public class ClientBootstrap extends Bootstrap
Channel and makes a
connection attempt.
Options are used to configure a channel:
For the detailed list of available options, please refer toClientBootstrapb = ...; // Options for a new channel b.setOption("remoteAddress", newInetSocketAddress("example.com", 8080)); b.setOption("tcpNoDelay", true); b.setOption("receiveBufferSize", 1048576);
ChannelConfig and its sub-types.
ChannelPipeline and you can configure it
in two ways.
The recommended approach is to specify a ChannelPipelineFactory by
calling Bootstrap.setPipelineFactory(ChannelPipelineFactory).
ClientBootstrapb = ...; b.setPipelineFactory(new MyPipelineFactory()); public class MyPipelineFactory implementsChannelPipelineFactory{ publicChannelPipelinegetPipeline() throws Exception { // Create and configure a new pipeline for a new channel.ChannelPipelinep =Channels.pipeline(); p.addLast("encoder", new EncodingHandler()); p.addLast("decoder", new DecodingHandler()); p.addLast("logic", new LogicHandler()); return p; } }
The alternative approach, which works only in a certain situation, is to use the default pipeline and let the bootstrap to shallow-copy the default pipeline for each new channel:
Please note 'shallow-copy' here means that the addedClientBootstrapb = ...;ChannelPipelinep = b.getPipeline(); // Add handlers to the default pipeline. p.addLast("encoder", new EncodingHandler()); p.addLast("decoder", new DecodingHandler()); p.addLast("logic", new LogicHandler());
ChannelHandlers
are not cloned but only their references are added to the new pipeline.
Therefore, you cannot use this approach if you are going to open more than
one Channels or run a server that accepts incoming connections to
create its child channels.
ChannelsClientBootstrap is just a helper class. It neither allocates nor
manages any resources. What manages the resources is the
ChannelFactory implementation you specified in the constructor of
ClientBootstrap. Therefore, it is OK to create as many
ClientBootstrap instances as you want with the same
ChannelFactory to apply different settings for different
Channels.| 构造器和说明 |
|---|
ClientBootstrap()
Creates a new instance with no
ChannelFactory set. |
ClientBootstrap(ChannelFactory channelFactory)
Creates a new instance with the specified initial
ChannelFactory. |
| 限定符和类型 | 方法和说明 |
|---|---|
ChannelFuture |
bind(java.net.SocketAddress localAddress)
Attempts to bind a channel with the specified
localAddress. later the channel can
be connected to a remoteAddress by calling Channel.connect(SocketAddress).This method
is useful where bind and connect need to be done in separate steps. |
ChannelFuture |
connect()
Attempts a new connection with the current
"remoteAddress" and
"localAddress" option. |
ChannelFuture |
connect(java.net.SocketAddress remoteAddress)
Attempts a new connection with the specified
remoteAddress and
the current "localAddress" option. |
ChannelFuture |
connect(java.net.SocketAddress remoteAddress,
java.net.SocketAddress localAddress)
Attempts a new connection with the specified
remoteAddress and
the specified localAddress. |
getFactory, getOption, getOptions, getPipeline, getPipelineAsMap, getPipelineFactory, releaseExternalResources, setFactory, setOption, setOptions, setPipeline, setPipelineAsMap, setPipelineFactory, shutdownpublic ClientBootstrap()
ChannelFactory set.
Bootstrap.setFactory(ChannelFactory) must be called before any I/O
operation is requested.public ClientBootstrap(ChannelFactory channelFactory)
ChannelFactory.public ChannelFuture connect()
"remoteAddress" and
"localAddress" option. If the "localAddress" option is
not set, the local address of a new channel is determined automatically.
This method is similar to the following code:
ClientBootstrap b = ...;
b.connect(b.getOption("remoteAddress"), b.getOption("localAddress"));
java.lang.IllegalStateException - if "remoteAddress" option was not setjava.lang.ClassCastException - if "remoteAddress" or "localAddress" option's
value is neither a SocketAddress nor nullChannelPipelineException - if this bootstrap's pipelineFactory
failed to create a new ChannelPipelinepublic ChannelFuture connect(java.net.SocketAddress remoteAddress)
remoteAddress and
the current "localAddress" option. If the "localAddress"
option is not set, the local address of a new channel is determined
automatically. This method is identical with the following code:
ClientBootstrap b = ...;
b.connect(remoteAddress, b.getOption("localAddress"));
java.lang.ClassCastException - if "localAddress" option's value is
neither a SocketAddress nor nullChannelPipelineException - if this bootstrap's pipelineFactory
failed to create a new ChannelPipelinepublic ChannelFuture connect(java.net.SocketAddress remoteAddress, java.net.SocketAddress localAddress)
remoteAddress and
the specified localAddress. If the specified local address is
null, the local address of a new channel is determined
automatically.ChannelPipelineException - if this bootstrap's pipelineFactory
failed to create a new ChannelPipelinepublic ChannelFuture bind(java.net.SocketAddress localAddress)
localAddress. later the channel can
be connected to a remoteAddress by calling Channel.connect(SocketAddress).This method
is useful where bind and connect need to be done in separate steps.
For an instance, a user can set an attachment to the Channel via
Channel.setAttachment(Object) before beginning a connection attempt so that the user can access
the attachment once the connection is established:
ChannelFuture bindFuture = bootstrap.bind(new InetSocketAddress("192.168.0.15", 0));
Channel channel = bindFuture.getChannel();
channel.setAttachment(dataObj);
channel.connect(new InetSocketAddress("192.168.0.30", 8080));
The attachment can be accessed then in the handler like the following:
public class YourHandler extends SimpleChannelUpstreamHandler {
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
Object dataObject = ctx.getChannel().getAttachment();
}
}
ChannelPipelineException - if this bootstrap's pipelineFactory
failed to create a new ChannelPipeline