io.helidon.integrations.oci.sdk.cdi.MicroProfileConfigConfigAccessor Maven / Gradle / Ivy
/*
* Copyright (c) 2024 Oracle and/or its affiliates.
*
* 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 io.helidon.integrations.oci.sdk.cdi;
import java.util.Objects;
import java.util.Optional;
import java.util.function.Supplier;
import org.eclipse.microprofile.config.Config;
import org.eclipse.microprofile.config.ConfigProvider;
/**
* A {@link ConfigAccessor} implementation backed by MicroProfile Config constructs.
*
* @see #get(String)
*
* @see #MicroProfileConfigConfigAccessor(Supplier)
*/
class MicroProfileConfigConfigAccessor implements ConfigAccessor {
/*
* Instance fields.
*/
/**
* A {@link Supplier} of {@link Config} instances.
*/
private final Supplier cs;
/*
* Constructors.
*/
/**
* Creates a new {@link MicroProfileConfigConfigAccessor}.
*
* This constructor calls the {@link #MicroProfileConfigConfigAccessor(Supplier)} constructor with a reference to
* the {@link ConfigProvider#getConfig()} method.
*
* @see #MicroProfileConfigConfigAccessor(Supplier)
*/
MicroProfileConfigConfigAccessor() {
this(ConfigProvider::getConfig);
}
/**
* Creates a new {@link MicroProfileConfigConfigAccessor}.
*
* This constructor calls the {@link #MicroProfileConfigConfigAccessor(Supplier)} constructor with a {@link
* Supplier} that always returns the supplied {@link Config} from its {@link Supplier#get() get()} method.
*
* @param c a {@link Config} instance; must not be {@code null}
*
* @exception NullPointerException if {@code c} is {@code null}
*
* @see #MicroProfileConfigConfigAccessor(Supplier)
*/
MicroProfileConfigConfigAccessor(Config c) {
this(supplier(c));
}
/**
* Creates a new {@link MicroProfileConfigConfigAccessor}.
*
* @param cs a {@link Supplier} of {@link Config} instances; must not be {@code null}
*
* @exception NullPointerException if {@code cs} is {@code null}
*/
MicroProfileConfigConfigAccessor(Supplier cs) {
super();
this.cs = Objects.requireNonNull(cs, "cs");
}
/*
* Instance methods.
*/
/**
* Calls the {@link Config#getOptionalValue(String, Class)} method with the supplied {@code name} and {@link String
* String.class} as its arguments and returns its result.
*
* @param name the configuration name; must not be {@code null}
*
* @return the result of invoking {@link Config#getOptionalValue(String, Class)} with the supplied {@code name} and {@link String
* String.class} as its arguments; never {@code null}
*
* @exception NullPointerException if {@code name} is {@code null}, or if the {@link Supplier} of {@link Config}
* instances {@linkplain #MicroProfileConfigConfigAccessor(Supplier) supplied at construction time} returns {@code
* null} (illegally) from its {@link Supplier#get() get()} method
*
* @see Config#getOptionalValue(String, Class)
*/
@Override
public Optional get(String name) {
// MicroProfile Config imlementations are (very surprisingly) not obligated to detect null names. Handle this
// case early.
Objects.requireNonNull(name, "name");
// The MicroProfile Config specification and javadocs say nothing about whether getOptionalValue(String, Class)
// can return null. The TCK implies that (thankfully) it must not. We follow that implication.
return Optional.ofNullable(this.cs.get())
.flatMap(c -> c.getOptionalValue(name, String.class));
}
/*
* Static methods.
*/
/**
* Returns a memoized {@link Supplier} that returns the supplied {@link Config} on every invocation of its {@link
* Supplier#get() get()} method, assuming the supplied {@link Config} is non-{@code null}.
*
* @param c the {@link Config} to return; must not be {@code null}
*
* @return a {@link Supplier} that returns the supplied {@link Config} on every invocation of its {@link
* Supplier#get() get()} method; never {@code null}
*
* @exception NullPointerException if {@code c} is {@code null}
*/
private static Supplier supplier(Config c) {
Objects.requireNonNull(c, "c");
return () -> c;
}
}