我正在使用Cassandra存储库从数据库中获取数据。 我使用以下查询（尽可能简单）：
public interface PersonReposiroty extends CassandraRepository<Person>
@Query("SELECT * FROM KeySp.person WHERE joinTime >= 21 ALLOW FILTERING")
public List<Person> findByTime();
}
由Java语句调用时：
List<Person> persons = repository.findByTime();
它产生一个NullPointerException。
实际上，任何应从数据库返回任何数据的查询都显示异常。
同时使用上述存储库实现的Update，Delete，Save函数可以完美运行。
请告诉我我要去哪里错了以及如何解决。 （我使用Spring Boot）
预先感谢。
我的人实体是：
@Entity
@Table(name = "person", indexes = { @Index(name="peson_index", columnList = "joinTime, category, personId") })
public class Person {
@Id
@PrimaryKeyColumn
private PersonContext context;
@Column(name = "address", columnDefinition = "LONGTEXT")
private String address;
public PersonContext getContext() {
return context;
}
public void setContext(PersonContext context) {
this.context = context;
}
public String getAddress() {
return adress;
}
public void setAddress(String address) {
this.address = address;
}
}
PersonContext.java是
@Embeddable
@PrimaryKeyClass
public class PersonContext implements Serializable {
private static final long serialVersionUID = 3L;
@NotNull
@PrimaryKeyColumn(name = "joinTime", type = PrimaryKeyType.PARTITIONED)
private long joinTime;
@NotNull
@Column(name = "category")
private String category;
@Column(name = "person_id", length = 50)
private String personId = StringUtils.EMPTY;
public long getjoinTime() {
return joinTime;
}
public void setjoinTime(long joinTime) {
this.joinTime = joinTime;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getPersonId() {
return personId;
}
public void setPersonId(String personId) {
this.personId = personId;
}
}
堆栈跟踪：
ForgivingExceptionHandler: Consumer com.User.service.CacheService$1@6e6c7b7a (amq.ctag-6VuMjQcL3vjdfed2yC78zA) method handleDelivery for channel AMQChannel(amqp://user@155.83.167.923:5672/,1) threw an exception for channel AMQChannel(amqp://guest@159.89.169.123:5672/,1)
java.lang.NullPointerException: null
at org.springframework.data.cassandra.convert.MappingCassandraConverter.readProperty(MappingCassandraConverter.java:259)
at org.springframework.data.cassandra.convert.MappingCassandraConverter$1.doWithPersistentProperty(MappingCassandraConverter.java:233)
at org.springframework.data.cassandra.convert.MappingCassandraConverter$1.doWithPersistentProperty(MappingCassandraConverter.java:229)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:330)
at org.springframework.data.cassandra.convert.MappingCassandraConverter.readProperties(MappingCassandraConverter.java:229)
at org.springframework.data.cassandra.convert.MappingCassandraConverter.readPropertiesFromRow(MappingCassandraConverter.java:223)
at org.springframework.data.cassandra.convert.MappingCassandraConverter.readEntityFromRow(MappingCassandraConverter.java:190)
at org.springframework.data.cassandra.convert.MappingCassandraConverter.readRow(MappingCassandraConverter.java:176)
at org.springframework.data.cassandra.convert.MappingCassandraConverter.read(MappingCassandraConverter.java:298)
at org.springframework.data.cassandra.core.CassandraConverterRowCallback.doWith(CassandraConverterRowCallback.java:47)
at org.springframework.data.cassandra.core.CassandraTemplate.processResultSet(CassandraTemplate.java:605)
at org.springframework.data.cassandra.core.CassandraTemplate.select(CassandraTemplate.java:594)
at org.springframework.data.cassandra.core.CassandraTemplate.select(CassandraTemplate.java:376)
at org.springframework.data.cassandra.repository.query.CassandraQueryExecution$CollectionExecution.execute(CassandraQueryExecution.java:85)
at org.springframework.data.cassandra.repository.query.CassandraQueryExecution$ResultProcessingExecution.execute(CassandraQueryExecution.java:143)
at org.springframework.data.cassandra.repository.query.AbstractCassandraQuery.execute(AbstractCassandraQuery.java:113)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:483)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:461)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:56)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:57)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy142.findByResource(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy142.findByTime()
at User.StatisticsCacheService.storeDataInternal(StatisticsCacheService.java:46)
at User.CacheService$1.handleDelivery(CacheService.java:54)
at com.rabbitmq.client.impl.ConsumerDispatcher$5.run(ConsumerDispatcher.java:149)
at com.rabbitmq.client.impl.ConsumerWorkService$WorkPoolRunnable.run(ConsumerWorkService.java:104)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
2018-10-31 13:02:48,193 ERROR [User-scheduler-2] TaskUtils$LoggingErrorHandler: Unexpected error occurred in scheduled task.
com.rabbitmq.client.AlreadyClosedException: channel is already closed due to clean channel shutdown; protocol method: #method<channel.close>(reply-code=200, reply-text=Closed due to exception from Consumer (amq.ctag-6VuMjQcL3vjdfed2yC78zA) method handleDelivery for channel AMQChannel(amqp://guest@159.89.169.123:5672/,1), class-id=0, method-id=0)
at com.rabbitmq.client.impl.AMQChannel.ensureIsOpen(AMQChannel.java:253)
at com.rabbitmq.client.impl.AMQChannel.rpc(AMQChannel.java:336)
at com.rabbitmq.client.impl.ChannelN.basicConsume(ChannelN.java:1365)
at com.rabbitmq.client.impl.recovery.AutorecoveringChannel.basicConsume(AutorecoveringChannel.java:540)
at com.rabbitmq.client.impl.recovery.AutorecoveringChannel.basicConsume(AutorecoveringChannel.java:494)
at com.rabbitmq.client.impl.recovery.AutorecoveringChannel.basicConsume(AutorecoveringChannel.java:472)
at User.service.CacheService.cacheDataInternal(CacheService.java:59)
at User.service.periodic.StatisticsCacheService.cacheData(StatisticsCacheService.java:56)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)