注意:
Bolt1 包含前三个质数(2,3,5)的列表。
Bolt2 包含后三组质数(7,11,13)的列表。
在 Bolt3 中，它只是检查数字是否为素数。
从第一个 bolt 开始，我可以从 spout 类调用 Fail()，但从第二个 bolt 开始，我无法从 spout 类调用 Fail()。
拓扑类:
......
TopologyBuilder builder = new TopologyBuilder();
builder.setSpout("spout", new SpoutClass(), 1);
builder.setBolt("bolt1", new Bolt1(), 1).shuffleGrouping("spout");
builder.setBolt("bolt2", new Bolt2(), 1).shuffleGrouping("bolt1");
builder.setBolt("bolt3", new Bolt3(), 1).shuffleGrouping("bolt2");
Spout 类:
SpoutClass implements IRichSpout{
private SpoutOutputCollector collector;
private TopologyContext context;
public void open(@SuppressWarnings("rawtypes") Map conf, TopologyContext context, SpoutOutputCollector collector) {
this.context = context;
this.collector = collector;
}
public void nextTuple() {
try {
//messageQueue is blocking queue which contains data
String msg = messageQueue.take();
String ackId = msg;
this.collector.emit(new Values(msg), ackId);
}catch (Exception e) {
e.printStackTrace();
}
}
public void ack(Object msgId) {
System.out.println("Acknowledges that this tuple has been processed ........... " + msgId);
}
public void fail(Object msgId) {
System.out.println("FAILED To Process Message :-" + msgId);
}
}
Bolt1 类:
public class Bolt1 extends BaseRichBolt {
private OutputCollector collector;
ArrayList<Integer> firstthreePrime = new ArrayList<Integer>();
firstthreePrime.add(2);
firstthreePrime.add(3);
firstthreePrime.add(5);
public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
this.collector = collector;
}
public void execute(Tuple tuple) {
String message = (String) tuple.getValueByField("msg");
System.out.println("Received " + message + " in Bolt1.");
Integer number = Integer.valueOf(message);
if (check this number contains bolt1 or not) {
//if number is contains
System.out.println(" Number is prime ............." + number + " and Throw from Bolt1");
this.collector.fail(tuple);
} else {
collector.emit(new Values(message));
collector.ack(tuple);
}
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("msg"));
}
}
Bolt2 类:
public class Bolt2 extends BaseRichBolt {
private OutputCollector collector;
ArrayList<Integer> secondthreePrime = new ArrayList<Integer>();
secondthreePrime.add(7);
secondthreePrime.add(11);
secondthreePrime.add(13);
public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
this.collector = collector;
}
public void execute(Tuple tuple) {
String message = (String) tuple.getValueByField("msg");
System.out.println("Received " + message + " in Bolt2.");
Integer number = Integer.valueOf(message);
if (check this number contains bolt2 or not) {
//if number is contains
System.out.println(" Number is prime ............." + number + " and Throw from Bolt2");
this.collector.fail(tuple);
} else {
collector.emit(new Values(message));
collector.ack(tuple);
}
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("msg"));
}
}
Bolt3 类:
public class Bolt3 extends BaseRichBolt {
private OutputCollector collector;
public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
this.collector = collector;
}
public void execute(Tuple tuple) {
String message = (String) tuple.getValueByField("msg");
System.out.println("Received " + message + " in Bolt3.");
Integer number = Integer.valueOf(message);
if (check this number is prime or not) {
//if number is prime
System.out.println(" Number is prime ............." + number + " and Throw from Bolt3");
this.collector.fail(tuple);
} else {
collector.emit(new Values(message));
collector.ack(tuple);
}
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
}
}
最佳答案
既然您使用的是 BaseRichBolt，您不想锚定传出元组吗？
_collector.emit(tuple, new Values(message));
如果你不锚定它们，那么它们就没有到来自 spout 的元组的链接。查看文档:Guaranteeing Message Processing
关于java - 我在 spout 类中的失败方法仅适用于第一个 bolt ，从第二个 bolt 开始它不起作用。，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45138439/