com.evilco.license.client.decoder.CompressedLicenseDecoder.java Source code

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Here is the source code for com.evilco.license.client.decoder.CompressedLicenseDecoder.java

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/**
 * Copyright (C) 2014 Evil-Co <http://wwww.evil-co.com>
 *
 * 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.evilco.license.client.decoder;

import com.evilco.license.common.ILicense;
import com.evilco.license.common.exception.LicenseDecoderException;
import com.google.common.base.CharMatcher;
import com.google.common.io.BaseEncoding;
import org.apache.commons.io.IOUtils;

import javax.annotation.Nonnull;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;

/**
 * Provides a compressed text-based decoder.
 * @author         Johannes "Akkarin" Donath <johannesd@evil-co.com>
 * @copyright         Copyright (C) 2014 Evil-Co <http://www.evil-co.com>
 */
public class CompressedLicenseDecoder implements ILicenseDecoder<String> {

    /**
     * Stores the child decoder.
     */
    protected final ILicenseDecoder childDecoder;

    /**
     * Constructs a new CompressedLicenseDecoder.
     * @param decoder
     */
    public CompressedLicenseDecoder(ILicenseDecoder decoder) {
        this.childDecoder = decoder;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <T extends ILicense> T decode(@Nonnull DataInputStream inputStream, @Nonnull Class<T> licenseType)
            throws IOException, LicenseDecoderException {
        throw new UnsupportedOperationException(
                "Decoding compressed licenses from DataInputStreams is not supported.");
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <T extends ILicense> T decode(@Nonnull String input, @Nonnull Class<T> licenseType)
            throws LicenseDecoderException {
        // define streams
        ByteArrayInputStream inputStream = null;
        GZIPInputStream gzipInputStream = null;
        DataInputStream dataInputStream = null;

        // read data
        try {
            // remove newlines
            input = CharMatcher.anyOf("\n\r").removeFrom(input);

            // decode data
            byte[] data = BaseEncoding.base64().decode(input);

            // create streams
            inputStream = new ByteArrayInputStream(data);
            gzipInputStream = new GZIPInputStream(inputStream);
            dataInputStream = new DataInputStream(gzipInputStream);

            // decode data
            return ((T) this.childDecoder.decode(dataInputStream, licenseType));
        } catch (IOException ex) {
            throw new LicenseDecoderException(ex.getMessage(), ex);
        } finally {
            IOUtils.closeQuietly(dataInputStream);
            IOUtils.closeQuietly(gzipInputStream);
            IOUtils.closeQuietly(inputStream);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isAvailable() {
        return this.childDecoder.isAvailable();
    }
}