/*
* 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
*
* http://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.jdbi.v3.core.mapper.reflect;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.function.Function;
import org.jdbi.v3.core.internal.exceptions.Unchecked;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
class StaticMethodInstanceFactory<T> extends InstanceFactory<T> {
private final Class<T> type;
private final Function<Object[], Object> method;
StaticMethodInstanceFactory(Class<T> type, Method method) {
super(method);
this.type = requireNonNull(type, "type is null");
requireNonNull(method, "method is null");
if (!isStaticFactoryMethodFor(method, type)) {
throw new IllegalArgumentException(format("Given method \"%s\" is not a valid factory method for %s", method, type));
}
this.method = Unchecked.function(
Unchecked.function(MethodHandles.lookup()::unreflect)
.apply(method)
::invokeWithArguments);
}
private static boolean isStaticFactoryMethodFor(Method method, Class<?> type) {
return Modifier.isStatic(method.getModifiers())
&& type.isAssignableFrom(method.getReturnType());
}
@Override
T newInstance(Object... params) {
return type.cast(method.apply(params));
}
@Override
public String toString() {
return method.toString();
}
}