EmbeddedChannel

EmbeddedChannel 可以查看具体的 handler 执行顺序

package channelhandler;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import io.netty.channel.embedded.EmbeddedChannel;
import java.nio.charset.StandardCharsets;
/* Netty测试使用Channel，用于判断实际执行的handler顺序 */
public class TestEmbeddedChannel {
    public static void main(String[] args) {
        ChannelInboundHandlerAdapter h1 = new ChannelInboundHandlerAdapter(){
            @Override
            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                System.out.println("进入自定义入站handler h1");
                super.channelRead(ctx, msg);
            }
        };
        ChannelInboundHandlerAdapter h2 = new ChannelInboundHandlerAdapter(){
            @Override
            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                System.out.println("进入自定义入站handler h2");
                super.channelRead(ctx, msg);
            }
        };
        ChannelOutboundHandlerAdapter h3 = new ChannelOutboundHandlerAdapter() {
            @Override
            public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
                System.out.println("进入自定义出站handler h3");
                super.write(ctx, msg, promise);
            }
        };
        ChannelOutboundHandlerAdapter h4 = new ChannelOutboundHandlerAdapter() {
            @Override
            public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
                System.out.println("进入自定义出站handler h4");
                super.write(ctx, msg, promise);
            }
        };
        EmbeddedChannel channel = new EmbeddedChannel(h1,h2,h3,h4);
        //模拟入站操作
        channel.writeInbound(ByteBufAllocator.DEFAULT.buffer().writeBytes("hello".getBytes(StandardCharsets.UTF_8)));
        System.out.println("======");
        //模拟出站操作
        channel.writeOutbound(ByteBufAllocator.DEFAULT.buffer().writeBytes("hello".getBytes(StandardCharsets.UTF_8)));
    }
}