Twitter Storm，为什么螺栓无法接收到喷头发送的信息

Question

I am using Twitter Storm in a project and I have a strange problem. I have a spout with the following nextTuple code:

public void nextTuple()
{
    HashMap cluster = this.databaseManager.getCluster();
    System.out.println("emitted: " + cluster);
    this.collector.emit(new Values(cluster));
}

And a bolt which is connected to this spout with the following execute:

public void execute(Tuple tuple)
{
    HashMap<String, List<String>> unigrams = (HashMap)tuple.getValueByField("unigrams");
    System.out.println("received: " + unigrams);
}

What is emitted should be the same as what is recieved right? So at first the output shows this:

emitted: {218460=[04ef110987074dc6b3e3174b9f57d980], 1702472=[04ef110987074dc6b3e3174b9f57d980]}
received: {218460=[04ef110987074dc6b3e3174b9f57d980], 1702472=[04ef110987074dc6b3e3174b9f57d980]}

(It is irreverent what the data means, the point is that it is emitted and received). But then, when the emitted is changed, the received is the same:

emitted: {13788873=[aa2ec732b5b64b25be81abe79d2176bb], 2293158=[aa2ec732b5b64b25be81abe79d2176bb], 218460=[04ef110987074dc6b3e3174b9f57d980], 1702472=[04ef110987074dc6b3e3174b9f57d980]}
received: {218460=[04ef110987074dc6b3e3174b9f57d980], 1702472=[04ef110987074dc6b3e3174b9f57d980]}

I am banging my has to why it doesn't work in the second case. Furthermore, the output is printing a lot more from the nextTuple than it is from the execute.

Any ideas why this is?

Answer 1

我发现的唯一解决方案是在发送之前将HashMap转换为字符串，然后在螺栓中转换回HashMap。