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Java.lang.ClassCastException: java.util.ArrayList cannot be added to java.lang.String

when I run this code, it gives me a java.lang.ClassCastException exception: java.util.ArrayList cannot be passed to java.lang.String on q1.list ();

Query q=session.createQuery("select categoryData FROM SearchHistoryEntity where userId=:u"); q.setInteger("u", userId); List<String> list1=q.list(); if(list1!=null){ Query q1=session.createQuery("FROM BookEntity where category in (:names) order by bookId"); q1.setParameter("names", list1); if(q1.list().size()>9){ q1.setFirstResult(1); q1.setMaxResults(9); } list=new ArrayList<BookEntity>(); list=q1.list();

this is a full stack:

 SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/BookStore] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.lang.String] with root cause java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.lang.String at org.hibernate.type.descriptor.java.StringTypeDescriptor.unwrap(StringTypeDescriptor.java:39) at org.hibernate.type.descriptor.sql.VarcharTypeDescriptor$1.doBind(VarcharTypeDescriptor.java:64) at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:90) at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:286) at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:281) at org.hibernate.param.NamedParameterSpecification.bind(NamedParameterSpecification.java:67) at org.hibernate.loader.hql.QueryLoader.bindParameterValues(QueryLoader.java:613) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1900) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1861) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1838) at org.hibernate.loader.Loader.doQuery(Loader.java:909) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354) at org.hibernate.loader.Loader.doList(Loader.java:2553) at org.hibernate.loader.Loader.doList(Loader.java:2539) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2369) at org.hibernate.loader.Loader.list(Loader.java:2364) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:496) at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:387) at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:231) at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1264) at org.hibernate.internal.QueryImpl.list(QueryImpl.java:103) at com.app.dao.hib.SearchHistoryDaoImpl.categoryData(SearchHistoryDaoImpl.java:150) at com.app.service.impl.SearchHistoryServiceImpl.recommend(SearchHistoryServiceImpl.java:62) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) at $Proxy37.recommend(Unknown Source) at com.app.controller.UserController.recommend(UserController.java:74) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) 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:621) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)

In the above code, I'm just trying to get a list of titles from the SearchHistory table matching a specific userId (which is a q query), and then find a list of books with these headers (q1 query), but there are some problems this doesn't work. can someone help me with this

+7
java hibernate classcastexception
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3 answers

Try to change

 q1.setParameter("names", list1);

to

 q1.setParameterList("names", list1);
+21
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try it

  List<String> list1= new ArrayList<String>(); list.add(q);
+3
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try this:

  For emaple we have pass data on server through api url and we pass parameter or body parameter value same process is here. we will pass list in parameter in this case: q1.setParameterList("names", list1);
0
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