struts2.0调用action的方法,既然说不存在-------急

Action代码:ublic class UserAction extends BaseActionSupport<User> {
@Autowired private UserManager userManager;
   private String userAccount;
   private List<User> users;
   private User model;

@Override
public String delete() throws Exception {

userManager.delInfo(userAccount);
return "reload";
} @Override
public String input() throws Exception {
prepareModel();
return "input";

} @Override
public String list() throws Exception {

System.out.println("-----------in user list------------");
users = userManager.getInfoList();
return "success";
} @Override
protected void prepareModel() throws Exception {
if(userAccount!=null){
model = userManager.getInfo(userAccount);
}else{
model = new User();
} } @Override
public String save() throws Exception {
if("".equals(model.getUserAccount())){
model.setUserAccount(null);
}
userManager.saveInfo(model);
return "reload";
} public User getModel() {
return userManager.getInfo(userAccount);
} public UserManager getUserManager() {
return userManager;
} public void setUserManager(UserManager userManager) {
this.userManager = userManager;
} public String getUserAccount() {
return userAccount;
} public void setUserAccount(String userAccount) {
this.userAccount = userAccount;
} public List<User> getUsers() {
return users;
} public void setUsers(List<User> users) {
this.users = users;
} public void setModel(User model) {
this.model = model;
}}
报的错误为：报的错误为：
java.lang.NoSuchMethodException: com.opensymphony.xwork2.ActionSupport.list() 
    java.lang.Class.getMethod(Unknown Source)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.getActionMethod(AnnotationValidationInterceptor.java:56)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:42)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
    com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:124)