001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *
010 *        http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License.
018 */
019
020package org.apache.isis.core.commons.lang;
021
022import java.io.ByteArrayInputStream;
023import java.io.IOException;
024import java.io.InputStream;
025import java.io.OutputStream;
026import java.io.UnsupportedEncodingException;
027
028public final class InputStreamExtensions {
029
030    private static final int DEFAULT_BUFFER_SIZE = 1024;
031
032    private InputStreamExtensions() {
033    }
034
035    /**
036     * Copy bytes from an <code>InputStream</code> to an
037     * <code>OutputStream</code>.
038     * <p>
039     * This method buffers the input internally, so there is no need to use a
040     * <code>BufferedInputStream</code>.
041     * 
042     * @param extendee
043     *            the <code>InputStream</code> to read from
044     * @param output
045     *            the <code>OutputStream</code> to write to
046     * @return the number of bytes copied
047     * @throws IllegalArgumentException
048     *             if the input or output is null
049     * @throws IOException
050     *             if an I/O error occurs
051     * @since Commons IO 1.1
052     */
053    public static int copyTo(final InputStream extendee, final OutputStream output) throws IOException {
054        if (extendee == null) {
055            throw new IllegalArgumentException("InputStream cannot be null");
056        }
057        if (output == null) {
058            throw new IllegalArgumentException("OutputStream cannot be null");
059        }
060        final byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
061        int count = 0;
062        int n = 0;
063        while (-1 != (n = extendee.read(buffer))) {
064            output.write(buffer, 0, n);
065            count += n;
066        }
067        return count;
068    }
069
070    public static InputStream asUtf8ByteStream(final String string) throws UnsupportedEncodingException {
071        final byte[] data = string.getBytes("utf-8");
072        final InputStream in = new ByteArrayInputStream(data);
073        return in;
074    }
075
076}