Обновление пользователя через html-форму удаляет роль пользователя в базе данных

Как следует из названия, у меня возникают трудности с моим проектом Java + Spring/Hibernate, где, когда я перехожу к обновлению и информации о сотрудниках или клиентах, он удаляет их роль из таблицы employee_roles/customer_roles в базе данных.

У меня была такая же проблема с удалением имени пользователя, однако я смог обойти это, создав скрытую форму ввода для имени пользователя на странице html.

Файлы для запуска этого проекта можно найти ниже. Если вы обнаружите, что не можете заставить его работать должным образом на Mac, это может быть связано с тем, что вам нужно будет изменить jdbc.url на просто: jdbc:mysql://localhost :3306/spring_pie_deal

https://drive.google.com/file/d/1YAdaGCQXH-tjDy8EfnV0WagcV33I8ADM/view?usp=sharing

Работник:

@Entity
@Table(name = "employee")

public class Employee {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;

@Column(name = "username")
private String userName;

@Column(name = "password")
private String password;

@Column(name = "first_name")
private String firstName;

@Column(name = "last_name")
private String lastName;

@Column(name = "email")
private String email;

@Column(name = "phone_number")
private String phoneNumber;

@Column(name = "address")
private String address;

@Column(name = "zipcode")
private String zipcode;


@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "employee_roles",
        joinColumns = @JoinColumn(name = "employee_id"),
        inverseJoinColumns = @JoinColumn(name = "role_id"))
private Collection<Role> roles;

public Employee() {
}

public Employee(String userName, String password, String firstName, String lastName, String email, String phoneNumber, String address, String zipcode) {
    this.userName = userName;
    this.password = password;
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
    this.phoneNumber = phoneNumber;
    this.address = address;
    this.zipcode = zipcode;
}

public Employee(String userName, String password, String firstName, String lastName, String email, String phoneNumber, String address, String zipcode, Collection<Role> roles) {
    this.userName = userName;
    this.password = password;
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
    this.phoneNumber = phoneNumber;
    this.address = address;
    this.zipcode = zipcode;
    this.roles = roles;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getUserName() {
    return userName;
}

public void setUserName(String userName) {
    this.userName = userName;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public String getPhoneNumber() {
    return phoneNumber;
}

public void setPhoneNumber(String phoneNumber) {
    this.phoneNumber = phoneNumber;
}

public String getAddress() {
    return address;
}

public void setAddress(String address) {
    this.address = address;
}

public String getZipcode() {
    return zipcode;
}

public void setZipcode(String zipcode) {
    this.zipcode = zipcode;
}

public Collection<Role> getRoles() {
    return roles;
}

public void setRoles(Collection<Role> roles) {
    this.roles = roles;
}


@Override
public String toString() {
    return "Employee{" +
            "id = " + id +
            ", userName='" + userName + '\'' +
            ", password='" + password + '\'' +
            ", firstName='" + firstName + '\'' +
            ", lastName='" + lastName + '\'' +
            ", email='" + email + '\'' +
            ", phoneNumber='" + phoneNumber + '\'' +
            ", address='" + address + '\'' +
            ", zipcode='" + zipcode + '\'' +
            ", roles = " + roles +
            '}';
}
}

Роль:

@Entity
@Table(name = "role")
public class Role {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;

@Column(name = "name")
private String name;

public Role() {
}

public Role(String name) {
    this.name = name;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

@Override
public String toString() {
    return "Role{" + "id = " + id + ", name='" + name + '\'' + '}';
}
}

СотрудникDAOImpl:

@Repository
public class EmployeeDaoImpl implements EmployeeDAO{

@Autowired
private SessionFactory sessionFactory;

// define getEmployee method
@Override
public Employee getEmployee(Long theId) {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // get Employee by the id
    Employee theEmployee = currentSession.get(Employee.class, theId);

    // return the employee
    return theEmployee;
}

// define saveEmployee method
@Override
public void saveEmployee(Employee theEmployee) {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // save Employee by the id
    currentSession.saveOrUpdate(theEmployee);
}

// define deleteEmployee method
@Override
public void deleteEmployee(Long theId) {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // delete Employee by id
    currentSession.delete(theId);
}

@Override
public List<Employee> getEmployees() {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // create query
    Query<Employee> theQuery =
            currentSession.createQuery("from Employee order by lastName", Employee.class);

    // apply result list to variable list
    List<Employee> theEmployees = theQuery.getResultList();

    // return the result list variable
    return theEmployees;
}

@Override
public Employee findByUserName(String userName) {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // now create query... where username(from database) matches uName(direct relationship with userName1)
    Query<Employee> theQuery = currentSession.createQuery("from Employee where username=:uName", Employee.class);
    theQuery.setParameter("uName", userName);

    Employee theEmployee = null;
    try {
        theEmployee = theQuery.getSingleResult();
    }
    catch (Exception e) {
        theEmployee =null;
    }
    return theEmployee;
}

@Override
public void save(Employee employee) {
    // get current hibernate session
    Session currentSession = sessionFactory.getCurrentSession();

    // create or save user
    currentSession.saveOrUpdate(employee);
}


}

Сотрудник-form.jsp:

<%@ taglib prefix = "form" uri = "http://www.springframework.org/tags/form" %>
<%@ taglib prefix = "security" uri = "http://www.springframework.org/security/tags" %>

<!DOCTYPE html>
<html>

<head>
<title>Update Employee</title>

<link type = "text/css"
      rel = "stylesheet"
      href = "${pageContext.request.contextPath}/resources/css/style.css">

<link type = "text/css"
      rel = "stylesheet"
      href = "${pageContext.request.contextPath}/resources/css/add-customer-style.css">
</head>

<body>

<div id = "wrapper">
<div id = "header">
    <h2>ERM - Employee Relationship Manager</h2>
</div>
</div>

<div id = "container">
<h3>Update Employee</h3>

<form:form action = "saveEmployee"
           modelAttribute = "employee">

    <!-- need to associate this data with a employee id -->
    <form:hidden path = "id" />

    <table>
        <tbody>

        <tr>
            <td><form:input type = "hidden" path = "userName" /></td>

        </tr>

        <tr>
            <td><form:input type = "hidden" path = "password" /></td>
        </tr>
        <tr>
            <td><label>First name:</label></td>
            <td><form:input path = "firstName" /></td>
        </tr>

        <tr>
            <td><label>Last name:</label></td>
            <td><form:input path = "lastName" /></td>
        </tr>

        <tr>
            <td><label>Email:</label></td>
            <td><form:input path = "email" /></td>
        </tr>

        <tr>
            <td><label>Phone Number:</label></td>
            <td><form:input path = "phoneNumber" /></td>
        </tr>

        <tr>
            <td><label>Address:</label></td>
            <td><form:input path = "address" /></td>
        </tr>

        <tr>
            <td><label>Zip Code:</label></td>
            <td><form:input path = "zipcode" /></td>
        </tr>

        <tr>
            <td><label></label></td>
            <td><input type = "submit" value = "Save" class = "save" /></td>
        </tr>


        </tbody>
    </table>


</form:form>

<div style = "clear; both;"></div>

<!-- Add a logout button -->
<form:form action = "${pageContext.request.contextPath}/logout"
           method = "POST">

    <input type = "submit" value = "Logout" />

</form:form>

<p>
    <a href = "${pageContext.request.contextPath}/customer/list">Back to List</a>
</p>

</div>

</body>

</html>