带有FileRegion的Netty 4 MessageToByte编码器
我正在从原始NIO迁移到netty。我需要回复如下带有FileRegion的Netty 4 MessageToByte编码器,netty,Netty,我正在从原始NIO迁移到netty。我需要回复如下 short long long long file 我有下面的工作示例,我想知道如何将FileRegion移动到编码器中 MessageToByte编码器 @Override protected void encode(final ChannelHandlerContext ctx, final BlockResponse msg, final ByteBuf out) throws Exception { out.writeSh
short
long
long
long
file
我有下面的工作示例,我想知道如何将FileRegion移动到编码器中
MessageToByte编码器
@Override
protected void encode(final ChannelHandlerContext ctx, final BlockResponse msg,
final ByteBuf out) throws Exception {
out.writeShort(DataServerMessage.DATA_SERVER_RESPONSE_MESSAGE);
out.writeLong(msg.getBlockId());
out.writeLong(msg.getOffset());
out.writeLong(msg.getLength());
}
沟道边界HandlerAdapter
ctx.write(new BlockResponse(blockId, offset, readLength));
FileChannel channel = closer.register(file.getChannel());
ChannelFuture future = ctx.writeAndFlush(new DefaultFileRegion(channel, offset, readLength));
future.addListener(ChannelFutureListener.CLOSE);
ChannelFuture future =
ctx.writeAndFlush(new BlockResponse(blockId, offset, readLength, channel));
future.addListener(ChannelFutureListener.CLOSE);
future.addListener(new ClosableResourceChannelListener(file));
我认为,如果我在适配器中写入响应(并将文件放在那里),那么我可以在编码器中执行另一个writeAndFlush,但是编码器需要关闭它。还有别的办法吗
谢谢
编辑:
以下是有效的更新代码:
public static final class Encoder extends MessageToMessageEncoder<BlockResponse> {
private static final int HEADER_LENGTH = 2 + 4 * 3; // short, 3 longs
@Override
protected void encode(final ChannelHandlerContext ctx, final BlockResponse msg,
final List<Object> out) throws Exception {
out.add(createHeader(ctx, msg));
if (msg.getChannel() != null) {
out.add(new DefaultFileRegion(msg.getChannel(), msg.getOffset(), msg.getLength()));
}
}
private ByteBuf createHeader(final ChannelHandlerContext ctx, final BlockResponse msg) {
ByteBuf header = ctx.alloc().buffer(HEADER_LENGTH);
header.writeShort(DataServerMessage.DATA_SERVER_RESPONSE_MESSAGE);
header.writeLong(msg.getBlockId());
header.writeLong(msg.getOffset());
header.writeLong(msg.getLength());
return header;
}
}
如果还需要从编码器内触发FileRegion,则需要使用MessageToMessageEncoder,并在其中按自己的方式分配ByteBuf 所以我分配我自己的头(从ctx)并将其作为out.add(头)发送,然后我说out.add(fileRegion)?我试试这个,谢谢!