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

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Here is the source code for com.lithium.flow.config.BaseConfig.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 com.lithium.flow.config.exception.IllegalConfigException;
import com.lithium.flow.store.Store;

import java.util.Set;

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

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;

/**
 * Base immutable implementation of {@link Config}.
 *
 * @author Matt Ayres
 */
public final class BaseConfig extends AbstractConfig {
    private final String name;
    private final Store store;
    private final Config defaults;
    private final boolean allowUndefined;

    public BaseConfig(@Nonnull String name, @Nonnull Store store) {
        this(name, store, Configs.empty(), false);
    }

    public BaseConfig(@Nonnull String name, @Nonnull Store store, @Nullable Config defaults,
            boolean allowUndefined) {
        this.name = checkNotNull(name);
        this.store = checkNotNull(store);
        this.defaults = defaults;
        this.allowUndefined = allowUndefined;
    }

    @Override
    @Nonnull
    public final String getName() {
        return name;
    }

    @Override
    public boolean isAllowUndefined() {
        return allowUndefined;
    }

    @Override
    public final boolean containsKey(@Nonnull String key) {
        checkNotNull(key);
        try {
            return getValue(key, null, true, null, null) != null;
        } catch (IllegalConfigException e) {
            return false;
        }
    }

    @Override
    @Nullable
    public final String getRaw(@Nonnull String key) {
        checkNotNull(key);
        String value = store.getValue(key);
        return value != null ? value : defaults != null ? defaults.getRaw(key) : null;
    }

    @Override
    @Nonnull
    public Set<String> keySet() {
        ImmutableSet.Builder<String> builder = ImmutableSet.builder();
        if (defaults != null) {
            builder.addAll(defaults.keySet());
        }
        builder.addAll(store.getKeys());
        return builder.build();
    }

    @Override
    @Nullable
    public final String getValue(@Nonnull String key, @Nullable String defaultValue, boolean defaultSpecified,
            @Nullable Config outerConfig, @Nullable Set<String> usedKeys) {
        checkNotNull(key);

        Config varConfig = outerConfig != null ? outerConfig : this;

        String value = store.getValue(key);
        if (value != null) {
            StringBuilder sb = new StringBuilder();

            int index = 0;
            while (index < value.length()) {
                int index1 = value.indexOf("${", index);
                if (index1 == -1) {
                    break;
                }

                int index2 = value.indexOf("}", index1 + 2);
                if (index2 == -1) {
                    break;
                }

                sb.append(value.substring(index, index1));

                String subKey = value.substring(index1 + 2, index2);
                if (usedKeys == null) {
                    usedKeys = Sets.newHashSet();
                }
                if (usedKeys.add(subKey)) {
                    String subValue = varConfig.getValue(subKey, null, true, varConfig, usedKeys);
                    usedKeys.remove(subKey);
                    if (subValue != null) {
                        sb.append(subValue);
                    } else if (varConfig.isAllowUndefined()) {
                        sb.append("${").append(subKey).append("}");
                    } else {
                        throw new IllegalConfigException(subKey);
                    }
                } else {
                    throw new IllegalConfigException(key, value, "recursive", null);
                }

                index = index2 + 1;
            }

            sb.append(value.substring(index));

            return sb.toString();
        } else if (defaults != null) {
            return defaults.getValue(key, defaultValue, defaultSpecified, varConfig, null);
        } else if (defaultSpecified || varConfig.isAllowUndefined()) {
            return defaultValue;
        } else {
            throw new IllegalConfigException(key);
        }
    }
}