1. Inject properties
Inject properties directly:
public String userName;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
= userName;
}
@Override
public String execute() throws Exception {
// TODO Auto-generated method stub
User user = new User();
(userName);// Here you need to receive and use username.UserDAO dao = new UserDAO();
HttpServletResponse response= ();
PrintWriter out = ();
if((user))
{
("");
}
else
{
("");
}
return null;
}
Model This is a common method
I won't repeat the explanation here.
3.ModelDriven
The third method is not commonly used, you only need to understand;
The process is divided into 4 steps:
(1) Action implements ModelDriven<User> interface
(2) Add abstract methods
(3) Define and initialize a model
User user=new User();
(4) Generate setters and getters
public class CheckUserAction extends ActionSupport implements ModelDriven<User>{
private User user = new User();
public User getUser() {
return user;
}
public void setUser(User user) {
= user;
}
@Override
public String execute() throws Exception {
// TODO Auto-generated method stub
UserDAO dao = new UserDAO();
HttpServletResponse response= ();
PrintWriter out = ();
if((user))
{
("");
}
else
{
("");
}
return null;
}
@Override
public User getModel() {
// TODO Auto-generated method stub
return user;
}
Note: When using methods 1 and 3, there is no need to change the front-end and jsp code parts, because it is the userName attribute that is called directly.
Method 2 requires changing the username in jquery to,.