struts2显示列表

Question

是把数据库中的user全部打印出来，jsp是这样的
      <s:iterator value="users">
     <s:property value="username"/>
    </s:iterator>
    
    <s:debug></s:debug>
然后Action
public String list() throws Exception{

this.users=this.userService.list();

return "list";
private List<User> users;

public List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
然后报错
java.lang.ClassCastException: com.reg.model.User cannot be cast to java.lang.String
at org.apache.struts2.components.Property.start(Property.java:139)
at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:53)
at org.apache.jsp.listSuccess_jsp._jspx_meth_s_005fproperty_005f0(listSuccess_jsp.java:182)
at org.apache.jsp.listSuccess_jsp._jspx_meth_s_005fiterator_005f0(listSuccess_jsp.java:151)
at org.apache.jsp.listSuccess_jsp._jspService(listSuccess_jsp.java:101)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:630)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:154)
at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:361)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:265)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
看意思好像是不能把User 转成String 的，是那个return "list";,有人见过这个问题吗

Answer 1

你代码好像没什么问题，你启动服务有报错么？如果有把你sturts.xml文件发来看看，如果没有，可能是少了包。

Answer 2

this.users=this.userService.list();这要看你this.userService.list()返回的是什么类型

Answer 3

你的iterator标签中的value中的值要用EL表达式去得到，或者用ognl表达式得到，你这样得到的知识一个users字符串 应该这样<s:iterator value="${users}">或者用ognl<s:iterator value="#作用域.users">

Answer 4

先输入下users，然后检查下类型

Answer 5

我测试过楼主的问题，在我的电脑上运行是没有问题的。如果是this.users=this.userService.list();这句话出错了，那应该在页面报空指针异常啊，而不是类型转换出错……

Answer 6

tomcat启动没有报错，是ssh整合的jar包，出这个问题是因为jar包的原因吗

Answer 7

this.userService.list()返回的是List<User>这个在前面的代码强转过

Answer 8

如果是用ssh做的，那估计this.users=this.userService.list();有问题……

Answer 9

怎么强转的
在daoimp里面
public List<User> find() {

List<User> users=null;
users=(List<User>)hibernateTemplate.find("from User");
return users;
}
这样的

Answer 10

第一次是没有this的，也是这样的问题
在这个list之前，做个execute(),那个就没有出错

Answer 11

怎么强转的
在daoimp里面
public List<User> find() {

List<User> users=null;
users=(List<User>)hibernateTemplate.find("from User");
return users;
}
这样的
我之前用过 根本不需要强转。
List<User> users = super.getHibernateTemplate().find("from User where fuUserName=? and fuPassword=?", new Object[]{username,password});但是这也不是出错的原因呀。。你调试不就知道了吗？

Answer 12

     <s:iterator value="users" id="item">
     <s:property value="#item.username"/>
     </s:iterator>

Answer 13

你的贴出来的代码是没有问题的,问题估计出在持久层的代码写的有问题.你把写的hql那个方法的代码贴出来看看.
其实这个方法这么写就可以了
public List<User> find() {
return (List<User>)hibernateTemplate.find(" from User");
}

Answer 14

public List<User> find() {

return  (List<User>)hibernateTemplate.find("from User");

}

Answer 15

public List<User> find() {

return  (List<User>)hibernateTemplate.find("from User");

}回复错 了

Answer 16

public List<User> find() {

return  (List<User>)hibernateTemplate.find("from User");

}回复错 了
自己代码就是这样的，我在想是不是因为是ssh组合出的问题