6448457: (ch) Channels.newOutputStream().write() does not write all data
Reviewed-by: iris, sherman
--- a/jdk/src/share/classes/java/nio/channels/Channels.java Mon Mar 10 23:23:48 2008 -0700
+++ b/jdk/src/share/classes/java/nio/channels/Channels.java Tue Mar 11 14:42:35 2008 +0000
@@ -66,7 +66,27 @@
private Channels() { } // No instantiation
- private static int write(WritableByteChannel ch, ByteBuffer bb)
+ /**
+ * Write all remaining bytes in buffer to the given channel.
+ * If the channel is selectable then it must be configured blocking.
+ */
+ private static void writeFullyImpl(WritableByteChannel ch, ByteBuffer bb)
+ throws IOException
+ {
+ while (bb.remaining() > 0) {
+ int n = ch.write(bb);
+ if (n <= 0)
+ throw new RuntimeException("no bytes written");
+ }
+ }
+
+ /**
+ * Write all remaining bytes in buffer to the given channel.
+ *
+ * @throws IllegalBlockingException
+ * If the channel is selectable and configured non-blocking.
+ */
+ private static void writeFully(WritableByteChannel ch, ByteBuffer bb)
throws IOException
{
if (ch instanceof SelectableChannel) {
@@ -74,14 +94,13 @@
synchronized (sc.blockingLock()) {
if (!sc.isBlocking())
throw new IllegalBlockingModeException();
- return ch.write(bb);
+ writeFullyImpl(ch, bb);
}
} else {
- return ch.write(bb);
+ writeFullyImpl(ch, bb);
}
}
-
// -- Byte streams from channels --
/**
@@ -148,7 +167,7 @@
bb.position(off);
this.bb = bb;
this.bs = bs;
- Channels.write(ch, bb);
+ Channels.writeFully(ch, bb);
}
public void close() throws IOException {
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/nio/channels/Channels/ShortWrite.java Tue Mar 11 14:42:35 2008 +0000
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2008 Sun Microsystems, Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 6448457
+ * @summary Test Channels.newOutputStream returns OutputStream that handles
+ * short writes from the underlying channel
+ */
+
+import java.io.OutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.*;
+import java.util.Random;
+
+public class ShortWrite {
+
+ static Random rand = new Random();
+ static int bytesWritten = 0;
+
+ public static void main(String[] args) throws IOException {
+
+ WritableByteChannel wbc = new WritableByteChannel() {
+ public int write(ByteBuffer src) {
+ int rem = src.remaining();
+ if (rem > 0) {
+ // short write
+ int n = rand.nextInt(rem) + 1;
+ src.position(src.position() + n);
+ bytesWritten += n;
+ return n;
+ } else {
+ return 0;
+ }
+ }
+ public void close() throws IOException {
+ throw new RuntimeException("not implemented");
+ }
+ public boolean isOpen() {
+ throw new RuntimeException("not implemented");
+ }
+ };
+
+ // wrap Channel with OutputStream
+ OutputStream out = Channels.newOutputStream(wbc);
+
+
+ // write 100, 99, 98, ... 1
+ // and check that the expected number of bytes is written
+ int expected = 0;
+ byte[] buf = new byte[100];
+ for (int i=0; i<buf.length; i++) {
+ int len = buf.length-i;
+ out.write(buf, i, len);
+ expected += len;
+ }
+ System.out.format("Bytes written: %d, expected: %d\n", bytesWritten,
+ expected);
+ if (bytesWritten != expected)
+ throw new RuntimeException("incorrect number of bytes written");
+
+ }
+}