/* * Copyright (C) 2007 The Guava Authors * * 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. */ package net.tribe7.common.io; import static net.tribe7.common.base.Preconditions.checkArgument; import static net.tribe7.common.base.Preconditions.checkNotNull; import static net.tribe7.common.base.Preconditions.checkPositionIndex; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.DataInput; import java.io.DataInputStream; import java.io.DataOutput; import java.io.DataOutputStream; import java.io.EOFException; import java.io.FilterInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.ByteBuffer; import java.nio.channels.ReadableByteChannel; import java.nio.channels.WritableByteChannel; import java.util.Arrays; import net.tribe7.common.annotations.Beta; import net.tribe7.common.base.Function; import net.tribe7.common.collect.Iterables; import net.tribe7.common.hash.HashCode; import net.tribe7.common.hash.HashFunction; /** * Provides utility methods for working with byte arrays and I/O streams. * * @author Chris Nokleberg * @author Colin Decker * @since 1.0 */ @Beta public final class ByteStreams { private static final int BUF_SIZE = 0x1000; // 4K private ByteStreams() {} /** * Returns a factory that will supply instances of * {@link ByteArrayInputStream} that read from the given byte array. * * @param b the input buffer * @return the factory * @deprecated Use {@link ByteSource#wrap(byte[])} instead. This method is * scheduled for removal in Guava 18.0. */ @Deprecated public static InputSupplier<ByteArrayInputStream> newInputStreamSupplier( byte[] b) { return asInputSupplier(ByteSource.wrap(b)); } /** * Returns a factory that will supply instances of * {@link ByteArrayInputStream} that read from the given byte array. * * @param b the input buffer * @param off the offset in the buffer of the first byte to read * @param len the maximum number of bytes to read from the buffer * @return the factory * @deprecated Use {@code ByteSource.wrap(b).slice(off, len)} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated public static InputSupplier<ByteArrayInputStream> newInputStreamSupplier( final byte[] b, final int off, final int len) { return asInputSupplier(ByteSource.wrap(b).slice(off, len)); } /** * Writes a byte array to an output stream from the given supplier. * * @param from the bytes to write * @param to the output supplier * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSink#write(byte[])} instead. This method is * scheduled for removal in Guava 18.0. */ @Deprecated public static void write(byte[] from, OutputSupplier<? extends OutputStream> to) throws IOException { asByteSink(to).write(from); } /** * Opens input and output streams from the given suppliers, copies all * bytes from the input to the output, and closes the streams. * * @param from the input factory * @param to the output factory * @return the number of bytes copied * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSource#copyTo(ByteSink)} instead. This method * is scheduled for removal in Guava 18.0. */ @Deprecated public static long copy(InputSupplier<? extends InputStream> from, OutputSupplier<? extends OutputStream> to) throws IOException { return asByteSource(from).copyTo(asByteSink(to)); } /** * Opens an input stream from the supplier, copies all bytes from the * input to the output, and closes the input stream. Does not close * or flush the output stream. * * @param from the input factory * @param to the output stream to write to * @return the number of bytes copied * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSource#copyTo(OutputStream)} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated public static long copy(InputSupplier<? extends InputStream> from, OutputStream to) throws IOException { return asByteSource(from).copyTo(to); } /** * Opens an output stream from the supplier, copies all bytes from the input * to the output, and closes the output stream. Does not close or flush the * input stream. * * @param from the input stream to read from * @param to the output factory * @return the number of bytes copied * @throws IOException if an I/O error occurs * @since 10.0 * @deprecated Use {@link ByteSink#writeFrom(InputStream)} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated public static long copy(InputStream from, OutputSupplier<? extends OutputStream> to) throws IOException { return asByteSink(to).writeFrom(from); } /** * Copies all bytes from the input stream to the output stream. * Does not close or flush either stream. * * @param from the input stream to read from * @param to the output stream to write to * @return the number of bytes copied * @throws IOException if an I/O error occurs */ public static long copy(InputStream from, OutputStream to) throws IOException { checkNotNull(from); checkNotNull(to); byte[] buf = new byte[BUF_SIZE]; long total = 0; while (true) { int r = from.read(buf); if (r == -1) { break; } to.write(buf, 0, r); total += r; } return total; } /** * Copies all bytes from the readable channel to the writable channel. * Does not close or flush either channel. * * @param from the readable channel to read from * @param to the writable channel to write to * @return the number of bytes copied * @throws IOException if an I/O error occurs */ public static long copy(ReadableByteChannel from, WritableByteChannel to) throws IOException { checkNotNull(from); checkNotNull(to); ByteBuffer buf = ByteBuffer.allocate(BUF_SIZE); long total = 0; while (from.read(buf) != -1) { buf.flip(); while (buf.hasRemaining()) { total += to.write(buf); } buf.clear(); } return total; } /** * Reads all bytes from an input stream into a byte array. * Does not close the stream. * * @param in the input stream to read from * @return a byte array containing all the bytes from the stream * @throws IOException if an I/O error occurs */ public static byte[] toByteArray(InputStream in) throws IOException { ByteArrayOutputStream out = new ByteArrayOutputStream(); copy(in, out); return out.toByteArray(); } /** * Reads all bytes from an input stream into a byte array. The given * expected size is used to create an initial byte array, but if the actual * number of bytes read from the stream differs, the correct result will be * returned anyway. */ static byte[] toByteArray( InputStream in, int expectedSize) throws IOException { byte[] bytes = new byte[expectedSize]; int remaining = expectedSize; while (remaining > 0) { int off = expectedSize - remaining; int read = in.read(bytes, off, remaining); if (read == -1) { // end of stream before reading expectedSize bytes // just return the bytes read so far return Arrays.copyOf(bytes, off); } remaining -= read; } // bytes is now full int b = in.read(); if (b == -1) { return bytes; } // the stream was longer, so read the rest normally FastByteArrayOutputStream out = new FastByteArrayOutputStream(); out.write(b); // write the byte we read when testing for end of stream copy(in, out); byte[] result = new byte[bytes.length + out.size()]; System.arraycopy(bytes, 0, result, 0, bytes.length); out.writeTo(result, bytes.length); return result; } /** * BAOS that provides limited access to its internal byte array. */ private static final class FastByteArrayOutputStream extends ByteArrayOutputStream { /** * Writes the contents of the internal buffer to the given array starting * at the given offset. Assumes the array has space to hold count bytes. */ void writeTo(byte[] b, int off) { System.arraycopy(buf, 0, b, off, count); } } /** * Returns the data from a {@link InputStream} factory as a byte array. * * @param supplier the factory * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSource#read()} instead. This method is * scheduled for removal in Guava 18.0. */ @Deprecated public static byte[] toByteArray( InputSupplier<? extends InputStream> supplier) throws IOException { return asByteSource(supplier).read(); } /** * Returns a new {@link ByteArrayDataInput} instance to read from the {@code * bytes} array from the beginning. */ public static ByteArrayDataInput newDataInput(byte[] bytes) { return new ByteArrayDataInputStream(bytes); } /** * Returns a new {@link ByteArrayDataInput} instance to read from the {@code * bytes} array, starting at the given position. * * @throws IndexOutOfBoundsException if {@code start} is negative or greater * than the length of the array */ public static ByteArrayDataInput newDataInput(byte[] bytes, int start) { checkPositionIndex(start, bytes.length); return new ByteArrayDataInputStream(bytes, start); } private static class ByteArrayDataInputStream implements ByteArrayDataInput { final DataInput input; ByteArrayDataInputStream(byte[] bytes) { this.input = new DataInputStream(new ByteArrayInputStream(bytes)); } ByteArrayDataInputStream(byte[] bytes, int start) { this.input = new DataInputStream( new ByteArrayInputStream(bytes, start, bytes.length - start)); } @Override public void readFully(byte b[]) { try { input.readFully(b); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public void readFully(byte b[], int off, int len) { try { input.readFully(b, off, len); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public int skipBytes(int n) { try { return input.skipBytes(n); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public boolean readBoolean() { try { return input.readBoolean(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public byte readByte() { try { return input.readByte(); } catch (EOFException e) { throw new IllegalStateException(e); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public int readUnsignedByte() { try { return input.readUnsignedByte(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public short readShort() { try { return input.readShort(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public int readUnsignedShort() { try { return input.readUnsignedShort(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public char readChar() { try { return input.readChar(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public int readInt() { try { return input.readInt(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public long readLong() { try { return input.readLong(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public float readFloat() { try { return input.readFloat(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public double readDouble() { try { return input.readDouble(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public String readLine() { try { return input.readLine(); } catch (IOException e) { throw new IllegalStateException(e); } } @Override public String readUTF() { try { return input.readUTF(); } catch (IOException e) { throw new IllegalStateException(e); } } } /** * Returns a new {@link ByteArrayDataOutput} instance with a default size. */ public static ByteArrayDataOutput newDataOutput() { return new ByteArrayDataOutputStream(); } /** * Returns a new {@link ByteArrayDataOutput} instance sized to hold * {@code size} bytes before resizing. * * @throws IllegalArgumentException if {@code size} is negative */ public static ByteArrayDataOutput newDataOutput(int size) { checkArgument(size >= 0, "Invalid size: %s", size); return new ByteArrayDataOutputStream(size); } @SuppressWarnings("deprecation") // for writeBytes private static class ByteArrayDataOutputStream implements ByteArrayDataOutput { final DataOutput output; final ByteArrayOutputStream byteArrayOutputSteam; ByteArrayDataOutputStream() { this(new ByteArrayOutputStream()); } ByteArrayDataOutputStream(int size) { this(new ByteArrayOutputStream(size)); } ByteArrayDataOutputStream(ByteArrayOutputStream byteArrayOutputSteam) { this.byteArrayOutputSteam = byteArrayOutputSteam; output = new DataOutputStream(byteArrayOutputSteam); } @Override public void write(int b) { try { output.write(b); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void write(byte[] b) { try { output.write(b); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void write(byte[] b, int off, int len) { try { output.write(b, off, len); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeBoolean(boolean v) { try { output.writeBoolean(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeByte(int v) { try { output.writeByte(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeBytes(String s) { try { output.writeBytes(s); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeChar(int v) { try { output.writeChar(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeChars(String s) { try { output.writeChars(s); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeDouble(double v) { try { output.writeDouble(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeFloat(float v) { try { output.writeFloat(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeInt(int v) { try { output.writeInt(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeLong(long v) { try { output.writeLong(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeShort(int v) { try { output.writeShort(v); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public void writeUTF(String s) { try { output.writeUTF(s); } catch (IOException impossible) { throw new AssertionError(impossible); } } @Override public byte[] toByteArray() { return byteArrayOutputSteam.toByteArray(); } } private static final OutputStream NULL_OUTPUT_STREAM = new OutputStream() { /** Discards the specified byte. */ @Override public void write(int b) { } /** Discards the specified byte array. */ @Override public void write(byte[] b) { checkNotNull(b); } /** Discards the specified byte array. */ @Override public void write(byte[] b, int off, int len) { checkNotNull(b); } @Override public String toString() { return "ByteStreams.nullOutputStream()"; } }; /** * Returns an {@link OutputStream} that simply discards written bytes. * * @since 14.0 (since 1.0 as net.tribe7.common.io.NullOutputStream) */ public static OutputStream nullOutputStream() { return NULL_OUTPUT_STREAM; } /** * Wraps a {@link InputStream}, limiting the number of bytes which can be * read. * * @param in the input stream to be wrapped * @param limit the maximum number of bytes to be read * @return a length-limited {@link InputStream} * @since 14.0 (since 1.0 as net.tribe7.common.io.LimitInputStream) */ public static InputStream limit(InputStream in, long limit) { return new LimitedInputStream(in, limit); } private static final class LimitedInputStream extends FilterInputStream { private long left; private long mark = -1; LimitedInputStream(InputStream in, long limit) { super(in); checkNotNull(in); checkArgument(limit >= 0, "limit must be non-negative"); left = limit; } @Override public int available() throws IOException { return (int) Math.min(in.available(), left); } // it's okay to mark even if mark isn't supported, as reset won't work @Override public synchronized void mark(int readLimit) { in.mark(readLimit); mark = left; } @Override public int read() throws IOException { if (left == 0) { return -1; } int result = in.read(); if (result != -1) { --left; } return result; } @Override public int read(byte[] b, int off, int len) throws IOException { if (left == 0) { return -1; } len = (int) Math.min(len, left); int result = in.read(b, off, len); if (result != -1) { left -= result; } return result; } @Override public synchronized void reset() throws IOException { if (!in.markSupported()) { throw new IOException("Mark not supported"); } if (mark == -1) { throw new IOException("Mark not set"); } in.reset(); left = mark; } @Override public long skip(long n) throws IOException { n = Math.min(n, left); long skipped = in.skip(n); left -= skipped; return skipped; } } /** * Returns the length of a supplied input stream, in bytes. * * @deprecated Use {@link ByteSource#size()} instead. This method is * scheduled for removal in Guava 18.0. */ @Deprecated public static long length( InputSupplier<? extends InputStream> supplier) throws IOException { return asByteSource(supplier).size(); } /** * Returns true if the supplied input streams contain the same bytes. * * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSource#contentEquals(ByteSource)} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated public static boolean equal(InputSupplier<? extends InputStream> supplier1, InputSupplier<? extends InputStream> supplier2) throws IOException { return asByteSource(supplier1).contentEquals(asByteSource(supplier2)); } /** * Attempts to read enough bytes from the stream to fill the given byte array, * with the same behavior as {@link DataInput#readFully(byte[])}. * Does not close the stream. * * @param in the input stream to read from. * @param b the buffer into which the data is read. * @throws EOFException if this stream reaches the end before reading all * the bytes. * @throws IOException if an I/O error occurs. */ public static void readFully(InputStream in, byte[] b) throws IOException { readFully(in, b, 0, b.length); } /** * Attempts to read {@code len} bytes from the stream into the given array * starting at {@code off}, with the same behavior as * {@link DataInput#readFully(byte[], int, int)}. Does not close the * stream. * * @param in the input stream to read from. * @param b the buffer into which the data is read. * @param off an int specifying the offset into the data. * @param len an int specifying the number of bytes to read. * @throws EOFException if this stream reaches the end before reading all * the bytes. * @throws IOException if an I/O error occurs. */ public static void readFully( InputStream in, byte[] b, int off, int len) throws IOException { int read = read(in, b, off, len); if (read != len) { throw new EOFException("reached end of stream after reading " + read + " bytes; " + len + " bytes expected"); } } /** * Discards {@code n} bytes of data from the input stream. This method * will block until the full amount has been skipped. Does not close the * stream. * * @param in the input stream to read from * @param n the number of bytes to skip * @throws EOFException if this stream reaches the end before skipping all * the bytes * @throws IOException if an I/O error occurs, or the stream does not * support skipping */ public static void skipFully(InputStream in, long n) throws IOException { long toSkip = n; while (n > 0) { long amt = in.skip(n); if (amt == 0) { // Force a blocking read to avoid infinite loop if (in.read() == -1) { long skipped = toSkip - n; throw new EOFException("reached end of stream after skipping " + skipped + " bytes; " + toSkip + " bytes expected"); } n--; } else { n -= amt; } } } /** * Process the bytes of a supplied stream * * @param supplier the input stream factory * @param processor the object to which to pass the bytes of the stream * @return the result of the byte processor * @throws IOException if an I/O error occurs * @deprecated Use {@link ByteSource#read(ByteProcessor)} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated public static <T> T readBytes( InputSupplier<? extends InputStream> supplier, ByteProcessor<T> processor) throws IOException { checkNotNull(supplier); checkNotNull(processor); Closer closer = Closer.create(); try { InputStream in = closer.register(supplier.getInput()); return readBytes(in, processor); } catch (Throwable e) { throw closer.rethrow(e); } finally { closer.close(); } } /** * Process the bytes of the given input stream using the given processor. * * @param input the input stream to process * @param processor the object to which to pass the bytes of the stream * @return the result of the byte processor * @throws IOException if an I/O error occurs * @since 14.0 */ public static <T> T readBytes( InputStream input, ByteProcessor<T> processor) throws IOException { checkNotNull(input); checkNotNull(processor); byte[] buf = new byte[BUF_SIZE]; int read; do { read = input.read(buf); } while (read != -1 && processor.processBytes(buf, 0, read)); return processor.getResult(); } /** * Computes the hash code of the data supplied by {@code supplier} using {@code * hashFunction}. * * @param supplier the input stream factory * @param hashFunction the hash function to use to hash the data * @return the {@link HashCode} of all of the bytes in the input stream * @throws IOException if an I/O error occurs * @since 12.0 * @deprecated Use {@link ByteSource#hash(HashFunction)} instead. This method * is scheduled for removal in Guava 18.0. */ @Deprecated public static HashCode hash( InputSupplier<? extends InputStream> supplier, HashFunction hashFunction) throws IOException { return asByteSource(supplier).hash(hashFunction); } /** * Reads some bytes from an input stream and stores them into the buffer array * {@code b}. This method blocks until {@code len} bytes of input data have * been read into the array, or end of file is detected. The number of bytes * read is returned, possibly zero. Does not close the stream. * * <p>A caller can detect EOF if the number of bytes read is less than * {@code len}. All subsequent calls on the same stream will return zero. * * <p>If {@code b} is null, a {@code NullPointerException} is thrown. If * {@code off} is negative, or {@code len} is negative, or {@code off+len} is * greater than the length of the array {@code b}, then an * {@code IndexOutOfBoundsException} is thrown. If {@code len} is zero, then * no bytes are read. Otherwise, the first byte read is stored into element * {@code b[off]}, the next one into {@code b[off+1]}, and so on. The number * of bytes read is, at most, equal to {@code len}. * * @param in the input stream to read from * @param b the buffer into which the data is read * @param off an int specifying the offset into the data * @param len an int specifying the number of bytes to read * @return the number of bytes read * @throws IOException if an I/O error occurs */ public static int read(InputStream in, byte[] b, int off, int len) throws IOException { checkNotNull(in); checkNotNull(b); if (len < 0) { throw new IndexOutOfBoundsException("len is negative"); } int total = 0; while (total < len) { int result = in.read(b, off + total, len - total); if (result == -1) { break; } total += result; } return total; } /** * Returns an {@link InputSupplier} that returns input streams from the * an underlying supplier, where each stream starts at the given * offset and is limited to the specified number of bytes. * * @param supplier the supplier from which to get the raw streams * @param offset the offset in bytes into the underlying stream where * the returned streams will start * @param length the maximum length of the returned streams * @throws IllegalArgumentException if offset or length are negative * @deprecated Use {@link ByteSource#slice(int, int)} instead. This method is * scheduled for removal in Guava 18.0. */ @Deprecated public static InputSupplier<InputStream> slice( final InputSupplier<? extends InputStream> supplier, final long offset, final long length) { return asInputSupplier(asByteSource(supplier).slice(offset, length)); } /** * Joins multiple {@link InputStream} suppliers into a single supplier. * Streams returned from the supplier will contain the concatenated data from * the streams of the underlying suppliers. * * <p>Only one underlying input stream will be open at a time. Closing the * joined stream will close the open underlying stream. * * <p>Reading from the joined stream will throw a {@link NullPointerException} * if any of the suppliers are null or return null. * * @param suppliers the suppliers to concatenate * @return a supplier that will return a stream containing the concatenated * stream data * @deprecated Use {@link ByteSource#concat(Iterable)} instead. This method * is scheduled for removal in Guava 18.0. */ @Deprecated public static InputSupplier<InputStream> join( final Iterable<? extends InputSupplier<? extends InputStream>> suppliers) { checkNotNull(suppliers); Iterable<ByteSource> sources = Iterables.transform(suppliers, new Function<InputSupplier<? extends InputStream>, ByteSource>() { @Override public ByteSource apply(InputSupplier<? extends InputStream> input) { return asByteSource(input); } }); return asInputSupplier(ByteSource.concat(sources)); } /** * Varargs form of {@link #join(Iterable)}. * * @deprecated Use {@link ByteSource#concat(ByteSource[])} instead. This * method is scheduled for removal in Guava 18.0. */ @Deprecated @SuppressWarnings("unchecked") // suppress "possible heap pollution" warning in JDK7 public static InputSupplier<InputStream> join( InputSupplier<? extends InputStream>... suppliers) { return join(Arrays.asList(suppliers)); } // TODO(user): Remove these once Input/OutputSupplier methods are removed /** * Returns a view of the given {@code InputStream} supplier as a * {@code ByteSource}. * * <p>This method is a temporary method provided for easing migration from * suppliers to sources and sinks. * * @since 15.0 * @deprecated Convert all {@code InputSupplier<? extends InputStream>} * implementations to extend {@link ByteSource} or provide a method for * viewing the object as a {@code ByteSource}. This method is scheduled * for removal in Guava 18.0. */ @Deprecated public static ByteSource asByteSource( final InputSupplier<? extends InputStream> supplier) { checkNotNull(supplier); return new ByteSource() { @Override public InputStream openStream() throws IOException { return supplier.getInput(); } @Override public String toString() { return "ByteStreams.asByteSource(" + supplier + ")"; } }; } /** * Returns a view of the given {@code OutputStream} supplier as a * {@code ByteSink}. * * <p>This method is a temporary method provided for easing migration from * suppliers to sources and sinks. * * @since 15.0 * @deprecated Convert all {@code OutputSupplier<? extends OutputStream>} * implementations to extend {@link ByteSink} or provide a method for * viewing the object as a {@code ByteSink}. This method is scheduled * for removal in Guava 18.0. */ @Deprecated public static ByteSink asByteSink( final OutputSupplier<? extends OutputStream> supplier) { checkNotNull(supplier); return new ByteSink() { @Override public OutputStream openStream() throws IOException { return supplier.getOutput(); } @Override public String toString() { return "ByteStreams.asByteSink(" + supplier + ")"; } }; } @SuppressWarnings("unchecked") // used internally where known to be safe static <S extends InputStream> InputSupplier<S> asInputSupplier( final ByteSource source) { return (InputSupplier) checkNotNull(source); } @SuppressWarnings("unchecked") // used internally where known to be safe static <S extends OutputStream> OutputSupplier<S> asOutputSupplier( final ByteSink sink) { return (OutputSupplier) checkNotNull(sink); } }