hazelcast upgrade issue from 3.6.5 to 3.7.4

Question

Hi am upgrading hazelcast from 3.6.5 to 3.7.4 followed the instructions from hazelcast doc.

am getting an exception like: java.lang.ClassCastException: com.hazelcast.spi.impl.UnmodifiableLazyList cannot be cast to java.util.ArrayList

i just upgraded hazelcast jar do i need to do any other jar upgrade?

stacktrace follows:

2017-01-24 11:33:44 ERROR error:162 - Exception occurred in class com.rathish.test.services.authentication.impl.LocalClient the exception details are: Exception: 
[errorCode  =  504,
 errorMessage  =  Failure - Unable to retrieve entity from database
    Detailed exception trace = 
java.lang.ClassCastException: com.hazelcast.spi.impl.UnmodifiableLazyList cannot be cast to java.util.ArrayList
    at com.rathish.test.services.authentication.dao.RoleDao.getRoleByUserId(RoleDao.java:367)
    at com.rathish.test.services.authentication.impl.LocalClient.authorizeCredentials(LocalClient.java:108)
    at com.rathish.test.services.authentication.AuthValidation.validateAuthorization(AuthValidation.java:420)
    at com.rathish.test.services.authentication.AuthValidation.loginValidation(AuthValidation.java:104)
    at com.rathish.test.services.authentication.AuthenticationService.login(AuthenticationService.java:140)
    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.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:151)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:171)
    at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:152)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:104)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:387)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:331)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:103)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:297)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:254)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1028)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:372)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:381)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)
    at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:141)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.process(ProxyServlet.java:74)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.doFilter(ProxyServlet.java:291)
    at org.eclipse.equinox.servletbridge.BridgeServlet.process(BridgeServlet.java:149)
    at org.eclipse.equinox.servletbridge.BridgeFilter.doFilter(BridgeFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at com.rathish.test.web.filter.SessionValidationFilter.doFilter(SessionValidationFilter.java:105)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

Caused by: java.lang.ClassCastException: com.hazelcast.spi.impl.UnmodifiableLazyList cannot be cast to java.util.ArrayList at com.rathish.test.services.authentication.dao.RoleDao.getRoleByUserId(RoleDao.java:367) ... 56 more using along with maven

<dependency>
        <groupId>com.hazelcast</groupId>
        <artifactId>hazelcast</artifactId>
        <version>3.7.4</version>
    </dependency>
    <dependency>
        <groupId>com.hazelcast</groupId>
        <artifactId>hazelcast-client</artifactId>
        <version>3.7.4</version>
    </dependency>

Answer 1

Based entirely on your stacktrace, your RoleDao class on line 367 is something like the following (variable and method names are entirely arbitrary):

ArrayList<Baz> foo = (ArrayList<Baz>)hazelCast.findById(bar);

This presumably worked before since the actual type returned was ArrayList. However it has since changed to UnmodifiableLazyList.

Solution is to always program to interfaces, and change the code to

List<Baz> foo = hazelCast.findById(bar);

(or Collection<Baz>, depending on what the API states as the return type).

Answer 2

Are you sure it used to work in 3.6.x? I'm looking at the history in github and it always used to extend the java.util.AbstractList like this:

public class UnmodifiableLazyList<E> extends AbstractList<E> implements DataSerializable {

So it never used to extend ArrayList