com.lithium.flow.config.PrefixConfig.java Source code

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Here is the source code for com.lithium.flow.config.PrefixConfig.java

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/*
 * Copyright 2015 Lithium Technologies, 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 com.lithium.flow.config;

import static com.google.common.base.Preconditions.checkNotNull;

import java.util.Collections;
import java.util.Map;
import java.util.Set;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import com.google.common.collect.Maps;

/**
 * @author Matt Ayres
 */
public class PrefixConfig extends AbstractConfig {
    private final Config delegate;
    private final String prefix;

    public PrefixConfig(@Nonnull Config delegate, @Nonnull String prefix) {
        this.delegate = checkNotNull(delegate);
        this.prefix = checkNotNull(prefix) + ".";
    }

    @Nonnull
    private String prefixKey(@Nonnull String key) {
        return prefix + key;
    }

    @Override
    @Nonnull
    public String getName() {
        return delegate.getName();
    }

    @Override
    public boolean isAllowUndefined() {
        return delegate.isAllowUndefined();
    }

    @Override
    public boolean containsKey(@Nonnull String key) {
        return delegate.containsKey(prefixKey(key)) || delegate.containsKey(key);
    }

    @Override
    @Nullable
    public String getRaw(@Nonnull String key) {
        checkNotNull(key);
        String prefixKey = prefixKey(key);
        String raw = delegate.getRaw(prefixKey);
        return raw == null ? delegate.getRaw(key) : raw;
    }

    @Override
    public String getValue(@Nonnull String key, @Nullable String defVal, boolean defaultSpecified,
            @Nullable Config outerConfig, @Nullable Set<String> usedKeys) {
        String prefixKey = prefixKey(key);

        // Config used to supply variable substitutions to inner config
        Config varConfig = (outerConfig != null) ? outerConfig : this;

        String retVal = delegate.getValue(prefixKey, null, true, varConfig, usedKeys);
        if (retVal == null) {
            retVal = delegate.getValue(key, defVal, defaultSpecified, varConfig, usedKeys);
        }
        return retVal;
    }

    @Override
    @Nonnull
    public Set<String> keySet() {
        return asRawMap().keySet();
    }

    @Override
    @Nonnull
    public Map<String, String> asRawMap() {
        Map<String, String> rawMap = Maps.newLinkedHashMap();
        Map<String, String> baseRawMap = delegate.asRawMap();
        rawMap.putAll(baseRawMap);

        for (Map.Entry<String, String> configEntries : baseRawMap.entrySet()) {
            String key = configEntries.getKey();
            String value = configEntries.getValue();

            if (key.startsWith(prefix) && !key.equals(prefix)) {
                rawMap.put(key.substring(prefix.length()), value);
            }
        }

        return Collections.unmodifiableMap(rawMap);
    }
}