org.apache.flume.channel.file.encryption.KeyProviderFactory.java Source code

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Here is the source code for org.apache.flume.channel.file.encryption.KeyProviderFactory.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.flume.channel.file.encryption;

import org.apache.flume.Context;
import org.apache.flume.FlumeException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;

public class KeyProviderFactory {
    private static final Logger logger = LoggerFactory.getLogger(KeyProviderFactory.class);

    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static KeyProvider getInstance(String keyProviderType, Context context) {
        Preconditions.checkNotNull(keyProviderType, "key provider type must not be null");

        // try to find builder class in enum of known providers
        KeyProviderType type;
        try {
            type = KeyProviderType.valueOf(keyProviderType.toUpperCase());
        } catch (IllegalArgumentException e) {
            logger.debug("Not in enum, loading provider class: {}", keyProviderType);
            type = KeyProviderType.OTHER;
        }
        Class<? extends KeyProvider.Builder> providerClass = type.getBuilderClass();

        // handle the case where they have specified their own builder in the config
        if (providerClass == null) {
            try {
                Class c = Class.forName(keyProviderType);
                if (c != null && KeyProvider.Builder.class.isAssignableFrom(c)) {
                    providerClass = (Class<? extends KeyProvider.Builder>) c;
                } else {
                    String errMessage = "Unable to instantiate Builder from " + keyProviderType;
                    logger.error(errMessage);
                    throw new FlumeException(errMessage);
                }
            } catch (ClassNotFoundException ex) {
                logger.error("Class not found: " + keyProviderType, ex);
                throw new FlumeException(ex);
            }
        }

        // build the builder
        KeyProvider.Builder provider;
        try {
            provider = providerClass.newInstance();
        } catch (InstantiationException ex) {
            String errMessage = "Cannot instantiate builder: " + keyProviderType;
            logger.error(errMessage, ex);
            throw new FlumeException(errMessage, ex);
        } catch (IllegalAccessException ex) {
            String errMessage = "Cannot instantiate builder: " + keyProviderType;
            logger.error(errMessage, ex);
            throw new FlumeException(errMessage, ex);
        }
        return provider.build(context);
    }
}