Java tutorial
/* * Copyright 2012 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.base64; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandler.Sharable; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPipeline; import io.netty.handler.codec.ByteToMessageDecoder; import io.netty.handler.codec.DelimiterBasedFrameDecoder; import io.netty.handler.codec.Delimiters; import io.netty.handler.codec.MessageToMessageDecoder; import io.netty.util.internal.ObjectUtil; import java.util.List; /** * Decodes a Base64-encoded {@link ByteBuf} or US-ASCII {@link String} * into a {@link ByteBuf}. Please note that this decoder must be used * with a proper {@link ByteToMessageDecoder} such as {@link DelimiterBasedFrameDecoder} * if you are using a stream-based transport such as TCP/IP. A typical decoder * setup for TCP/IP would be: * <pre> * {@link ChannelPipeline} pipeline = ...; * * // Decoders * pipeline.addLast("frameDecoder", new {@link DelimiterBasedFrameDecoder}(80, {@link Delimiters#nulDelimiter()})); * pipeline.addLast("base64Decoder", new {@link Base64Decoder}()); * * // Encoder * pipeline.addLast("base64Encoder", new {@link Base64Encoder}()); * </pre> */ @Sharable public class Base64Decoder extends MessageToMessageDecoder<ByteBuf> { private final Base64Dialect dialect; public Base64Decoder() { this(Base64Dialect.STANDARD); } public Base64Decoder(Base64Dialect dialect) { this.dialect = ObjectUtil.checkNotNull(dialect, "dialect"); } @Override protected void decode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out) throws Exception { out.add(Base64.decode(msg, msg.readerIndex(), msg.readableBytes(), dialect)); } }