| /* ==================================================================== |
| 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.poi.util; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.ReadableByteChannel; |
| |
| public final class IOUtils { |
| private IOUtils() { |
| // no instances of this class |
| } |
| |
| /** |
| * Reads all the data from the input stream, and returns the bytes read. |
| */ |
| public static byte[] toByteArray(InputStream stream) throws IOException { |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(); |
| |
| byte[] buffer = new byte[4096]; |
| int read = 0; |
| while (read != -1) { |
| read = stream.read(buffer); |
| if (read > 0) { |
| baos.write(buffer, 0, read); |
| } |
| } |
| |
| return baos.toByteArray(); |
| } |
| |
| /** |
| * Returns an array (that shouldn't be written to!) of the |
| * ByteBuffer. Will be of the requested length, or possibly |
| * longer if that's easier. |
| */ |
| public static byte[] toByteArray(ByteBuffer buffer, int length) { |
| if(buffer.hasArray() && buffer.arrayOffset() == 0) { |
| // The backing array should work out fine for us |
| return buffer.array(); |
| } |
| |
| byte[] data = new byte[length]; |
| buffer.get(data); |
| return data; |
| } |
| |
| /** |
| * Helper method, just calls <tt>readFully(in, b, 0, b.length)</tt> |
| */ |
| public static int readFully(InputStream in, byte[] b) throws IOException { |
| return readFully(in, b, 0, b.length); |
| } |
| |
| /** |
| * Same as the normal <tt>in.read(b, off, len)</tt>, but tries to ensure |
| * that the entire len number of bytes is read. |
| * <p> |
| * If the end of file is reached before any bytes are read, returns -1. If |
| * the end of the file is reached after some bytes are read, returns the |
| * number of bytes read. If the end of the file isn't reached before len |
| * bytes have been read, will return len bytes. |
| */ |
| public static int readFully(InputStream in, byte[] b, int off, int len) throws IOException { |
| int total = 0; |
| while (true) { |
| int got = in.read(b, off + total, len - total); |
| if (got < 0) { |
| return (total == 0) ? -1 : total; |
| } |
| total += got; |
| if (total == len) { |
| return total; |
| } |
| } |
| } |
| |
| /** |
| * Same as the normal <tt>channel.read(b)</tt>, but tries to ensure |
| * that the entire len number of bytes is read. |
| * <p> |
| * If the end of file is reached before any bytes are read, returns -1. If |
| * the end of the file is reached after some bytes are read, returns the |
| * number of bytes read. If the end of the file isn't reached before len |
| * bytes have been read, will return len bytes. |
| */ |
| public static int readFully(ReadableByteChannel channel, ByteBuffer b) throws IOException { |
| int total = 0; |
| while (true) { |
| int got = channel.read(b); |
| if (got < 0) { |
| return (total == 0) ? -1 : total; |
| } |
| total += got; |
| if (total == b.capacity()) { |
| return total; |
| } |
| } |
| } |
| |
| /** |
| * Copies all the data from the given InputStream to the OutputStream. It |
| * leaves both streams open, so you will still need to close them once done. |
| */ |
| public static void copy(InputStream inp, OutputStream out) throws IOException { |
| byte[] buff = new byte[4096]; |
| int count; |
| while ((count = inp.read(buff)) != -1) { |
| if (count > 0) { |
| out.write(buff, 0, count); |
| } |
| } |
| } |
| } |