From 01835fdf18d2e40b1ac13682995a119edc05d590 Mon Sep 17 00:00:00 2001 From: Xiaoyan Lin Date: Sun, 24 Jan 2016 21:41:31 -0800 Subject: [PATCH] Add LineEncoder to append a line separator automatically Motivation: See #1811 Modifications: Add LineEncoder and LineSeparator Result: The user can use LineEncoder to write a String with a line separator automatically --- .../java/io/netty/buffer/ByteBufUtil.java | 20 +++- .../main/java/io/netty/buffer/Unpooled.java | 2 +- .../handler/codec/string/LineEncoder.java | 94 +++++++++++++++++++ .../handler/codec/string/LineSeparator.java | 83 ++++++++++++++++ .../handler/codec/string/LineEncoderTest.java | 51 ++++++++++ 5 files changed, 246 insertions(+), 4 deletions(-) create mode 100644 codec/src/main/java/io/netty/handler/codec/string/LineEncoder.java create mode 100644 codec/src/main/java/io/netty/handler/codec/string/LineSeparator.java create mode 100644 codec/src/test/java/io/netty/handler/codec/string/LineEncoderTest.java diff --git a/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java b/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java index 8f049fac5a..3e231285a0 100644 --- a/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java +++ b/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java @@ -507,12 +507,26 @@ public final class ByteBufUtil { * is allocated via the {@link ByteBufAllocator}. */ public static ByteBuf encodeString(ByteBufAllocator alloc, CharBuffer src, Charset charset) { - return encodeString0(alloc, false, src, charset); + return encodeString0(alloc, false, src, charset, 0); } - static ByteBuf encodeString0(ByteBufAllocator alloc, boolean enforceHeap, CharBuffer src, Charset charset) { + /** + * Encode the given {@link CharBuffer} using the given {@link Charset} into a new {@link ByteBuf} which + * is allocated via the {@link ByteBufAllocator}. + * + * @param alloc The {@link ByteBufAllocator} to allocate {@link ByteBuf}. + * @param src The {@link CharBuffer} to encode. + * @param charset The specified {@link Charset}. + * @param extraCapacity the extra capacity to alloc except the space for decoding. + */ + public static ByteBuf encodeString(ByteBufAllocator alloc, CharBuffer src, Charset charset, int extraCapacity) { + return encodeString0(alloc, false, src, charset, extraCapacity); + } + + static ByteBuf encodeString0(ByteBufAllocator alloc, boolean enforceHeap, CharBuffer src, Charset charset, + int extraCapacity) { final CharsetEncoder encoder = CharsetUtil.encoder(charset); - int length = (int) ((double) src.remaining() * encoder.maxBytesPerChar()); + int length = (int) ((double) src.remaining() * encoder.maxBytesPerChar()) + extraCapacity; boolean release = true; final ByteBuf dst; if (enforceHeap) { diff --git a/buffer/src/main/java/io/netty/buffer/Unpooled.java b/buffer/src/main/java/io/netty/buffer/Unpooled.java index 0532c0c6a1..c2b45752ca 100644 --- a/buffer/src/main/java/io/netty/buffer/Unpooled.java +++ b/buffer/src/main/java/io/netty/buffer/Unpooled.java @@ -666,7 +666,7 @@ public final class Unpooled { } private static ByteBuf copiedBuffer(CharBuffer buffer, Charset charset) { - return ByteBufUtil.encodeString0(ALLOC, true, buffer, charset); + return ByteBufUtil.encodeString0(ALLOC, true, buffer, charset, 0); } /** diff --git a/codec/src/main/java/io/netty/handler/codec/string/LineEncoder.java b/codec/src/main/java/io/netty/handler/codec/string/LineEncoder.java new file mode 100644 index 0000000000..4b605567f5 --- /dev/null +++ b/codec/src/main/java/io/netty/handler/codec/string/LineEncoder.java @@ -0,0 +1,94 @@ +/* + * Copyright 2016 The Netty Project + * + * The Netty Project 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 io.netty.handler.codec.string; + +import io.netty.buffer.ByteBuf; +import io.netty.buffer.ByteBufUtil; +import io.netty.channel.ChannelHandler.Sharable; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelPipeline; +import io.netty.handler.codec.LineBasedFrameDecoder; +import io.netty.handler.codec.MessageToMessageEncoder; +import io.netty.util.CharsetUtil; +import io.netty.util.internal.ObjectUtil; + +import java.nio.CharBuffer; +import java.nio.charset.Charset; +import java.util.List; + +/** + * Apply a line separator to the requested {@link String} and encode it into a {@link ByteBuf}. + * A typical setup for a text-based line protocol in a TCP/IP socket would be: + * 
+ * {@link ChannelPipeline} pipeline = ...;
+ *
+ * // Decoders
+ * pipeline.addLast("frameDecoder", new {@link LineBasedFrameDecoder}(80));
+ * pipeline.addLast("stringDecoder", new {@link StringDecoder}(CharsetUtil.UTF_8));
+ *
+ * // Encoder
+ * pipeline.addLast("lineEncoder", new {@link LineEncoder}(LineSeparator.UNIX, CharsetUtil.UTF_8));
+ *
+ * and then you can use a {@link String} instead of a {@link ByteBuf} + * as a message: + * 
+ * void channelRead({@link ChannelHandlerContext} ctx, {@link String} msg) {
+ *     ch.write("Did you say '" + msg + "'?");
+ * }
+ *
+ */ +@Sharable +public class LineEncoder extends MessageToMessageEncoder { + + private final Charset charset; + private final byte[] lineSeparator; + + /** + * Creates a new instance with the current system line separator and UTF-8 charset encoding. + */ + public LineEncoder() { + this(LineSeparator.DEFAULT, CharsetUtil.UTF_8); + } + + /** + * Creates a new instance with the specified line separator and UTF-8 charset encoding. + */ + public LineEncoder(LineSeparator lineSeparator) { + this(lineSeparator, CharsetUtil.UTF_8); + } + + /** + * Creates a new instance with the specified character set. + */ + public LineEncoder(Charset charset) { + this(LineSeparator.DEFAULT, charset); + } + + /** + * Creates a new instance with the specified line separator and character set. + */ + public LineEncoder(LineSeparator lineSeparator, Charset charset) { + this.charset = ObjectUtil.checkNotNull(charset, "charset"); + this.lineSeparator = ObjectUtil.checkNotNull(lineSeparator, "lineSeparator").value().getBytes(charset); + } + + @Override + protected void encode(ChannelHandlerContext ctx, CharSequence msg, List out) throws Exception { + ByteBuf buffer = ByteBufUtil.encodeString(ctx.alloc(), CharBuffer.wrap(msg), charset, lineSeparator.length); + buffer.writeBytes(lineSeparator); + out.add(buffer); + } +} diff --git a/codec/src/main/java/io/netty/handler/codec/string/LineSeparator.java b/codec/src/main/java/io/netty/handler/codec/string/LineSeparator.java new file mode 100644 index 0000000000..d853741d11 --- /dev/null +++ b/codec/src/main/java/io/netty/handler/codec/string/LineSeparator.java @@ -0,0 +1,83 @@ +/* + * Copyright 2016 The Netty Project + * + * The Netty Project 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 io.netty.handler.codec.string; + +import io.netty.buffer.ByteBufUtil; +import io.netty.util.CharsetUtil; +import io.netty.util.internal.ObjectUtil; +import io.netty.util.internal.StringUtil; + +/** + * A class to represent line separators in different environments. + */ +public final class LineSeparator { + + /** + * The default line separator in the current system. + */ + public static final LineSeparator DEFAULT = new LineSeparator(StringUtil.NEWLINE); + + /** + * The Unix line separator(LF) + */ + public static final LineSeparator UNIX = new LineSeparator("\n"); + + /** + * The Windows line separator(CRLF) + */ + public static final LineSeparator WINDOWS = new LineSeparator("\r\n"); + + private final String value; + + /** + * Create {@link LineSeparator} with the specified {@code lineSeparator} string. + */ + public LineSeparator(String lineSeparator) { + this.value = ObjectUtil.checkNotNull(lineSeparator, "lineSeparator"); + } + + /** + * Return the string value of this line separator. + */ + public String value() { + return value; + } + + @Override + public boolean equals(Object o) { + if (this == o) { + return true; + } + if (!(o instanceof LineSeparator)) { + return false; + } + LineSeparator that = (LineSeparator) o; + return value != null ? value.equals(that.value) : that.value == null; + } + + @Override + public int hashCode() { + return value != null ? value.hashCode() : 0; + } + + /** + * Return a hex dump of the line separator in UTF-8 encoding. + */ + @Override + public String toString() { + return ByteBufUtil.hexDump(value.getBytes(CharsetUtil.UTF_8)); + } +} diff --git a/codec/src/test/java/io/netty/handler/codec/string/LineEncoderTest.java b/codec/src/test/java/io/netty/handler/codec/string/LineEncoderTest.java new file mode 100644 index 0000000000..1eb950ef48 --- /dev/null +++ b/codec/src/test/java/io/netty/handler/codec/string/LineEncoderTest.java @@ -0,0 +1,51 @@ +/* + * Copyright 2016 The Netty Project + * + * The Netty Project 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 io.netty.handler.codec.string; + +import io.netty.buffer.ByteBuf; +import io.netty.channel.embedded.EmbeddedChannel; +import io.netty.util.CharsetUtil; +import org.junit.Assert; +import org.junit.Test; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +public class LineEncoderTest { + + @Test + public void testEncode() { + testLineEncode(LineSeparator.DEFAULT, "abc"); + testLineEncode(LineSeparator.WINDOWS, "abc"); + testLineEncode(LineSeparator.UNIX, "abc"); + } + + private void testLineEncode(LineSeparator lineSeparator, String msg) { + EmbeddedChannel channel = new EmbeddedChannel(new LineEncoder(lineSeparator, CharsetUtil.UTF_8)); + assertTrue(channel.writeOutbound(msg)); + ByteBuf buf = channel.readOutbound(); + try { + byte[] data = new byte[buf.readableBytes()]; + buf.readBytes(data); + byte[] expected = (msg + lineSeparator.value()).getBytes(CharsetUtil.UTF_8); + Assert.assertArrayEquals(expected, data); + Assert.assertNull(channel.readOutbound()); + } finally { + buf.release(); + assertFalse(channel.finish()); + } + } +}