| /* |
| * 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.harmony.luni.util; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.lang.reflect.Field; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** |
| * The class contains static {@link java.io.InputStream} utilities. |
| */ |
| public class InputStreamHelper { |
| |
| /** |
| * Provides access to a protected underlying buffer of |
| * <code>ByteArrayInputStream</code>. |
| */ |
| private static final Field BAIS_BUF; |
| |
| /** |
| * Provides access to a protected position in the underlying buffer of |
| * <code>ByteArrayInputStream</code>. |
| */ |
| private static final Field BAIS_POS; |
| |
| static { |
| final Field[] f = new Field[2]; |
| AccessController.doPrivileged(new PrivilegedAction<Object>() { |
| public Object run() { |
| try { |
| f[0] = ByteArrayInputStream.class.getDeclaredField("buf"); //$NON-NLS-1$ |
| f[0].setAccessible(true); |
| f[1] = ByteArrayInputStream.class.getDeclaredField("pos"); //$NON-NLS-1$ |
| f[1].setAccessible(true); |
| } catch (NoSuchFieldException nsfe) { |
| throw new InternalError(nsfe.getLocalizedMessage()); |
| } |
| return null; |
| } |
| }); |
| BAIS_BUF = f[0]; |
| BAIS_POS = f[1]; |
| } |
| |
| /** |
| * The extension of <code>ByteArrayInputStream</code> which exposes an |
| * underlying buffer. |
| */ |
| static class ExposedByteArrayInputStream extends ByteArrayInputStream { |
| |
| /** |
| * @see java.io.ByteArrayInputStream(byte[]) |
| */ |
| public ExposedByteArrayInputStream(byte buf[]) { |
| super(buf); |
| } |
| |
| /** |
| * @see java.io.ByteArrayInputStream(byte[], int, int) |
| */ |
| public ExposedByteArrayInputStream(byte buf[], int offset, int length) { |
| super(buf, offset, length); |
| } |
| |
| /** |
| * Reads the whole stream and returns the stream snapshot. |
| */ |
| public synchronized byte[] expose() { |
| if (pos == 0 && count == buf.length) { |
| skip(count); |
| return buf; |
| } |
| |
| final int available = available(); |
| final byte[] buffer = new byte[available]; |
| System.arraycopy(buf, pos, buffer, 0, available); |
| skip(available); |
| return buffer; |
| } |
| } |
| |
| /** |
| * Reads all bytes from {@link java.io.ByteArrayInputStream} using its |
| * underlying buffer directly. |
| * |
| * @return an underlying buffer, if a current position is at the buffer |
| * beginning, and an end position is at the buffer end, or a copy of |
| * the underlying buffer part. |
| */ |
| private static byte[] expose(ByteArrayInputStream bais) { |
| byte[] buffer, buf; |
| int pos; |
| synchronized (bais) { |
| int available = bais.available(); |
| try { |
| buf = (byte[]) BAIS_BUF.get(bais); |
| pos = BAIS_POS.getInt(bais); |
| } catch (IllegalAccessException iae) { |
| throw new InternalError(iae.getLocalizedMessage()); |
| } |
| if (pos == 0 && available == buf.length) { |
| buffer = buf; |
| } else { |
| buffer = new byte[available]; |
| System.arraycopy(buf, pos, buffer, 0, available); |
| } |
| bais.skip(available); |
| } |
| return buffer; |
| } |
| |
| /** |
| * The utility method for reading the whole input stream into a snapshot |
| * buffer. To speed up the access it works with an underlying buffer for a |
| * given {@link java.io.ByteArrayInputStream}. |
| * |
| * @param is |
| * the stream to be read. |
| * @return the snapshot wrapping the buffer where the bytes are read to. |
| * @throws UnsupportedOperationException |
| * if the input stream data cannot be exposed |
| */ |
| public static byte[] expose(InputStream is) throws IOException, |
| UnsupportedOperationException { |
| if (is instanceof ExposedByteArrayInputStream) { |
| return ((ExposedByteArrayInputStream) is).expose(); |
| } |
| |
| if (is.getClass().equals(ByteArrayInputStream.class)) { |
| return expose((ByteArrayInputStream) is); |
| } |
| |
| // We don't know how to do this |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Reads all the bytes from the given input stream. |
| * |
| * Calls read multiple times on the given input stream until it receives an |
| * end of file marker. Returns the combined results as a byte array. Note |
| * that this method may block if the underlying stream read blocks. |
| * |
| * @param is |
| * the input stream to be read. |
| * @return the content of the stream as a byte array. |
| * @throws IOException |
| * if a read error occurs. |
| */ |
| public static byte[] readFullyAndClose(InputStream is) throws IOException { |
| |
| try { |
| // Initial read |
| byte[] buffer = new byte[1024]; |
| int count = is.read(buffer); |
| int nextByte = is.read(); |
| |
| // Did we get it all in one read? |
| if (nextByte == -1) { |
| byte[] dest = new byte[count]; |
| System.arraycopy(buffer, 0, dest, 0, count); |
| return dest; |
| } |
| |
| // Requires additional reads |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(count * 2); |
| baos.write(buffer, 0, count); |
| baos.write(nextByte); |
| while (true) { |
| count = is.read(buffer); |
| if (count == -1) { |
| return baos.toByteArray(); |
| } |
| baos.write(buffer, 0, count); |
| } |
| } finally { |
| is.close(); |
| } |
| } |
| } |