多线程java。RuntimeException:java。lang.ClassCastException:[B不能转换为java.lang.String
在本地模式下运行storm topology时遇到此错误。
我有一个简单的程序来检查一个数字是否是素数。
我使用KafkaSpout作为源，并使用storm进行处理。
卡夫卡版本2.10-0.8.2.1
风暴版本0.9.4
动物园管理员3.4.6
下面是我检查素数的螺栓
public class PrimeNumberBolt extends BaseRichBolt
{
private static final long serialVersionUID = 1L;
private OutputCollector collector;
public void prepare( Map conf, TopologyContext context, OutputCollector collector )
{
this.collector = collector;
}
public void execute( Tuple tuple )
{
//System.out.println(tuple.getFields());
//System.out.println(tuple.getString(0));
String num = tuple.getString(0);
//int number = tuple.getInteger( 0 );
int number = Integer.parseInt(num);
//System.out.println("IN Primenumber bolt = "+number);
if( isPrime( number) )
{
System.out.println( number );
}
collector.ack( tuple );
}
public void declareOutputFields( OutputFieldsDeclarer declarer )
{
declarer.declare( new Fields( "number" ) );
}
private boolean isPrime( int n )
{
if( n == 1)
{
return false;
}
if( n == 2 || n == 3 )
{
return true;
}
// Is n an even number?
if( n % 2 == 0 )
{
return false;
}
//if not, then just check the odds
for( int i=3; i*i<=n; i+=2 )
{
if( n % i == 0)
{
return false;
}
}
return true;
}
}
错误：
**18156 [Thread-11-prime] ERROR backtype.storm.util - Async loop died!
java.lang.RuntimeException: java.lang.ClassCastException: [B cannot be cast to java.lang.String**
at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:128) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.utils.DisruptorQueue.consumeBatchWhenAvailable(DisruptorQueue.java:99) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.disruptor$consume_batch_when_available.invoke(disruptor.clj:80) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.daemon.executor$fn__3439$fn__3451$fn__3498.invoke(executor.clj:748) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.util$async_loop$fn__460.invoke(util.clj:463) ~[storm-core-0.9.4.jar:0.9.4]
at clojure.lang.AFn.run(AFn.java:24) [clojure-1.5.1.jar:na]
at java.lang.Thread.run(Thread.java:745) [na:1.7.0_79]
Caused by: java.lang.ClassCastException: [B cannot be cast to java.lang.String
**at backtype.storm.tuple.TupleImpl.getString(TupleImpl.java:112) ~[storm-core-0.9.4.jar:0.9.4]
at com.geekcap.storm_test.PrimeNumberBolt.execute(PrimeNumberBolt.java:40) ~[classes/:na]**
at backtype.storm.daemon.executor$fn__3439$tuple_action_fn__3441.invoke(executor.clj:633) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.daemon.executor$mk_task_receiver$fn__3362.invoke(executor.clj:401) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.disruptor$clojure_handler$reify__1445.onEvent(disruptor.clj:58) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:125) ~[storm-core-0.9.4.jar:0.9.4]
... 6 common frames omitted
**18158 [Thread-11-prime] ERROR backtype.storm.daemon.executor -
java.lang.RuntimeException: java.lang.ClassCastException: [B cannot be cast to java.lang.String**
at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:128) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.utils.DisruptorQueue.consumeBatchWhenAvailable(DisruptorQueue.java:99) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.disruptor$consume_batch_when_available.invoke(disruptor.clj:80) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.daemon.executor$fn__3439$fn__3451$fn__3498.invoke(executor.clj:748) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.util$async_loop$fn__460.invoke(util.clj:463) ~[storm-core-0.9.4.jar:0.9.4]
at clojure.lang.AFn.run(AFn.java:24) [clojure-1.5.1.jar:na]
at java.lang.Thread.run(Thread.java:745) [na:1.7.0_79]
**Caused by: java.lang.ClassCastException: [B cannot be cast to java.lang.String**
at backtype.storm.tuple.TupleImpl.getString(TupleImpl.java:112) ~[storm-core-0.9.4.jar:0.9.4]
at com.geekcap.storm_test.PrimeNumberBolt.execute(PrimeNumberBolt.java:40) ~[classes/:na]
at backtype.storm.daemon.executor$fn__3439$tuple_action_fn__3441.invoke(executor.clj:633) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.daemon.executor$mk_task_receiver$fn__3362.invoke(executor.clj:401) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.disruptor$clojure_handler$reify__1445.onEvent(disruptor.clj:58) ~[storm-core-0.9.4.jar:0.9.4]
at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:125) ~[storm-core-0.9.4.jar:0.9.4]
... 6 common frames omitted
18375 [Thread-11-prime] ERROR backtype.storm.util - Halting process: ("Worker died")
java.lang.RuntimeException: ("Worker died")
at backtype.storm.util$exit_process_BANG_.doInvoke(util.clj:325) [storm-core-0.9.4.jar:0.9.4]
at clojure.lang.RestFn.invoke(RestFn.java:423) [clojure-1.5.1.jar:na]
at backtype.storm.daemon.worker$fn__4693$fn__4694.invoke(worker.clj:491) [storm-core-0.9.4.jar:0.9.4]
at backtype.storm.daemon.executor$mk_executor_data$fn__3272$fn__3273.invoke(executor.clj:240) [storm-core-0.9.4.jar:0.9.4]
at backtype.storm.util$async_loop$fn__460.invoke(util.clj:473) [storm-core-0.9.4.jar:0.9.4]
at clojure.lang.AFn.run(AFn.java:24) [clojure-1.5.1.jar:na]
at java.lang.Thread.run(Thread.java:745) [na:1.7.0_79]
请建议我在代码中需要做的修改。提前谢谢
# 1 楼答案
你的卡夫卡似乎在以字节数组格式读取数据
通过设置spoutconfig，尝试使用字符串方案。计划如下