com.netflix.archaius.config.PrefixedViewConfig Maven / Gradle / Ivy

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/**
 * Copyright 2015 Netflix, 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.netflix.archaius.config;

import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.NoSuchElementException;

import com.netflix.archaius.Config;
import com.netflix.archaius.ConfigListener;
import com.netflix.archaius.Decoder;
import com.netflix.archaius.StrInterpolator;

/**
 * View into another Config for properties starting with a specified prefix.
 * 
 * This class is meant to work with dynamic Config object that may have properties
 * added and removed.
 * 
 * @author elandau
 *
 */
public class PrefixedViewConfig extends DelegatingConfig {
    private final Config config;
    private final String prefix;
    
    public PrefixedViewConfig(String prefix, Config config) {
        super(config.getName() + "|" + prefix);
        
        this.config = config;
        this.prefix = prefix.endsWith(".") ? prefix : prefix + ".";
    }

    @Override
    public Iterator getKeys() {
        LinkedHashSet result = new LinkedHashSet();
        Iterator iter = config.getKeys();
        while (iter.hasNext()) {
            String key = iter.next();
            if (key.startsWith(prefix)) {
                result.add(key.substring(prefix.length()));
            }
        }
        return result.iterator();
    }

    @Override
    public boolean containsKey(String key) {
        return config.containsKey(prefix + key);
    }

    @Override
    public boolean isEmpty() {
        // This is terribly inefficient
        return !config.getKeys().hasNext();
    }

    @Override
    public void accept(Visitor visitor) {
        config.accept(visitor);
    }

    @Override
    protected Config getConfigWithProperty(String key, boolean failOnNotFound) {
        if (config.containsKey(prefix + key)) {
            return config;
        }
        if (failOnNotFound)
            throw new NoSuchElementException("No child configuration has property " + key);
        return null;
    }

    @Override
    public synchronized void setDecoder(Decoder decoder)
    {
        super.setDecoder(decoder);
        config.setDecoder(decoder);
    }

    @Override
    public synchronized void setStrInterpolator(StrInterpolator interpolator)
    {
        super.setStrInterpolator(interpolator);
        config.setStrInterpolator(interpolator);
    }

    @Override
    public synchronized void addListener(ConfigListener listener)
    {
        super.addListener(listener);
        config.addListener(listener);
    }

    @Override
    public synchronized void removeListener(ConfigListener listener)
    {
        super.removeListener(listener);
        config.removeListener(listener);
    }
}