How can I serialize my User class for the Firebase Database and fix this error?

Question

I\'m trying to retrieve the updated User from the dataSnapshot of the Firebase Database:

mRef.addValueEventListener(new ValueEventListener() {
        @Over         


        

Answer 1

Create a constructor with no arguments as

public User() { } as cricket mentioned and to serialize

public class User implements Serializable {

private String firstName;
private String lastName;
private String profileId;

public User() {
}

public User(String fName, String lName, String id) {
    this.firstName = fName;
    this.lastName = lName;
    this.profileId = id;

}
public String getProfileId() {
    return profileId;
}

public void setProfileId(String id) {
    this.profileId = id;
}

public String getLastName() {
    return lastName;
}

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

public String getFirstName() {
    return firstName;
}

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

}

If this didn't meet requirement note down