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[英]Apache Storm Bolt cannot receive any Tuple from other Bolt emit
[英]Apache Storm (Java): Bolt not receiving tuple from other Bolt
我正在使用以下拓撲使用Apache Storm:
TopologyBuilder builder = new TopologyBuilder();
builder.setSpout("socketspout", new SocketSpout(IP_HOST,PORT));
builder.setBolt("filterone", new FilterOne()).shuffleGrouping("socketspout");
builder.setBolt("filtertwo", new FilterTwo()).shuffleGrouping("filterone");
第一個螺栓的方法是(FilteOne),此類擴展了BaseRichBolt:
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("ID1","signal1"));
}
public void execute(Tuple input) {
int sig;
try {
sig=input.getInteger(1)*2;
System.out.println("Filter one.."+Integer.toString(sig));
collector.emit("ack1", new Values(input.getString(0), sig));
collector.ack(input);
} catch (Exception e) {
collector.fail(input);
}
}
第二個螺栓的方法是(FilteTwo),該類也擴展了BaseRichBolt:
public void declareOutputFields(OutputFieldsDeclarer declarer) {
}
public void execute(Tuple input) {
int sig;
try {
sig=input.getInteger(1)+1;
System.out.println("Filter two.."+Integer.toString(sig));
collector.ack(input);
} catch (Exception e) {
collector.fail(input);
}
}
當執行程序模式localcluster時,我可以看到第一個螺栓發出了元組,但是第二個螺栓從未收到該元組……
解決了該問題,修改了來自collector.emit("ack1", new Values(input.getString(0), sig));
的過濾器代碼collector.emit("ack1", new Values(input.getString(0), sig));
到collector.emit( new Values(input.getString(0), sig));
該方法的發射器的收集器可以像這樣設置:
collector.emit(input, new Values(input.getString(0), sig));
不要忘記在方法clarifyOutputFields中為此字段設置字段名稱:
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("myValue"));
}
然后,在第二個螺栓中,嘗試使用“ myValue”字段獲取值:
sig = input.getValueByField("myValue").getInteger(1)+1;
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