No qualifying bean of type 'com.springmvc.dao.UserDAO' available: expected at least 1 bean which qualifies as autowire candidate - spring

Question

I am getting an error as No qualifying bean of type 'com.springmvc.dao.UserDAO' available: expected at least 1 bean which qualifies as autowire candidate. for the following code, My base class is "com.springmvc"
My Controller Class is
package com.springmvc.controller;
import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import com.springmvc.dao.UserDAO;
import com.springmvc.dao.UserDAOImpl;
import com.springmvc.type.User;
#Controller
public class HomeController {
private static final Logger logger = LoggerFactory.getLogger(HomeController.class);
#Autowired
private UserDAO usrdao;
#RequestMapping(value = "/", method = RequestMethod.GET)
public String home(Locale locale, Model model) {
logger.info("Welcome home! The client locale is {}.", locale);
Date date = new Date();
DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
String formattedDate = dateFormat.format(date);
model.addAttribute("Date", formattedDate );
return "index";
}
/*
#RequestMapping(value="/login",method = RequestMethod.POST)
public String welcome(Locale locale,Model model,#ModelAttribute("LoginBean")LoginBean login){
if(login != null && login.getUserName() != "" && login.getPassword() != ""){
if(login.getUserName().equals("ajith") && login.getPassword().equals("123")){
model.addAttribute("msg","Welcome "+login.getUserName());
return "welcome";
}
else{
model.addAttribute("error","Invalid Login Details");
return "index";
}
}
else{
model.addAttribute("error","Please Enter Login Details");
return "index";
}
}
*/
#RequestMapping(value="/checkLogin",method = RequestMethod.POST)
public String CheckUser(Model model,#ModelAttribute("User")User user){
if(user != null && user.getUserName() != "" && user.getPass() != ""){
boolean isActive = usrdao.isActiveUser(user.getUserName(), user.getPass());
if(isActive){
List<User> usrLst = usrdao.ListAllUsers();
model.addAttribute("message",user.getUserName());
model.addAttribute("usrLst",usrLst);
return "home";
}
else{
model.addAttribute("error","Invalid Login Details");
return "index";
}
}
return "index";
}
#RequestMapping(value="/createUser", method = RequestMethod.GET)
public String RedirectCreateUser(Model model){
return "createUser";
}
public String createUser(Model model, #ModelAttribute User user){
usrdao.CreateOrUpdateUser(user);
return "";
}
}
UserDAO
package com.springmvc.dao;
import java.util.List;
import com.springmvc.type.User;
public interface UserDAO {
public void CreateOrUpdateUser(User user);
public void DeleteUser(int uid);
public User GetUser(int uid);
public List<User> ListAllUsers();
public boolean isActiveUser(String userName,String pass);
}
UserDAOImpl
package com.springmvc.dao;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.support.rowset.SqlRowSet;
import org.springframework.stereotype.Repository;
import com.springmvc.type.User;
#Repository("UserDAO")
public class UserDAOImpl implements UserDAO {
private JdbcTemplate jdbc;
/*
public void setJdbc(JdbcTemplate jdbc) {
this.jdbc = jdbc;
}
*/
public UserDAOImpl(DataSource DS) {
jdbc = new JdbcTemplate(DS);
}
#Override
public void CreateOrUpdateUser(User user) {
if(user.getUid() == 0){
String query = "INSERT INTO userdetails(UserName,Name,Pass) VALUES(?,?,?)";
jdbc.update(query,user.getUserName(),user.getName(),user.getPass());
}
else{
String query = "UPDATE userdetails SET UserName = ?,Name = ?,Pass = ?,isActive = ? WHERE id = ?";
jdbc.update(query, user.getUserName(),user.getName(),user.getPass(),user.getIsActive(),user.getUid());
}
}
#Override
public void DeleteUser(int uid) {
String query = "DELETE FROM userdetails WHERE id = ?";
jdbc.update(query, uid);
}
#Override
public User GetUser(int uid) {
String query = "SELECT * FROM userdetails WHERE id = ?";
return jdbc.query(query, new ResultSetExtractor<User>() {
#Override
public User extractData(ResultSet rs) throws SQLException, DataAccessException {
if(rs.next()){
User user = new User();
user.setUid(rs.getInt("id"));
user.setUserName(rs.getString("UserName"));
user.setName(rs.getString("Name"));
user.setIsActive(rs.getInt("isActive"));
return user;
}
return null;
}
});
}
#Override
public List<User> ListAllUsers() {
String query = "SELECT * FROM userdetails";
List <User> usrLst = jdbc.query(query, new RowMapper<User>() {
#Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setUid(rs.getInt("id"));
user.setUserName(rs.getString("UserName"));
user.setName(rs.getString("Name"));
user.setIsActive(rs.getInt("isActive"));
return user;
}
});
return usrLst;
}
#Override
public boolean isActiveUser(String userName, String pass) {
String query = "SELECT id FROM userdetails WHERE UserName = ? AND Pass = ? AND isActive = 1";
SqlRowSet rs = jdbc.queryForRowSet(query,userName,pass);
if(rs.next())
return true;
else
return false;
}
}
Thank You

Answer 1

UserDAOImpl do not have default constructor. either add default constructor or autowire the construction arg.

Answer 2

Spring is using a strong naming convention.
Try to use as a variable userDao as the autowired variable and use the same string in the #repository.
See this little explanation here:
https://www.tutorialspoint.com/spring/spring_beans_autowiring.htm