8066678: java.nio.channels.Channels cleanup
Reviewed-by: alanb, chegar
diff --git a/jdk/src/java.base/share/classes/java/nio/channels/Channels.java b/jdk/src/java.base/share/classes/java/nio/channels/Channels.java
index 2ab10fa..1325374 100644
--- a/jdk/src/java.base/share/classes/java/nio/channels/Channels.java
+++ b/jdk/src/java.base/share/classes/java/nio/channels/Channels.java
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -38,6 +38,7 @@
import java.nio.charset.CharsetEncoder;
import java.nio.charset.UnsupportedCharsetException;
import java.nio.channels.spi.AbstractInterruptibleChannel;
+import java.util.Objects;
import java.util.concurrent.ExecutionException;
import sun.nio.ch.ChannelInputStream;
import sun.nio.cs.StreamDecoder;
@@ -48,8 +49,8 @@
* Utility methods for channels and streams.
*
* <p> This class defines static methods that support the interoperation of the
- * stream classes of the <tt>{@link java.io}</tt> package with the channel
- * classes of this package. </p>
+ * stream classes of the {@link java.io} package with the channel classes
+ * of this package. </p>
*
*
* @author Mark Reinhold
@@ -60,12 +61,7 @@
public final class Channels {
- private Channels() { } // No instantiation
-
- private static void checkNotNull(Object o, String name) {
- if (o == null)
- throw new NullPointerException("\"" + name + "\" is null!");
- }
+ private Channels() { throw new Error("no instances"); }
/**
* Write all remaining bytes in buffer to the given channel.
@@ -91,7 +87,7 @@
throws IOException
{
if (ch instanceof SelectableChannel) {
- SelectableChannel sc = (SelectableChannel)ch;
+ SelectableChannel sc = (SelectableChannel) ch;
synchronized (sc.blockingLock()) {
if (!sc.isBlocking())
throw new IllegalBlockingModeException();
@@ -107,7 +103,7 @@
/**
* Constructs a stream that reads bytes from the given channel.
*
- * <p> The <tt>read</tt> methods of the resulting stream will throw an
+ * <p> The {@code read} methods of the resulting stream will throw an
* {@link IllegalBlockingModeException} if invoked while the underlying
* channel is in non-blocking mode. The stream will not be buffered, and
* it will not support the {@link InputStream#mark mark} or {@link
@@ -121,14 +117,14 @@
* @return A new input stream
*/
public static InputStream newInputStream(ReadableByteChannel ch) {
- checkNotNull(ch, "ch");
- return new sun.nio.ch.ChannelInputStream(ch);
+ Objects.requireNonNull(ch, "ch");
+ return new ChannelInputStream(ch);
}
/**
* Constructs a stream that writes bytes to the given channel.
*
- * <p> The <tt>write</tt> methods of the resulting stream will throw an
+ * <p> The {@code write} methods of the resulting stream will throw an
* {@link IllegalBlockingModeException} if invoked while the underlying
* channel is in non-blocking mode. The stream will not be buffered. The
* stream will be safe for access by multiple concurrent threads. Closing
@@ -139,46 +135,49 @@
*
* @return A new output stream
*/
- public static OutputStream newOutputStream(final WritableByteChannel ch) {
- checkNotNull(ch, "ch");
+ public static OutputStream newOutputStream(WritableByteChannel ch) {
+ Objects.requireNonNull(ch, "ch");
return new OutputStream() {
- private ByteBuffer bb = null;
- private byte[] bs = null; // Invoker's previous array
- private byte[] b1 = null;
+ private ByteBuffer bb;
+ private byte[] bs; // Invoker's previous array
+ private byte[] b1;
- public synchronized void write(int b) throws IOException {
- if (b1 == null)
- b1 = new byte[1];
- b1[0] = (byte)b;
- this.write(b1);
- }
+ @Override
+ public synchronized void write(int b) throws IOException {
+ if (b1 == null)
+ b1 = new byte[1];
+ b1[0] = (byte) b;
+ this.write(b1);
+ }
- public synchronized void write(byte[] bs, int off, int len)
+ @Override
+ public synchronized void write(byte[] bs, int off, int len)
throws IOException
- {
- if ((off < 0) || (off > bs.length) || (len < 0) ||
- ((off + len) > bs.length) || ((off + len) < 0)) {
- throw new IndexOutOfBoundsException();
- } else if (len == 0) {
- return;
- }
- ByteBuffer bb = ((this.bs == bs)
- ? this.bb
- : ByteBuffer.wrap(bs));
- bb.limit(Math.min(off + len, bb.capacity()));
- bb.position(off);
- this.bb = bb;
- this.bs = bs;
- Channels.writeFully(ch, bb);
+ {
+ if ((off < 0) || (off > bs.length) || (len < 0) ||
+ ((off + len) > bs.length) || ((off + len) < 0)) {
+ throw new IndexOutOfBoundsException();
+ } else if (len == 0) {
+ return;
}
+ ByteBuffer bb = ((this.bs == bs)
+ ? this.bb
+ : ByteBuffer.wrap(bs));
+ bb.limit(Math.min(off + len, bb.capacity()));
+ bb.position(off);
+ this.bb = bb;
+ this.bs = bs;
+ Channels.writeFully(ch, bb);
+ }
- public void close() throws IOException {
- ch.close();
- }
+ @Override
+ public void close() throws IOException {
+ ch.close();
+ }
- };
+ };
}
/**
@@ -196,13 +195,13 @@
*
* @since 1.7
*/
- public static InputStream newInputStream(final AsynchronousByteChannel ch) {
- checkNotNull(ch, "ch");
+ public static InputStream newInputStream(AsynchronousByteChannel ch) {
+ Objects.requireNonNull(ch, "ch");
return new InputStream() {
- private ByteBuffer bb = null;
- private byte[] bs = null; // Invoker's previous array
- private byte[] b1 = null;
+ private ByteBuffer bb;
+ private byte[] bs; // Invoker's previous array
+ private byte[] b1;
@Override
public synchronized int read() throws IOException {
@@ -216,13 +215,14 @@
@Override
public synchronized int read(byte[] bs, int off, int len)
- throws IOException
+ throws IOException
{
if ((off < 0) || (off > bs.length) || (len < 0) ||
((off + len) > bs.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
- } else if (len == 0)
+ } else if (len == 0) {
return 0;
+ }
ByteBuffer bb = ((this.bs == bs)
? this.bb
@@ -270,25 +270,25 @@
*
* @since 1.7
*/
- public static OutputStream newOutputStream(final AsynchronousByteChannel ch) {
- checkNotNull(ch, "ch");
+ public static OutputStream newOutputStream(AsynchronousByteChannel ch) {
+ Objects.requireNonNull(ch, "ch");
return new OutputStream() {
- private ByteBuffer bb = null;
- private byte[] bs = null; // Invoker's previous array
- private byte[] b1 = null;
+ private ByteBuffer bb;
+ private byte[] bs; // Invoker's previous array
+ private byte[] b1;
@Override
public synchronized void write(int b) throws IOException {
- if (b1 == null)
+ if (b1 == null)
b1 = new byte[1];
- b1[0] = (byte)b;
+ b1[0] = (byte) b;
this.write(b1);
}
@Override
public synchronized void write(byte[] bs, int off, int len)
- throws IOException
+ throws IOException
{
if ((off < 0) || (off > bs.length) || (len < 0) ||
((off + len) > bs.length) || ((off + len) < 0)) {
@@ -343,12 +343,11 @@
*
* @return A new readable byte channel
*/
- public static ReadableByteChannel newChannel(final InputStream in) {
- checkNotNull(in, "in");
+ public static ReadableByteChannel newChannel(InputStream in) {
+ Objects.requireNonNull(in, "in");
- if (in instanceof FileInputStream &&
- FileInputStream.class.equals(in.getClass())) {
- return ((FileInputStream)in).getChannel();
+ if (in.getClass() == FileInputStream.class) {
+ return ((FileInputStream) in).getChannel();
}
return new ReadableByteChannelImpl(in);
@@ -358,16 +357,16 @@
extends AbstractInterruptibleChannel // Not really interruptible
implements ReadableByteChannel
{
- InputStream in;
+ private final InputStream in;
private static final int TRANSFER_SIZE = 8192;
- private byte buf[] = new byte[0];
- private boolean open = true;
- private Object readLock = new Object();
+ private byte[] buf = new byte[0];
+ private final Object readLock = new Object();
ReadableByteChannelImpl(InputStream in) {
this.in = in;
}
+ @Override
public int read(ByteBuffer dst) throws IOException {
int len = dst.remaining();
int totalRead = 0;
@@ -399,9 +398,9 @@
}
}
+ @Override
protected void implCloseChannel() throws IOException {
in.close();
- open = false;
}
}
@@ -418,12 +417,11 @@
*
* @return A new writable byte channel
*/
- public static WritableByteChannel newChannel(final OutputStream out) {
- checkNotNull(out, "out");
+ public static WritableByteChannel newChannel(OutputStream out) {
+ Objects.requireNonNull(out, "out");
- if (out instanceof FileOutputStream &&
- FileOutputStream.class.equals(out.getClass())) {
- return ((FileOutputStream)out).getChannel();
+ if (out.getClass() == FileOutputStream.class) {
+ return ((FileOutputStream) out).getChannel();
}
return new WritableByteChannelImpl(out);
@@ -433,16 +431,16 @@
extends AbstractInterruptibleChannel // Not really interruptible
implements WritableByteChannel
{
- OutputStream out;
+ private final OutputStream out;
private static final int TRANSFER_SIZE = 8192;
- private byte buf[] = new byte[0];
- private boolean open = true;
- private Object writeLock = new Object();
+ private byte[] buf = new byte[0];
+ private final Object writeLock = new Object();
WritableByteChannelImpl(OutputStream out) {
this.out = out;
}
+ @Override
public int write(ByteBuffer src) throws IOException {
int len = src.remaining();
int totalWritten = 0;
@@ -465,9 +463,9 @@
}
}
+ @Override
protected void implCloseChannel() throws IOException {
out.close();
- open = false;
}
}
@@ -479,7 +477,7 @@
* given decoder.
*
* <p> The resulting stream will contain an internal input buffer of at
- * least <tt>minBufferCap</tt> bytes. The stream's <tt>read</tt> methods
+ * least {@code minBufferCap} bytes. The stream's {@code read} methods
* will, as needed, fill the buffer by reading bytes from the underlying
* channel; if the channel is in non-blocking mode when bytes are to be
* read then an {@link IllegalBlockingModeException} will be thrown. The
@@ -495,7 +493,7 @@
*
* @param minBufferCap
* The minimum capacity of the internal byte buffer,
- * or <tt>-1</tt> if an implementation-dependent
+ * or {@code -1} if an implementation-dependent
* default capacity is to be used
*
* @return A new reader
@@ -504,7 +502,7 @@
CharsetDecoder dec,
int minBufferCap)
{
- checkNotNull(ch, "ch");
+ Objects.requireNonNull(ch, "ch");
return StreamDecoder.forDecoder(ch, dec.reset(), minBufferCap);
}
@@ -514,16 +512,15 @@
*
* <p> An invocation of this method of the form
*
- * <blockquote><pre>
- * Channels.newReader(ch, csname)</pre></blockquote>
+ * <pre> {@code
+ * Channels.newReader(ch, csname)
+ * } </pre>
*
* behaves in exactly the same way as the expression
*
- * <blockquote><pre>
- * Channels.newReader(ch,
- * Charset.forName(csName)
- * .newDecoder(),
- * -1);</pre></blockquote>
+ * <pre> {@code
+ * Channels.newReader(ch, Charset.forName(csName).newDecoder(), -1)
+ * } </pre>
*
* @param ch
* The channel from which bytes will be read
@@ -540,7 +537,7 @@
public static Reader newReader(ReadableByteChannel ch,
String csName)
{
- checkNotNull(csName, "csName");
+ Objects.requireNonNull(csName, "csName");
return newReader(ch, Charset.forName(csName).newDecoder(), -1);
}
@@ -549,7 +546,7 @@
* writes the resulting bytes to the given channel.
*
* <p> The resulting stream will contain an internal output buffer of at
- * least <tt>minBufferCap</tt> bytes. The stream's <tt>write</tt> methods
+ * least {@code minBufferCap} bytes. The stream's {@code write} methods
* will, as needed, flush the buffer by writing bytes to the underlying
* channel; if the channel is in non-blocking mode when bytes are to be
* written then an {@link IllegalBlockingModeException} will be thrown.
@@ -564,16 +561,16 @@
*
* @param minBufferCap
* The minimum capacity of the internal byte buffer,
- * or <tt>-1</tt> if an implementation-dependent
+ * or {@code -1} if an implementation-dependent
* default capacity is to be used
*
* @return A new writer
*/
- public static Writer newWriter(final WritableByteChannel ch,
- final CharsetEncoder enc,
- final int minBufferCap)
+ public static Writer newWriter(WritableByteChannel ch,
+ CharsetEncoder enc,
+ int minBufferCap)
{
- checkNotNull(ch, "ch");
+ Objects.requireNonNull(ch, "ch");
return StreamEncoder.forEncoder(ch, enc.reset(), minBufferCap);
}
@@ -582,17 +579,15 @@
* charset and writes the resulting bytes to the given channel.
*
* <p> An invocation of this method of the form
- *
- * <blockquote><pre>
- * Channels.newWriter(ch, csname)</pre></blockquote>
- *
+ * <p>
+ * <pre> {@code
+ * Channels.newWriter(ch, csname)
+ * } </pre>
* behaves in exactly the same way as the expression
- *
- * <blockquote><pre>
- * Channels.newWriter(ch,
- * Charset.forName(csName)
- * .newEncoder(),
- * -1);</pre></blockquote>
+ * <p>
+ * <pre> {@code
+ * Channels.newWriter(ch, Charset.forName(csName).newEncoder(), -1)
+ * } </pre>
*
* @param ch
* The channel to which bytes will be written
@@ -609,7 +604,7 @@
public static Writer newWriter(WritableByteChannel ch,
String csName)
{
- checkNotNull(csName, "csName");
+ Objects.requireNonNull(csName, "csName");
return newWriter(ch, Charset.forName(csName).newEncoder(), -1);
}
}
