Netty的流水线（即 private void sendBlock( service serv, String tic, Resource block,
Update update, Info info, ResourceResolver resolver ) throws
IOException {
private Boolean _alreadyExecuted = Boolean.FALSE;
if( tic != null ) {
String tic = null;
if(!_alreadyExecuted){
getLogger().info("Before startSubmission. Currently _alreadyexecuted is " +_alreadyExecuted);
serv.getService().start( tic, info );
getLogger().info("After startSubmission, _alreadyexecuted is about to change to true. Currently _alreadyexecuted is " +_alreadyExecuted);
_alreadyExecuted = Boolean.TRUE;
getLogger().info("After startSubmission, _alreadyexecuted has been changed to true. Currently _alreadyexecuted is " +_alreadyExecuted);
}
}
}
vs ctx.foo()）之前已在StackOverflow上解释过两次：
但是，我不理解Netty关于何时使用不同方法的例子的直觉：
ctx.channel.foo()为什么在代理impl的public void channelActive(ChannelHandlerContext ctx) {
ctx.read(); // <----- HERE
}
public void channelRead(final ChannelHandlerContext ctx, Object msg) {
inboundChannel.writeAndFlush(msg).addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) {
if (future.isSuccess()) {
ctx.channel().read(); // <----- HERE
} else {
future.channel().close();
}
}
});
}
处理程序中使用'from this handler down'样式read，但在channelActive中使用'from the top'样式read }？
答案 0 :(得分：1)
使用ChannelHandlerContext.read()时，它会从ChannelPipeline所在的ChannelHandler点开始。当您使用Channel.read()时，它将从ChannelPipeline的尾部开始，因此需要在更糟糕的演员阵容中遍历整个ChannelPipeline。
此示例使用ctx.read()中的channelActive(...)而channel.read()中使用ChannelFutureListener的原因是因为ChannelFutureListener不属于ChannelHandler所以它需要从ChannelPipeline的尾部开始。另请注意，此处Channel不同。