org.mule.util.compression.CompressionHelper.java Source code

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Here is the source code for org.mule.util.compression.CompressionHelper.java

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/*
 * $Id$
 * --------------------------------------------------------------------------------------
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 *
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */

package org.mule.util.compression;

import org.mule.util.ClassUtils;

import java.security.AccessController;
import java.security.PrivilegedAction;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * <code>CompressionHelper</code> a static class that provides facilities for
 * compressing and uncompressing byte arrays
 */

public final class CompressionHelper {
    /**
     * logger used by this class
     */
    private static Log logger = LogFactory.getLog(CompressionHelper.class);

    private static CompressionStrategy defaultStrategy;

    /** Do not instanciate. */
    private CompressionHelper() {
        // no-op
    }

    public static synchronized CompressionStrategy getDefaultCompressionStrategy() {
        if (defaultStrategy == null) {
            defaultStrategy = AccessController.doPrivileged(new PrivilegedAction<CompressionStrategy>() {
                @Override
                public CompressionStrategy run() {
                    try {
                        Object o = ClassUtils
                                .loadClass(CompressionStrategy.COMPRESSION_DEFAULT, CompressionHelper.class)
                                .newInstance();
                        if (logger.isDebugEnabled()) {
                            logger.debug("Found CompressionStrategy: " + o.getClass().getName());
                        }
                        return (CompressionStrategy) o;
                    } catch (Exception e) {
                        // TODO MULE-863: What should we really do?  Document this?
                        logger.warn("Failed to build compression strategy: " + e.getMessage());
                    }
                    return null;
                }
            });
        }
        return defaultStrategy;
    }

}