org.apache.rocketmq.namesrv.telnet.TelnetHandler.java Source code

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Here is the source code for org.apache.rocketmq.namesrv.telnet.TelnetHandler.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.rocketmq.namesrv.telnet;

import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

public class TelnetHandler extends SimpleChannelInboundHandler<String> {

    private static StringBuilder builder = new StringBuilder();

    static {

        builder.append("****************************************************\r\n")
                .append("Welcome . CMD for example \r\n").append("1. consumerProgress  -g zzHelloSubGroup \r\n")
                .append("2. consumerConnection  -g zzHelloSubGroup \r\n")
                .append("3. producerConnection -t zzHello -g zzHelloSendGroup \r\n")
                .append("4. topicStatus -t zzHello \r\n")
                .append("****************************************************\r\n");
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // Send greeting for a new connection.

        // ctx.write("Welcome to " + InetAddress.getLocalHost().getHostName() + "!\r\n");
        // ctx.write("It is " + new Date() + " now.\r\n");
        ctx.write(builder.toString());
        ctx.flush();
    }

    @Override
    public void channelRead0(ChannelHandlerContext ctx, String request) throws Exception {
        // Generate and write a response.
        String response;
        boolean close = false;
        if (request.isEmpty()) {
            return;
        } else if ("bye".equals(request.toLowerCase())) {
            response = "Have a good day!\r\n";
            close = true;
        } else {
            response = TelnetCommandUtil.doCmd(request);
        }

        // We do not need to write a ChannelBuffer here.
        // We know the encoder inserted at TelnetPipelineFactory will do the conversion.
        ChannelFuture future = ctx.write(response);

        // Close the connection after sending 'Have a good day!'
        // if the client has sent 'bye'.
        if (close) {
            future.addListener(ChannelFutureListener.CLOSE);
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }

}