Oracle Event Processing 12c: java errors when deploying a new OEP project

Sometimes when you create a new OEP project in JDeveloper 12c and you deploy it for the first time, you might get a list of java errors. They might look a bit like this:

Exception in thread "SpringOsgiExtenderThread-118" org.springframework.beans.Fat
alBeanException: Error in context lifecycle initialization; nested exception is
com.bea.wlevs.ede.api.ConfigurationException:
Invalid statement: "select S.properties as properties,
>>cast<<@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getOrde
rNumber() as orderNumber,
cast@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getEmail()
as email,
cast@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getTotalAmo
unt() as totalAmount
from ednInputChannel as S"
Description: Invalid call to function or constructor: cast
Cause: Probable causes are: Probable causes are: There is no symbol named com, o
r Attribute name com is invalid for STREAM or RELATION or VIEW., or Types com.or
acle.oep.FraudCheckRequest.class and com.oracle.oep.FraudCheckRequest not found
when referencing constructor or static method.., or Error while handling member
access to complex type. Constructor cast of type cast not found. or Probable cau
ses are: Probable causes are: There is no symbol named com, or Attribute name co
m is invalid for STREAM or RELATION or VIEW., or Types com.oracle.oep.FraudCheck
Request.class and com.oracle.oep.FraudCheckRequest not found when referencing co
nstructor or static method.., or Error while handling member access to complex t
ype. Constructor cast of type cast not found...
Action: Verify function or constructor for complex type exists, is not ambiguous
, and has the correct number of parameters.
at com.bea.wlevs.spring.ApplicationContextLifecycle.onApplicationEvent(A
pplicationContextLifecycle.java:146)
at org.springframework.context.event.SimpleApplicationEventMulticaster.m
ulticastEvent(SimpleApplicationEventMulticaster.java:97)
at org.springframework.context.support.AbstractApplicationContext.publis
hEvent(AbstractApplicationContext.java:324)
at org.springframework.context.support.AbstractApplicationContext.finish
Refresh(AbstractApplicationContext.java:929)
at org.springframework.osgi.context.support.AbstractOsgiBundleApplicatio
nContext.finishRefresh(AbstractOsgiBundleApplicationContext.java:235)
at org.springframework.osgi.context.support.AbstractDelegatedExecutionAp
plicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:358)
at org.springframework.osgi.util.internal.PrivilegedUtils.executeWithCus
tomTCCL(PrivilegedUtils.java:85)
at org.springframework.osgi.context.support.AbstractDelegatedExecutionAp
plicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.ja
va:320)
at org.springframework.osgi.extender.internal.dependencies.startup.Depen
dencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterAp
plicationContextExecutor.java:136)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.bea.wlevs.ede.api.ConfigurationException:
Invalid statement: "select S.properties as properties,
>>cast<<@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getOrde
rNumber() as orderNumber,
cast@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getEmail()
as email,
cast@java(S.javaContent, com.oracle.oep.FraudCheckRequest.class).getTotalAmo
unt() as totalAmount
from ednInputChannel as S"
Description: Invalid call to function or constructor: cast
Cause: Probable causes are: Probable causes are: There is no symbol named com, o
r Attribute name com is invalid for STREAM or RELATION or VIEW., or Types com.or
acle.oep.FraudCheckRequest.class and com.oracle.oep.FraudCheckRequest not found
when referencing constructor or static method.., or Error while handling member
access to complex type. Constructor cast of type cast not found. or Probable cau
ses are: Probable causes are: There is no symbol named com, or Attribute name co
m is invalid for STREAM or RELATION or VIEW., or Types com.oracle.oep.FraudCheck
Request.class and com.oracle.oep.FraudCheckRequest not found when referencing co
nstructor or static method.., or Error while handling member access to complex t
ype. Constructor cast of type cast not found...
Action: Verify function or constructor for complex type exists, is not ambiguous
, and has the correct number of parameters.
at com.oracle.cep.processor.cql.impl.CQLProcessorImpl.prepare(CQLProcess
orImpl.java:1141)
at com.oracle.cep.processor.cql.impl.CQLProcessorImpl.afterConfiguration
Active(CQLProcessorImpl.java:2788)
at com.bea.wlevs.spring.ActivationBeanPostProcessor.postProcessAfterCont
extInitialization(ActivationBeanPostProcessor.java:20)
at com.bea.wlevs.spring.DeferredBeanPostProcessor.afterConfigurationActi
ve(DeferredBeanPostProcessor.java:27)
at com.bea.wlevs.spring.ApplicationContextLifecycle.onApplicationEvent(A
pplicationContextLifecycle.java:113)
... 9 more

The solution to this is very simple.
Go back to JDeveloper, right-click on the project name and select Rebuild. Afterwards deploy again and the errors will be gone.

This has something to do with the java files not registering correctly in the project. Rebuilding the project will force those java files to be included correctly.