#核心提示：

字符串构建器类型无法强制转化为字符串类型。

#原因分析：

提示很明确，发生了类型转化错误🙅‍♂️。

#解决办法：

通过 StringBuilder 类的 toString() 方法转换数据类型。

#详细提示：

ERROR [500.jsp] - java.lang.StringBuilder cannot be cast to java.lang.String java.lang.ClassCastException: java.lang.StringBuilder 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:57) at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:92) at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:280) at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:275) at org.hibernate.param.NamedParameterSpecification.bind(NamedParameterSpecification.java:66) at org.hibernate.loader.hql.QueryLoader.bindParameterValues(QueryLoader.java:608) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1870) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1831) at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1811) at org.hibernate.loader.Loader.doQuery(Loader.java:899) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341) at org.hibernate.loader.Loader.doList(Loader.java:2516) at org.hibernate.loader.Loader.doList(Loader.java:2502) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2332) at org.hibernate.loader.Loader.list(Loader.java:2327) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:490) at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355) at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:195) at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1268) at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101) at com.bluewave.common.persistence.BaseDao.find(BaseDao.java:206) at com.bluewave.common.persistence.BaseDao.find(BaseDao.java:187) at com.bluewave.modules.cms.service.FileService.queries(FileService.java:68) at com.bluewave.modules.cms.service.FileService$$FastClassBySpringCGLIB$$ea34cc66.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) at com.bluewave.modules.cms.service.FileService$$EnhancerBySpringCGLIB$$be053284.queries() at com.bluewave.modules.cms.service.FileService$$FastClassBySpringCGLIB$$ea34cc66.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) at com.bluewave.modules.cms.service.FileService$$EnhancerBySpringCGLIB$$e044626.queries() at com.bluewave.modules.ums.service.MaterialService.query(MaterialService.java:135) at com.bluewave.modules.ums.service.MaterialService$$FastClassBySpringCGLIB$$3c78756d.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) at com.bluewave.modules.ums.service.MaterialService$$EnhancerBySpringCGLIB$$ed2289f9.query() at com.bluewave.modules.ums.service.MaterialService$$FastClassBySpringCGLIB$$3c78756d.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) at com.bluewave.modules.ums.service.MaterialService$$EnhancerBySpringCGLIB$$e1b552d5.query() at com.bluewave.modules.front.BidMaterialController.query(BidMaterialController.java:137) at com.bluewave.modules.front.BidMaterialController$$FastClassBySpringCGLIB$$c057d926.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) at com.bluewave.modules.front.BidMaterialController$$EnhancerBySpringCGLIB$$93a75433.query() 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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:832) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:743) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:961) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:895) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858) at javax.servlet.http.HttpServlet.service(HttpServlet.java:529) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843) at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:197) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129) at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:151) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:142) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:88) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:491) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:83) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:764) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:72) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:398) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:1309) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1854) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:973) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:491) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63) at java.lang.Thread.run(Thread.java:750)

StringBuilder 无法转化为 String。 调用 toString() 方法就可以了。