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/*
 * Copyright 2016 SimplifyOps, Inc. (http://simplifyops.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.
 */

/*
* Streams.java
* 
* User: greg
* Created: Feb 4, 2008 4:06:55 PM
* $Id$
*/
package com.dtolabs.utils;

import lombok.Getter;

import java.io.*;


/**
 * Streams utility class for reading and writing streams
 *
 * @author Greg Schueler [email protected]
 * @version $Revision$
 */
public class Streams {
    /**
     * Read the data from the input stream and copy to the outputstream.
     *
     * @param in  inputstream
     * @param out outpustream
     *
     * @return bytes copied
     * @throws java.io.IOException if thrown by underlying io operations
     */
    public static long copyStream(final InputStream in, final OutputStream out) throws IOException {
        return copyStreamCount(in, out);
    }

    /**
     * Read the data from the input stream and copy to the outputstream.
     *
     * @param in  inputstream
     * @param out outpustream
     *            @return number of bytes copied
     *
     * @throws java.io.IOException if thrown by underlying io operations
     */
    public static int copyStreamCount(final InputStream in, final OutputStream out) throws IOException {
        final byte[] buffer = new byte[10240];
        int tot=0;
        int c;
        c = in.read(buffer);
        while (c >= 0) {
            if (c > 0) {
                out.write(buffer, 0, c);
                tot += c;
            }
            c = in.read(buffer);
        }
        return tot;
    }
    /**
     * Read the data from the reader and copy to the writer.
     *
     * @param in  inputstream
     * @param out outpustream
     *            @return number of bytes copied
     *
     * @throws java.io.IOException if thrown by underlying io operations
     */
    public static int copyWriterCount(final Reader in, final Writer out) throws IOException {
        final char[] buffer = new char[10240];
        int tot=0;
        int c;
        c = in.read(buffer);
        while (c >= 0) {
            if (c > 0) {
                out.write(buffer, 0, c);
                tot += c;
            }
            c = in.read(buffer);
        }
        return tot;
    }

    /**
     * A simple Thread subclass that performs a stream copy from an InputStream to an OutputStream.  If an IOException
     * is thrown, it is available via {@link #getException()}.
     */
    public static class StreamCopyThread extends Thread {
        final InputStream in;
        final OutputStream out;
        @Getter private IOException exception;
        private Runnable finalizer;

        public StreamCopyThread(final InputStream in, final OutputStream out) {
            this.in = in;
            this.out = out;
        }

        public StreamCopyThread(final InputStream in, final OutputStream out, final Runnable finalizer) {
            this.in = in;
            this.out = out;
            this.finalizer = finalizer;
        }

        @Override
        public void run() {
            try {
                Streams.copyStream(in, out);
                out.flush();
            } catch (IOException e) {
                exception = e;
            } finally {
                if (null != finalizer) {
                    finalizer.run();
                }
            }
        }
    }

    /**
     * Return a new thread that will copy an inputstream to an output stream.  You must start the thread.
     *
     * @param in  inputstream
     * @param out outputstream
     *
     * @return an unstarted {@link StreamCopyThread}
     */
    public static StreamCopyThread copyStreamThread(final InputStream in, final OutputStream out) {
        return copyStreamThread(in, out, null);
    }

    /**
     * Return a new thread that will copy an inputstream to an output stream.  You must start the thread.
     *
     * @param in  inputstream
     * @param out outputstream
     * @param finalizer runnable to execute after the stream is copied or an exception occurred
     *
     * @return an unstarted {@link StreamCopyThread}
     */
    public static StreamCopyThread copyStreamThread(
            final InputStream in,
            final OutputStream out,
            final Runnable finalizer
    )
    {
        return new StreamCopyThread(in, out, finalizer);
    }
}