使用Eclipse Paho MQTT客户端通过SigV4 presignedURL连接到AWS IoT MessageBroker

Question

我正在尝试使用Eclipse Paho创建一个Java Mqtt客户端，它可以使用AwsIotWebSocketUrlSigner的getSignedUrl方法生成的SigV4预签名网址连接到亚马逊网络服务IoT MessageBroker。

连接代码如下所示。

IMqttAsyncClient client = new MqttAsyncClient(*presignedUrl*,MqttAsyncClient.generateClientId(), new MemoryPersistence());
MqttConnectOptions options = new MqttConnectOptions();
options.setCleanSession(true);
IMqttToken token = client.connect(options);
token.waitForCompletion();
client.setCallback( *callBackObject* );
client.subscribe(topic, AWSIotQos.QOS1.getValue());

我一直处于异常状态。它在上面的connect()中失败了。

MqttException (0) - java.lang.NullPointerException
    at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:38)
    at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:664)
    at java.lang.Thread.run(Thread.java:749)
Caused by: java.lang.NullPointerException
    at org.eclipse.paho.client.mqttv3.internal.websocket.WebSocketHandshake.receiveHandshakeResponse(WebSocketHandshake.java:133)
    at org.eclipse.paho.client.mqttv3.internal.websocket.WebSocketHandshake.execute(WebSocketHandshake.java:74)
    at org.eclipse.paho.client.mqttv3.internal.websocket.WebSocketSecureNetworkModule.start(WebSocketSecureNetworkModule.java:77)
    at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:650)

在Eclipse Paho中，在验证WSS握手时，这里会发生代码异常。

String connectionHeader = (String) headerMap.get(HTTP_HEADER_CONNECTION);
if (connectionHeader == null || connectionHeader.equalsIgnoreCase(HTTP_HEADER_CONNECTION_VALUE)) {
    throw new IOException("WebSocket Response header: Incorrect connection header");
}

我可以使用Javascript客户端和presignedUrl进行连接。

任何帮助/示例代码都将非常感谢。

Answer 1

在查看AWS Sdk如何使用Eclipse Paho时发现了这一点。https://github.com/aws/aws-iot-device-sdk-java/blob/647449e654096172ebfcc31d79a8c582f952219d/aws-iot-device-sdk-java/src/main/java/com/amazonaws/services/iot/client/core/AwsIotWebsocketConnection.java#L46

它正在将端口号443添加到clientEndpoint。很明显，我用的presignedUrl不是这样的。因此，我将signingUrl更改为也有端口号，并且它起作用了。