**OA项目——问题集

偏执的太偏执、 2022-08-21 12:53 171阅读 0赞

# **问题1:** #

Struts Problem Report
    
    Struts has detected an unhandled exception:
    Messages: 	
    node to traverse cannot be null!
    File: 	org/hibernate/hql/ast/util/NodeTraverser.java
    Line number: 	63
    Stacktraces
    java.lang.IllegalArgumentException: node to traverse cannot be null!
    
        org.hibernate.hql.ast.util.NodeTraverser.traverseDepthFirst(NodeTraverser.java:63)
        org.hibernate.hql.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:280)
        org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:182)
        org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
        org.hibernate.engine.query.HQLQueryPlan.(HQLQueryPlan.java:101)
        org.hibernate.engine.query.HQLQueryPlan.(HQLQueryPlan.java:80)
        org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:124)
        org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
        org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
        org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1770)
        cn.itcast.oa.base.BaseDaoImpl.findAll(BaseDaoImpl.java:63)
        cn.itcast.oa.service.impl.RoleServiceImpl.findAll(RoleServiceImpl.java:40)
        sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        java.lang.reflect.Method.invoke(Method.java:597)
        org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
        org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
        org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
        org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        $Proxy8.findAll(Unknown Source)
        cn.itcast.oa.view.action.RoleAction.list(RoleAction.java:36)
        sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        java.lang.reflect.Method.invoke(Method.java:597)
        com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
        com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
        com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
        com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
        org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
        com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
        com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
        com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
        com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
        com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
        org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
        org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
        org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
        org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
        org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
        org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
        org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
        org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
        org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        java.lang.Thread.run(Thread.java:619)

**Tomcat报的错如下：**

![Center][]

**问题出在这里：少了空格⊙﹏⊙b！**

public List<T> findAll() {
    		// TODO Auto-generated method stub
    		return getSession().createQuery("From" +clazz.getSimpleName())//
    				.list();
    	}

**解决如下：**

public List<T> findAll() {
    		// TODO Auto-generated method stub
    		return getSession().createQuery("From " +clazz.getSimpleName())//
    				.list();
    	}

# **问题2：** #

![Center 1][]

**解决如下：**

**1.检查注解**

@Controller
    @Scope("prototype")

**2.检查配置文件**

# **总结:** #

**在整个项目过程中,出现问题最多的就是配置文件和各种注解上,总是少写或错写.这主要还是对项目不熟悉的说,还好开发过程中心态很正,慢慢进入状态. 后面出了问题,大概也知道该去哪里找.**

**so,在开始一个项目时,整体的了解一下项目的框架和需求是必要的,这样遇到问题也能比较好解决,还可避免一些不必要的bug.**

**在开发过程中还是要细心( ⊙o⊙ )哇.**

[Center]: /images/20220724/7c574e4b1be5449c971b44c7dc485764.png
[Center 1]: /images/20220724/9efe987c0bb54f1fa7b619a48656acf3.png