不要在更新操作JPA，Eclipselink上更新密码字段

Question

我在我的Java Web项目中使用eclipselink作为持久性提供程序。我使用Bcrypt进行密码加密。

当我加载表单时，密码字段为空。但是我不知道如何在更新时忽略该字段，并使持久层不将字段验证为null。

我读了一些关于特定验证组等的东西，单独的验证器类和类似的，但我仍然在树林里，我不明白该怎么做。我将不胜感激任何帮助，以及将使我指向正确方向的资源。

管理员实体类

package com.github.cvetan.bookstore.model;

import java.io.Serializable;
import java.util.Date;
import java.util.List;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;

/**
 *
 * @author cvetan
 */
@Entity
@Table(name = "administrators")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Administrator.findAll", query = "SELECT a FROM Administrator a ORDER BY a.id DESC")
    , @NamedQuery(name = "Administrator.findById", query = "SELECT a FROM Administrator a WHERE a.id = :id")
    , @NamedQuery(name = "Administrator.findByFirstName", query = "SELECT a FROM Administrator a WHERE a.firstName = :firstName")
    , @NamedQuery(name = "Administrator.findByLastName", query = "SELECT a FROM Administrator a WHERE a.lastName = :lastName")
    , @NamedQuery(name = "Administrator.findByUsername", query = "SELECT a FROM Administrator a WHERE a.username = :username")
    , @NamedQuery(name = "Administrator.findByEmail", query = "SELECT a FROM Administrator a WHERE a.email = :email")
    , @NamedQuery(name = "Administrator.findByActive", query = "SELECT a FROM Administrator a WHERE a.active = :active")})
public class Administrator implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id")
    private Integer id;

    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 255)
    @Column(name = "first_name")
    private String firstName;

    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 255)
    @Column(name = "last_name")
    private String lastName;

    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 255)
    @Column(name = "username", unique = true)
    private String username;

    // @Pattern(regexp="[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?", message="Invalid email")//if the field contains email address consider using this annotation to enforce field validation
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 255)
    @Column(name = "email")
    private String email;

    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 255)
    @Column(name = "password")
    private String password;

    @Basic(optional = false)
    @NotNull
    @Column(name = "active")
    private boolean active;

    @Basic(optional = false)
    @NotNull
    @Column(name = "created_at")
    @Temporal(TemporalType.TIMESTAMP)
    private Date createdAt;

    @Column(name = "updated_at")
    @Temporal(TemporalType.TIMESTAMP)
    private Date updatedAt;

    @OneToMany(mappedBy = "administrator")
    private List<OrderE> orderList;

    public Administrator() {
    }

    public Administrator(Integer id) {
        this.id = id;
    }

    public Administrator(Integer id, String firstName, String lastName, String username, String email, String password, boolean active, Date createdAt) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.username = username;
        this.email = email;
        this.password = password;
        this.active = active;
        this.createdAt = createdAt;
    }

    public Integer getId() {
        return id;
    }

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

    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 getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

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

    public String getPassword() {
        return password;
    }

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

    public boolean getActive() {
        return active;
    }

    public void setActive(boolean active) {
        this.active = active;
    }

    public Date getCreatedAt() {
        return createdAt;
    }

    public void setCreatedAt(Date createdAt) {
        this.createdAt = createdAt;
    }

    public Date getUpdatedAt() {
        return updatedAt;
    }

    public void setUpdatedAt(Date updatedAt) {
        this.updatedAt = updatedAt;
    }

    @XmlTransient
    public List<OrderE> getOrderList() {
        return orderList;
    }

    public void setOrderList(List<OrderE> orderList) {
        this.orderList = orderList;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        if (!(object instanceof Administrator)) {
            return false;
        }

        Administrator other = (Administrator) object;

        return ! ((this.id == null && other.id != null) || 
                 (this.id != null && !this.id.equals(other.id)));
    }

    @Override
    public String toString() {
        return firstName + " " + lastName + "[" + username + "]";
    }

    @PrePersist
    public void setCreatedAt() {
        createdAt = new Date();
    }

    @PreUpdate
    public void setUpdatedAt() {
        updatedAt = new Date();
    }   
}