我正在使用以下工作示例。这可能是“代码墙”，但是问题很简单：为什么总是调用方法channelActive？如果您不想阅读代码，也可以在此处找到示例。 Netty Server Client Pojo example
NettyClient：
public class NettyClient {
private String host;
private int port = 5000;
public NettyClient(String host) {
this.host = host;
}
public void send() throws InterruptedException {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast(new ObjectEncoder());
p.addLast(new ObjectDecoder(Integer.MAX_VALUE, ClassResolvers.cacheDisabled(null)));
p.addLast(new NettyClientHandler());
}
});
ChannelFuture future = b.connect(host, port).sync();
future.channel().closeFuture().sync();
} finally {
group.shutdownGracefully();
}
}
}
NettyClientHandler
public class NettyClientHandler extends ChannelInboundHandlerAdapter {
@Inject
private DeviceMessage deviceMessage;
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
// Send the message to JLoggerServer - contains deviceName, slider0, slider1, slider2, slider3, slider4, slider5
System.out.println("Channel active - client");
ctx.write(deviceMessage);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
// Read the response from JLoggerServer - Contains deviceName, adc0, adc1, adc2, adc3, adc4, adc5
DeviceMessage responseMessage = (DeviceMessage) msg;
deviceMessage.setAdcValues(responseMessage.getAdcValues());
System.out.println("read from server");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.close();
}
}
NettyServer
public class NettyServer extends Thread{
private Logger logger = LoggerFactory.getLogger(getClass());
private int port = 5000;
public NettyServer() {
}
@Override
public void run() {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.option(ChannelOption.SO_BACKLOG, 1024)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast(new ObjectEncoder());
p.addLast(new ObjectDecoder(Integer.MAX_VALUE, ClassResolvers.cacheDisabled(null)));
p.addLast(new NettyServerHandler());
}
});
// Bind and start to accept incoming connections.
ChannelFuture f = b.bind(port).sync(); // (7)
logger.info("server bind port:{}", port);
// Wait until the server socket is closed.
f.channel().closeFuture().sync();
} catch (InterruptedException e) {
logger.info(e.getMessage());
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
最后是NettyServerHandler。
public class NettyServerHandler extends ChannelInboundHandlerAdapter {
private Logger logger = LoggerFactory.getLogger(getClass());
@Autowired
private Map<String, SerialPort> allDevices;
/**
* This will be called when we send something from client to server and server
* will respond
*/
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
System.out.println("Read from client");
// Get message
DeviceMessage deviceMessage = (DeviceMessage) msg;
System.out.println(deviceMessage.getDevicename());
SerialPort serialPort = allDevices.get(deviceMessage.getDevicename());
if (serialPort == null)
return;
// Create TXData memory with twice of length as values array and insert its values
byte[] TXData = new byte[deviceMessage.getSliderValues().length * 2];
for (int i = 0; i < TXData.length; i += 2) {
TXData[i] = (byte) (deviceMessage.getSliderValues()[i] & 0xff);
TXData[i + 1] = (byte) ((deviceMessage.getSliderValues()[i] >> 8) & 0xff);
System.out.println("Slider" + i + ": " + deviceMessage.getSliderValues()[i]);
}
// Write to JLoggerDevice
serialPort.writeBytes(TXData, TXData.length);
// Create RXData memory with twice of length as values array and read the ADC values from JLoggerDevice
byte[] RXData = new byte[deviceMessage.getAdcValues().length * 2];
int receivedBytes = serialPort.bytesAvailable();
while (receivedBytes < RXData.length)
receivedBytes = serialPort.bytesAvailable(); // We need to have values.length * 2 bytes to pass
serialPort.readBytes(RXData, RXData.length);
// Create them to short
for (int i = 0; i < RXData.length / 2; i++) {
deviceMessage.getAdcValues()[i] = (short) ((RXData[i + 1] << 8) + (RXData[i] & 0xFF));
System.out.println("Adc" + i + ": " + deviceMessage.getAdcValues()[i]);
}
// Write back message to the client
ctx.write(deviceMessage);
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
logger.info("Channel active - server");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.error("server caught exception", cause);
ctx.close();
}
}
问题是，当我启动NettyServer时。
// Start the Netty server
try {
new NettyServer().start();
logger.info("Starting netty server");
} catch (Exception e) {
logger.info(e.getMessage());
}
当我尝试从客户端->服务器写入时，我总是得到这个作为putput。
客户端：
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
Channel active - client
和服务器端：
2019-09-25 20:43:34.688 INFO 8639 --- [ntLoopGroup-3-2] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:34.984 INFO 8639 --- [ntLoopGroup-3-3] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:35.268 INFO 8639 --- [ntLoopGroup-3-4] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:35.571 INFO 8639 --- [ntLoopGroup-3-1] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:35.855 INFO 8639 --- [ntLoopGroup-3-2] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:36.137 INFO 8639 --- [ntLoopGroup-3-3] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:36.468 INFO 8639 --- [ntLoopGroup-3-4] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:36.777 INFO 8639 --- [ntLoopGroup-3-1] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:37.072 INFO 8639 --- [ntLoopGroup-3-2] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:37.364 INFO 8639 --- [ntLoopGroup-3-3] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:37.648 INFO 8639 --- [ntLoopGroup-3-4] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:37.930 INFO 8639 --- [ntLoopGroup-3-1] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:38.214 INFO 8639 --- [ntLoopGroup-3-2] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:38.503 INFO 8639 --- [ntLoopGroup-3-3] s.d.J.netty.NettyServerHandler : Channel active - server
2019-09-25 20:43:38.797 INFO 8639 --- [ntLoopGroup-3-4] s.d.J.netty.NettyServerHandler
我们至少可以说客户端已连接到服务器。 ：）
channelActive。我怀疑您在从客户端写入服务器时创建了新连接。