struts进行自定义的类型转换出现了报Action中空指针异常

public class UserConverter3 extends StrutsTypeConverter {       @Override    public Object convertFromString(Map context, String[] values, Class toClass) {         List<User> users = new ArrayList<User>();         for(String value:values){             System.out.println("b");             StringTokenizer st = new StringTokenizer(value,";");             User user = new User();             user.setUsername(st.nextToken());             user.setPassword(st.nextToken());             users.add(user);             }         System.out.println("a");         return users;     }       @Override    public String convertToString(Map context, Object o) {         // TODO Auto-generated method stub         return null;     }   }

public class UserAction2 extends ActionSupport {         private List<User> user;           public List<User> getUser() {             return user;         }           public void setUsers(List<User> user) {             this.user = user;         }                   @Override                  public String execute() throws Exception {             for(User  u:user){                 System.out.println(u.getUsername());                 System.out.println(u.getPassword());             }                   return SUCCESS;         } }

public void setUsers(List<User> user);
这里多了个s应该是public void setUser(List<User> user);

setUsers改成setUser后没有问题了，你重新部署下看看