mapped entity saved again - issue - spring-boot

Question

whenever i am using cartRepository.save(cart) user is again inserted in user table ?(Cart is having a field User).
how not to save the user again?
Users class:
#Entity
#Table(name="users")
public class Users {
#Id
#GeneratedValue
private int id;
#Column(name="nameofuser")
//#UniqueElements
private String nameofuser;
#Column(name="password")
private String password;
#OneToOne(mappedBy="user",cascade = {CascadeType.ALL})
Cart cart;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getNameofuser() {
return nameofuser;
}
public void setNameofuser(String nameofuser) {
this.nameofuser = nameofuser;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
Cart Entity:
#Entity
#Table(name="cart")
public class Cart {
#Id
#GeneratedValue
#Column(name="id")
int id;
#OneToOne(cascade = CascadeType.ALL)
Users user;
public Users getUser() {
return user;
}
public void setUser(Users user) {
this.user = user;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
CartService class:
package com.praful.lastTry.Services;
import javax.transaction.Transactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.praful.lastTry.MenuRepository.CartRepository;
import com.praful.lastTry.Models.Cart;
import com.praful.lastTry.Models.Users;
#Service
public class CartService {
#Autowired CartRepository cartRepository;
public void bindingWithUser(Users user) {
Cart cart=new Cart();
Users user1=new Users();
cart.setUser(user1);
System.out.println(" from here==================================");
cartRepository.save(cart);
System.out.println("till here ==================================");
}
}

Answer 1

whenever i am using cartRepository.save(cart) user is again inserted in user table
Because of this code :
Users user1=new Users();
Every time you are sending a new user.
Change it to something:
public void bindingWithUser(Users user) {
Cart cart=new Cart();
Users user1= getUser();
cart.setUser(user1);
System.out.println(" from here==================================");
cartRepository.save(cart);
System.out.println("till here ==================================");
}
private Users getUser(){
//return logged in user or your logic to get user which is already there in Database
}

Answer 2

Seems like in your bindingWithUser function you are passing a User object user but inside the function, you are initializing a new User object user1 and setting it to the cart object before saving it