Spring Boot MyBatis: support for java.util.Optional via config

Question

I'm using :

Spring Boot 2.1.1 (mybatis:3.4.6, mybatis-spring: 1.3.2)

In my mybatis-config.xml :

<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    <objectFactory type="com.myproject.configuration.OptionalAwareObjectFactory"/>
</configuration>

OptionalAwareObjectFactory.java is like this :

import com.google.common.collect.Iterables;
import org.apache.ibatis.reflection.factory.DefaultObjectFactory;

import java.util.List;
import java.util.Optional;

public class OptionalAwareObjectFactory extends DefaultObjectFactory {

    @SuppressWarnings("unchecked")
    @Override
    public <T> T create(Class<T> type, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {

        if (Optional.class.isAssignableFrom(type))
            return (T) Optional.ofNullable(Iterables.getOnlyElement(constructorArgs));
        else
            return super.create(type, constructorArgTypes, constructorArgs);

    }

}

In my mapper interface I have this :

Optional<User> findByUsername(String username);

But when I startup the server I get this exception :

org.springframework.security.authentication.InternalAuthenticationServiceException:

class com.myproject.entity.user.User 

cannot be cast to class java.util.Optional 

(com.myproject.entity.user.User is in unnamed module of loader 'app'; 

java.util.Optional is in module java.base of loader 'bootstrap')

How can I resolve this ?

UPDATE :

When browsing MyBatis github page I see that mybatis gets java.util.Optional support with version 3.4.7.

So I've upgraded mybatis to version 3.4.7-snapshot :

<dependencies>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.7-SNAPSHOT</version>
    </dependency>
</dependencies>
<repositories>
    <repository>
        <id>sonatype-oss-snapshots</id>
        <name>Sonatype OSS Snapshots Repository</name>
        <url>https://oss.sonatype.org/content/repositories/snapshots</url>
    </repository>
</repositories>

But the result is still the same. It seems this is not directly related to mybatis, but rather a Spring Boot classloader problem.

Update : Stacktrace :

org.springframework.security.authentication.InternalAuthenticationServiceException: class com.company.bm.entity.user.User cannot be cast to class java.util.Optional (com.company.bm.entity.user.User is in unnamed module of loader 'app'; java.util.Optional is in module java.base of loader 'bootstrap')
    at org.springframework.security.authentication.dao.DaoAuthenticationProvider.retrieveUser(DaoAuthenticationProvider.java:123)
    at org.springframework.security.authentication.dao.AbstractUserDetailsAuthenticationProvider.authenticate(AbstractUserDetailsAuthenticationProvider.java:144)
    at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:174)
    at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:199)
    at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter$AuthenticationManagerDelegator.authenticate(WebSecurityConfigurerAdapter.java:513)
    at com.company.bm.controller.GuvenlikController.giris(GuvenlikController.java:56)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320)
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at com.company.bm.security.filter.JwtAuthenticationFilter.doFilterInternal(JwtAuthenticationFilter.java:50)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:96)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:74)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:117)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:106)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassCastException: class com.company.bm.entity.user.User cannot be cast to class java.util.Optional (com.company.bm.entity.user.User is in unnamed module of loader 'app'; java.util.Optional is in module java.base of loader 'bootstrap')
    at com.sun.proxy.$Proxy112.findByUsername(Unknown Source)
    at com.company.bm.security.service.UserDetailsServiceImpl.loadUserByUsername(UserDetailsServiceImpl.java:27)
    at org.springframework.security.authentication.dao.DaoAuthenticationProvider.retrieveUser(DaoAuthenticationProvider.java:108)
    ... 107 more

Update 2:

The exception is thrown here :

public class UserDetailsServiceImpl implements UserDetailsService {
    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        Optional<User> user = userMapper.findByUsername(username);
    //...
}

So it's not directly related to Spring Security, because Spring Security is invoking UserDetailsServiceImpl.loadUserByUsername() which in turn invokes

Optional<User> user = userMapper.findByUsername(username);

I invoked userMapper.findByUsername() directly in the controller, the result is the same :

java.lang.ClassCastException: class com.company.bm.entity.user.User cannot be cast to class java.util.Optional (com.company.bm.entity.user.User is in unnamed module of loader 'app'; java.util.Optional is in module java.base of loader 'bootstrap')
    at com.sun.proxy.$Proxy112.findByUsername(Unknown Source)

Can you show the full stacktrace to show where this exception initially happens? — Roman Konoval
Added stacktrace. I get the error the moment I invoke "Optional<User> findByUsername(String username);" — Wolf359
The stacktrace you are posting is the one thrown by Spring Security. Perhaps write a test case and see if there is any more precise stacktrace can be gotten. — Ian Lim
Please see Update2. I set the root logger level to trace, but the resulting stacktrace is exactly the same (ClassCastException). Is there anything else that I could try to get a better log output ? — Wolf359
@Wolf359 After your update, are you still using your own objectFactory? — Bing Zhao

Mafei Mafei · Accepted Answer · 2020-12-28T12:31:50

Your problem is that you have added additionally 3.4.7-SNAPSHOT dependency. as the official document ,if you use mybatis-spring-boot-starter it's enough. please remove 3.4.7-SNAPSHOT dependency and try it out. it should work. because I have faced this problem.

Spring Boot MyBatis: support for java.util.Optional via config

3 Answers