Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

setTaskIdGenerator(new DbIdGenerator()) with H2 causes NPE

See original GitHub issue

HI, I was trying to set id generator for engine configuration as suggested in Upgrade notes in 6.3.1 blog post, but code mentioned there doesn’t set the generator for task ids. When I tried to set it like this:

@Bean
    public EngineConfigurationConfigurer<SpringProcessEngineConfiguration> processEngineDbIdGeneratorConfigurer() { 
        return engineConfiguration -> engineConfiguration
                .setTaskIdGenerator(new DbIdGenerator());
    }

and with H2 being used as db it throws NPE:

2018-07-04T08:04:36.763Z ERROR org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] [traceId:,parentId:,spanId:] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException: null
	at org.flowable.engine.impl.db.DbIdGenerator.getNewBlock(DbIdGenerator.java:44) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.db.DbIdGenerator.getNextId(DbIdGenerator.java:37) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.task.service.impl.persistence.entity.TaskEntityManagerImpl.insert(TaskEntityManagerImpl.java:207) ~[flowable-task-service-6.3.1.jar:6.3.1]
	at org.flowable.task.service.impl.persistence.entity.TaskEntityManagerImpl.insert(TaskEntityManagerImpl.java:38) ~[flowable-task-service-6.3.1.jar:6.3.1]
	at org.flowable.task.service.impl.TaskServiceImpl.insertTask(TaskServiceImpl.java:98) ~[flowable-task-service-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.util.TaskHelper.insertTask(TaskHelper.java:174) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.util.TaskHelper.insertTask(TaskHelper.java:149) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.bpmn.behavior.UserTaskActivityBehavior.execute(UserTaskActivityBehavior.java:220) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.agenda.ContinueProcessOperation.executeActivityBehavior(ContinueProcessOperation.java:258) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.agenda.ContinueProcessOperation.executeSynchronous(ContinueProcessOperation.java:155) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.agenda.ContinueProcessOperation.continueThroughFlowNode(ContinueProcessOperation.java:112) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.agenda.ContinueProcessOperation.continueThroughSequenceFlow(ContinueProcessOperation.java:305) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.agenda.ContinueProcessOperation.run(ContinueProcessOperation.java:78) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.interceptor.CommandInvoker.executeOperation(CommandInvoker.java:88) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.interceptor.CommandInvoker.executeOperations(CommandInvoker.java:72) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:56) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.interceptor.BpmnOverrideContextInterceptor.execute(BpmnOverrideContextInterceptor.java:25) ~[flowable-engine-6.3.1.jar:6.3.1]
	at org.flowable.common.engine.impl.interceptor.TransactionContextInterceptor.execute(TransactionContextInterceptor.java:53) ~[flowable-engine-common-6.3.1.jar:6.3.1]
	at org.flowable.common.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:71) ~[flowable-engine-common-6.3.1.jar:6.3.1]
	at org.flowable.idm.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:49) ~[flowable-idm-spring-6.3.1.jar:6.3.1]
	at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) ~[spring-tx-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.flowable.idm.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:46) ~[flowable-idm-spring-6.3.1.jar:6.3.1]
	at org.flowable.common.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:30) ~[flowable-engine-common-6.3.1.jar:6.3.1]
	at org.flowable.common.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:56) ~[flowable-engine-common-6.3.1.jar:6.3.1]
	at org.flowable.common.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:51) ~[flowable-engine-common-6.3.1.jar:6.3.1]
	at org.flowable.engine.impl.RuntimeServiceImpl.startProcessInstanceByKey(RuntimeServiceImpl.java:105) ~[flowable-engine-6.3.1.jar:6.3.1]
...