How to select multiple records from table in hibernate

I am trying to get multiple values from a web page form and search the value from databate using hibernate query and retrieve the result and display it in a new page.

I need to get these text fields and even if any of the field is empty, I need to run a search query in database via controller and return set of results in a new page. I tried to store the result in array list of ArrayList but it didnt work. Could anyone please help me?

I am trying to get the text values from from web page in controller:

String lastname = request.getParameter("lastname");
String firstname = request.getParameter("firstname");
String gender = request.getParameter("gender");
String speciality = request.getParameter("speciality");
String keyword = request.getParameter("keyword");

I have Doctor's table which has all these texts fields stored. Lastname, firstname, gender, speciality. I have a class named doctor which links to the database.

@Entity 
@Table(name="DOCTOR_DETAILS")
public class Doctor {

  @Id
  @Column (nullable=false)
  private int npi;
  @Column (nullable=false)
  private String firstName;
  @Column (nullable=false)
  private String lastName;
  @Column (nullable=false)
  private String gender;
  @Column (nullable=false)
  private String speciality;
  public int getNpi() {
    return npi;
  }
  public void setNpi(int npi) {
    this.npi = npi;
  }
  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 getGender() {
    return gender;
  }
  public void setGender(String gender) {
    this.gender = gender;
  }

  public String getSpeciality() {
    return speciality;
  }
  public void setSpeciality(String speciality) {
    this.speciality = speciality;
  } 

}

I need to run a select query to retrieve the records from table. Even if any of the 4 fields are empty, the query should retrieve the records.

try {
  begin();
  ArrayList <String> cntList = new ArrayList<String>();
  Query q = getSession().createQuery("select contactName,comments from       
  Contacts where lastName = :lastName or firstName =:firstName or    
  gender=:gender or speciality = :speciality");
  q.setString("username", username);
  cntList = (ArrayList<String>) q.list();
  commit();
  return cntList;
}

Also I am not sure whether I will be able to store the result in array list if I specify it as String. Could anyone please help me?