channelRead0() — netty Function Reference

Architecture documentation for the channelRead0() function in FileServerHandler.java from the netty codebase.

Function java Buffer Telemetry

Entity Profile

Buffer→ Telemetry→ channelRead0() — netty Function Reference

Dependency Diagram

graph TD
  67d32c29_a386_1165_f49f_f518e28eb45b["channelRead0()"]
  bfe8a22c_48cc_17d2_2d18_ebe39ee40e8f["FileServerHandler"]
  67d32c29_a386_1165_f49f_f518e28eb45b -->|defined in| bfe8a22c_48cc_17d2_2d18_ebe39ee40e8f
  style 67d32c29_a386_1165_f49f_f518e28eb45b fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

example/src/main/java/io/netty/example/file/FileServerHandler.java lines 35–60

    @Override
    public void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        RandomAccessFile raf = null;
        long length = -1;
        try {
            raf = new RandomAccessFile(msg, "r");
            length = raf.length();
        } catch (Exception e) {
            ctx.writeAndFlush("ERR: " + e.getClass().getSimpleName() + ": " + e.getMessage() + '\n');
            return;
        } finally {
            if (length < 0 && raf != null) {
                raf.close();
            }
        }

        ctx.write("OK: " + raf.length() + '\n');
        if (ctx.pipeline().get(SslHandler.class) == null) {
            // SSL not enabled - can use zero-copy file transfer.
            ctx.write(new DefaultFileRegion(raf.getChannel(), 0, length));
        } else {
            // SSL enabled - cannot use zero-copy file transfer.
            ctx.write(new ChunkedFile(raf));
        }
        ctx.writeAndFlush("\n");
    }