Class<T> clazz;
private ResolverSupplier(Class<T> clazz) {
this.clazz = clazz;
}
/**
* Creates a new {@link Supplier} instance, which will return instances of the given {@link Class}.
* </p>
* If the given {@link Class} is a {@link NullMetadataResolver}, the supplier will return
* a {@link NullMetadataResolverSupplier}.
*
* @param aClass The from which the {@link Supplier} will create instances
* @param <T> The {@link Class} type
*/
public static <T extends NamedTypeResolver> Supplier<T> of(Class<T> aClass) {
checkArgument(aClass != null, "The class can't be null");
if (aClass.equals(NullMetadataResolver.class)) {
return (Supplier<T>) NULL_METADATA_RESOLVER_SUPPLIER;
} else {
return new ResolverSupplier<>(aClass);
}
}
@Override
public T get() {
return instantiateResolver(clazz);
}
private T instantiateResolver(Class<T> factoryType) {
try {
return ClassUtils.instanciateClass(factoryType);
} catch (Exception e) {
throw new MuleRuntimeException(createStaticMessage("Could not create instance of type "
+ getClassName(factoryType)), e);
}
}
}