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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project 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 io.netty.example.stomp;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.stomp.DefaultStompFrame;
import io.netty.handler.codec.stomp.StompCommand;
import io.netty.handler.codec.stomp.StompFrame;
import io.netty.handler.codec.stomp.StompHeaders;

/**
 * STOMP client inbound handler implementation, which just passes received messages to listener
 */
public class StompClientHandler extends SimpleChannelInboundHandler {

    private enum ClientState {
        AUTHENTICATING,
        AUTHENTICATED,
        SUBSCRIBED,
        DISCONNECTING
    }

    private ClientState state;

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        state = ClientState.AUTHENTICATING;
        StompFrame connFrame = new DefaultStompFrame(StompCommand.CONNECT);
        connFrame.headers().set(StompHeaders.ACCEPT_VERSION, "1.2");
        connFrame.headers().set(StompHeaders.HOST, StompClient.HOST);
        connFrame.headers().set(StompHeaders.LOGIN, StompClient.LOGIN);
        connFrame.headers().set(StompHeaders.PASSCODE, StompClient.PASSCODE);
        ctx.writeAndFlush(connFrame);
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, StompFrame frame) throws Exception {
        String subscrReceiptId = "001";
        String disconReceiptId = "002";
        switch (frame.command()) {
            case CONNECTED:
                StompFrame subscribeFrame = new DefaultStompFrame(StompCommand.SUBSCRIBE);
                subscribeFrame.headers().set(StompHeaders.DESTINATION, StompClient.TOPIC);
                subscribeFrame.headers().set(StompHeaders.RECEIPT, subscrReceiptId);
                subscribeFrame.headers().set(StompHeaders.ID, "1");
                System.out.println("connected, sending subscribe frame: " + subscribeFrame);
                state = ClientState.AUTHENTICATED;
                ctx.writeAndFlush(subscribeFrame);
                break;
            case RECEIPT:
                String receiptHeader = frame.headers().getAsString(StompHeaders.RECEIPT_ID);
                if (state == ClientState.AUTHENTICATED && receiptHeader.equals(subscrReceiptId)) {
                    StompFrame msgFrame = new DefaultStompFrame(StompCommand.SEND);
                    msgFrame.headers().set(StompHeaders.DESTINATION, StompClient.TOPIC);
                    msgFrame.content().writeBytes("some payload".getBytes());
                    System.out.println("subscribed, sending message frame: " + msgFrame);
                    state = ClientState.SUBSCRIBED;
                    ctx.writeAndFlush(msgFrame);
                } else if (state == ClientState.DISCONNECTING && receiptHeader.equals(disconReceiptId)) {
                    System.out.println("disconnected");
                    ctx.close();
                } else {
                    throw new IllegalStateException("received: " + frame + ", while internal state is " + state);
                }
                break;
            case MESSAGE:
                if (state == ClientState.SUBSCRIBED) {
                    System.out.println("received frame: " + frame);
                    StompFrame disconnFrame = new DefaultStompFrame(StompCommand.DISCONNECT);
                    disconnFrame.headers().set(StompHeaders.RECEIPT, disconReceiptId);
                    System.out.println("sending disconnect frame: " + disconnFrame);
                    state = ClientState.DISCONNECTING;
                    ctx.writeAndFlush(disconnFrame);
                }
                break;
            default:
                break;
        }
    }

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