exceptions in java

Java Springs SEVERE Exception : javax.servlet.ServletException: Circular view path

Java Springs SEVERE  Exception : javax.servlet.ServletException: Circular view path

Exception : occurred while calling REST API in Springs

 org.apache.catalina.core.StandardWrapperValve invoke SEVERE:

Servlet.service() for servlet [Spring] in context with path [/app] threw exception

[Circular view path [events]: would dispatch back to the current handler URL [/app/service/events] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.)] with root cause javax.servlet.ServletException: Circular view path [events]: would dispatch back to the current handler URL [/app/service/events] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.) at org.springframework.web.servlet.view.InternalResourceView.prepareForRendering(InternalResourceView.java:209) at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:149) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1228) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1011) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) 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:142) 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:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$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)

Solution :

Change your controller API signature from

public EventListResponse fetchEvents() 

To

public @ResponseBody EventListResponse fetchEvents

javax.persistence.PersistenceException : NonUniqueDiscoveredSqlAliasException

javax.persistence.PersistenceException : NonUniqueDiscoveredSqlAliasException

Exception javax.persistence.PersistenceException: org.hibernate.loader.custom.NonUniqueDiscoveredSqlAliasException: Encountered a duplicated sql alias [id] during auto-discovery of a native-sql query at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1763) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1677) at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:458) $$FastClassBySpringCGLIB$$ad104aa9.invoke( <generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:52) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at 

Solution : 

Give different alias to each column you are selecting. This happens mainly due to same column names in different tables.

Something like this “select u.id as userid, adm.id as adminId from user as u, admin as adm”