Convert an Object into a String

Question

Good day to everyone. I am trying to do a little coding in which a user will input his desired username. I want to check the database if the desired username of the current user is existing, so there'll be no duplication. I'm using JPA for the model and JSF for the controller and view.
Here's my Model.
@Entity
public class WebUser implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String lastName;
    private String firstName;
    private String middleName;
    private String username;
    private String password;
    public Long getId() {
        return id;
    public void setId(Long id) {
        this.id = id;
    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof WebUser)) {
            return false;
        WebUser other = (WebUser) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        return true;
    @Override
    public String toString() {
        return "web.model.WebUser[id=" + id + "]";
    public String getLastName() {
        return lastName;
    public void setLastName(String lastName) {
        this.lastName = lastName;
    public String getFirstName() {
        return firstName;
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    public String getMiddleName() {
        return middleName;
    public void setMiddleName(String middleName) {
        this.middleName = middleName;
    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;
}The controller and jsp are auto-generated from Netbeans. My question is, how will I convert the 'WebUser' object into a String so I can compare the value from input text to the value in the database?
Here is my validation method inside WebUserController.java
public void validateUsername(FacesContext facesContext, UIComponent component, Object value) throws ValidatorException {
        String newUsername = (String) value;
        System.out.println("new user name: " +newUsername);
        System.out.println("component: " +component);
        int webUserSize;
        StringBuffer sb = new StringBuffer();
        //webUsers.toString();
        if ((webUsers == null) || (webUsers != null)) {
            System.out.println("web users null");
            List<WebUser> allWebUsers = getWebUsers();
            webUserSize = allWebUsers.size();
            System.out.println("all web users: " +allWebUsers);
            System.out.println("size " +webUserSize);
            for(int i=1; i<=webUserSize; ++i) {
                sb.append(allWebUsers);
                System.out.println("username: " +sb.append(allWebUsers));
        }Honestly I'm new to java and having a hard time with this one. Hope someone can help me. Thanks a lot.
I know my code is a mess. :(

Answer 1

Thanks for the help guys! I used the "unique constraint" annotation of JPA and my problem is solved.
Here's the code:
@Entity
@Table(
    name="WebUser",
    uniqueConstraints={@UniqueConstraint(columnNames={"username"})}
public class WebUser implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String lastName;
    private String firstName;
    private String middleName;
    private String username;
    private String password;
    public Long getId() {
        return id;
    public void setId(Long id) {
        this.id = id;
    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof WebUser)) {
            return false;
        WebUser other = (WebUser) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        return true;
    @Override
    public String toString() {
        //return "web.model.WebUser[id=" + id + "]";
        return "web.model.User[username=" + username +"]";
    public String getLastName() {
        return lastName;
    public void setLastName(String lastName) {
        this.lastName = lastName;
    public String getFirstName() {
        return firstName;
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    public String getMiddleName() {
        return middleName;
    public void setMiddleName(String middleName) {
        this.middleName = middleName;
    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;
}Thanks again guys!