com.google.cloud.hadoop.util.ConfigurationUtil.java Source code

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Here is the source code for com.google.cloud.hadoop.util.ConfigurationUtil.java

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/**
 * Copyright 2013 Google Inc. All Rights Reserved.
 * 
 * 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.google.cloud.hadoop.util;

import com.google.common.base.Joiner;
import com.google.common.base.Strings;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;

/**
 * Helpers for checking the validity of Hadoop configurations.
 */
public class ConfigurationUtil {
    /**
     * Gets value for the given key or throws if value is not found.
     */
    public static String getMandatoryConfig(Configuration config, String key) throws IOException {
        String value = config.get(key);
        if (Strings.isNullOrEmpty(value)) {
            throw new IOException("Must supply a value for configuration setting: " + key);
        }
        return value;
    }

    /**
     * Gets value for the given keys or throws if one or more values are not found.
     */
    public static Map<String, String> getMandatoryConfig(Configuration config, List<String> keys)
            throws IOException {
        List<String> missingKeys = new ArrayList<>();
        Map<String, String> values = new HashMap<>();
        for (String key : keys) {
            String value = config.get(key);
            if (Strings.isNullOrEmpty(value)) {
                missingKeys.add(key);
            } else {
                values.put(key, value);
            }
        }
        if (missingKeys.size() > 0) {
            Joiner joiner = Joiner.on(", ");
            String message = "Must supply value for configuration settings: " + joiner.join(missingKeys);
            throw new IOException(message);
        }
        return values;
    }
}