问题描述
我正在尝试从服务器向客户端发送文件，即从服务器请求的客户端。
客户端在 FileRequestProtocol 中对文件进行拼写，将其发送到服务器，服务器将文件大小添加到文件 FileRequestProtocol 并将其返回给客户端。
I'm trying to send a file, a client requested from the server, from the server to the client.The Client specefies the file in the FileRequestProtocol, sends it to the server, the server adds the file size to file FileRequestProtocol and returns it to the client.
客户端使用正确的文件大小添加新的 FileChunkReqWriteHandler 到它的管道。
The client adds a new FileChunkReqWriteHandler with the correct file size to its pipeline.
服务器用上下文和所需文件创建一个新的 ChunkedFileServerHandler 并尝试发送它，但 FileChunkReqWriteHandler 永远不会从频道读取字节。
The server creates a new ChunkedFileServerHandler with the context and the desired file and tries to send it, but the FileChunkReqWriteHandler never reads byte from the channel.
我在这里做错了什么？
日志
INFO ProtocolHeadHandler:48 - Client send ProtocolHead [version=1, jobType=FILEREQUEST]
INFO ProtocolHeadServerHandler:36 - Server receive ProtocolHead [version=1, jobType=FILEREQUEST]
INFO ProtocolHeadHandler:57 - Client ProtocolHead equals, Send Protocol FileRequestProtocol [filePath=test.jpg, fileSize=0]
INFO FileRequestServerHandler:42 - Server new FileRequest FileRequestProtocol [filePath=test.jpg, fileSize=0]
INFO FileRequestHandler:41 - Client receives FileRequestProtocol [filePath=test.jpg, fileSize=174878]
INFO ChunkedFileServerHandler:39 - New ChunkedFileServerHandler
INFO FileChunkReqWriteHandler:20 - New ChunkedFile Handler FileRequestProtocol [filePath=test.jpg, fileSize=174878]
客户
FileRequestHandler.java
FileRequestHandler.java
public class FileRequestHandler extends
SimpleChannelInboundHandler<FileRequestProtocol> {
private Logger logger = Logger.getLogger(this.getClass());
public FileRequestHandler() {
}
@Override
public void channelRead0(ChannelHandlerContext ctx, FileRequestProtocol msg) {
logger.info("Client receives " + msg);
ReferenceCountUtil.release(msg);
ctx.channel().pipeline().addLast(new FileChunkReqWriteHandler(msg));
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
logger.info("Client read complete");
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
FileChunkReqWriteHandler.java
FileChunkReqWriteHandler.java
public class FileChunkReqWriteHandler extends SimpleChannelInboundHandler<ChunkedFile> {
FileRequestProtocol fileRequestProtocol;
private Logger logger = Logger.getLogger(this.getClass());
public FileChunkReqWriteHandler(FileRequestProtocol msg) {
this.fileRequestProtocol = msg;
logger.info("New ChunkedFile Handler " + msg);
}
@Override
public void channelActive(ChannelHandlerContext ctx) {
logger.info("in channel active method");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
if (ctx.channel().isActive()) {
ctx.writeAndFlush("ERR: " +
cause.getClass().getSimpleName() + ": " +
cause.getMessage() + '\n').addListener(ChannelFutureListener.CLOSE);
}
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, ChunkedFile msg)
throws Exception {
logger.info("in channelRead0");
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
logger.info("channelRead");
ByteBuf buf = (ByteBuf) msg;
byte[] bytes = new byte[buf.readableBytes()];
buf.readBytes(bytes);
if(buf.readableBytes() >= this.fileRequestProtocol.getFileSize())
{
logger.info("received all data");
}
}
}
服务器
FileRequestServerHandler.java
FileRequestServerHandler.java
public class FileRequestServerHandler extends
SimpleChannelInboundHandler<FileRequestProtocol> {
private File f;
private Logger logger = Logger.getLogger(this.getClass());
@Override
public void channelRead0(ChannelHandlerContext ctx, FileRequestProtocol fileRequest) {
logger.info("Server new FileRequest " + fileRequest);
f = new File(fileRequest.getFilePath());
fileRequest.setFileSize(f.length());
ctx.writeAndFlush(fileRequest);
new ChunkedFileServerHandler(ctx,f);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
logger.info("Server read complete");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
ChunkedFileServerHandler.java
ChunkedFileServerHandler.java
public class ChunkedFileServerHandler extends ChunkedWriteHandler {
private Logger logger = Logger.getLogger(this.getClass());
private File file;
public ChunkedFileServerHandler(ChannelHandlerContext ctx, File file) {
this.file = file;
logger.info("New ChunkedFileServerHandler");
ChunkedFile chunkedFile;
try {
chunkedFile = new ChunkedFile(this.file);
ctx.writeAndFlush(chunkedFile);
ctx.close();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
super.channelActive(ctx);
logger.info("FILE WRITE GETS ACTIVE");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
更新
public class ServerInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast("encoder", new ObjectEncoder());
p.addLast("decoder",
new ObjectDecoder(ClassResolvers.cacheDisabled(null)));
p.addLast("protocolhead", new ProtocolHeadServerHandler());
p.addLast("filerequestserverhandler", new FileRequestServerHandler());
p.addLast("chunkedfileserver", new ChunkedFileServerHandler());
}
}
服务器启动
public void startUp()
{
bossGroup = new NioEventLoopGroup(1);
workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new ServerInitializer());
// Bind and start to accept incoming connections.
b.bind(this.port).sync().channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
推荐答案
那里我可以看到两部分：
There are 2 parts I can see:
1）你不应该在你自己的处理程序中创建一个新的处理程序，而是直接创建ChunkedFile并编写它：
1) You shouldn't create a new handler within your own handler, but directly create the ChunkedFile and write it:
public class FileRequestServerHandler extends
SimpleChannelInboundHandler<FileRequestProtocol> {
private File f;
private Logger logger = Logger.getLogger(this.getClass());
@Override
public void channelRead0(ChannelHandlerContext ctx, FileRequestProtocol fileRequest) {
logger.info("Server new FileRequest " + fileRequest);
f = new File(fileRequest.getFilePath());
fileRequest.setFileSize(f.length());
ctx.writeAndFlush(fileRequest);
// directly make your chunkedFile there instead of creating a sub handler
chunkedFile = new ChunkedFile(this.file);
ctx.writeAndFlush(chunkedFile);// need a specific handler
// Don't create such an handler: new ChunkedFileServerHandler(ctx,f);
}
2）由于你使用ChunkedInput（这里是ChunkedFile）编写，你必须拥有你的管道在你的处理程序之前是一个ChunkedWriteHandler，所以你的初始化程序看起来像：
2) Since you write using ChunkedInput (here ChunkedFile), you must have in your pipeline a ChunkedWriteHandler before your handler, so your Initializer could look like:
public class ServerInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast("encoder", new ObjectEncoder());
p.addLast("decoder",
new ObjectDecoder(ClassResolvers.cacheDisabled(null)));
p.addLast("chunkedWriteHandler", new ChunkedWriteHandler());// added
p.addLast("protocolhead", new ProtocolHeadServerHandler());
p.addLast("filerequestserverhandler", new FileRequestServerHandler());
// removed: p.addLast("chunkedfileserver", new ChunkedFileServerHandler());
}
}
ChunkedWriteHandler的位置可以更改，但总是在您自己的处理程序之前写入 ChunkedFile 。
The position of the ChunkedWriteHandler could be changed, but always before your own handler where you write the ChunkedFile.
3）最后注意事项：看看并注意你的编码器/解码器（ObjectEncoder / ObjectDecoder），因为我不能100％确定他们是否可以与文件一起编写/读取ByteBuf。
它可能有效，或者不是......
3) Final note: have a look and take care of your Encoder/Decoder (ObjectEncoder/ObjectDecoder) since I'm not 100% sure if they can collaborate with such write/read of ByteBuf from/to a file.It may work, or not...
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