ConfigurationProvider.java

/*
 * Copyright 2010 Proofpoint, Inc.
 *
 * 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.airlift.configuration;

import com.google.inject.Provider;

import javax.inject.Inject;

import java.util.Objects;
import java.util.Optional;

import static com.google.common.base.MoreObjects.toStringHelper;
import static java.util.Objects.requireNonNull;

// Note this class must implement com.google.inject.Provider for the Guice element inspection code to
class ConfigurationProvider<T>
        implements Provider<T>
{
    private final ConfigurationBinding<T> configurationBinding;
    private ConfigurationFactory configurationFactory;
    private Optional<Object> bindingSource;

    public ConfigurationProvider(ConfigurationBinding<T> configurationBinding)
    {
        this.configurationBinding = requireNonNull(configurationBinding, "configurationBinding is null");
    }

    @Inject
    public void setConfigurationFactory(ConfigurationFactory configurationFactory)
    {
        this.configurationFactory = configurationFactory;
    }

    public ConfigurationBinding<T> getConfigurationBinding()
    {
        return configurationBinding;
    }

    public Optional<Object> getBindingSource()
    {
        return bindingSource;
    }

    public void setBindingSource(Optional<Object> bindingSource)
    {
        this.bindingSource = bindingSource;
    }

    @Override
    public T get()
    {
        requireNonNull(configurationFactory, "configurationFactory");

        return configurationFactory.build(this);
    }

    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        ConfigurationProvider<?> that = (ConfigurationProvider<?>) o;
        return Objects.equals(configurationBinding, that.configurationBinding);
    }

    @Override
    public int hashCode()
    {
        return Objects.hash(configurationBinding);
    }

    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("configurationBinding", configurationBinding)
                .toString();
    }
}