/*
 *  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.causeway.core.metamodel.commons;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public final class InputStreamExtensions {

    private static final int DEFAULT_BUFFER_SIZE = 1024;

    private InputStreamExtensions() {
    }

    /**
     * Copy bytes from an <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param extendee
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @return the number of bytes copied
     * @throws IllegalArgumentException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static int copyTo(final InputStream extendee, final OutputStream output) throws IOException {
        if (extendee == null) {
            throw new IllegalArgumentException("InputStream cannot be null");
        }
        if (output == null) {
            throw new IllegalArgumentException("OutputStream cannot be null");
        }
        final byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        int count = 0;
        int n = 0;
        while (-1 != (n = extendee.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

}
