I have a connection with ORACLE database and I have class (model). I put my database information in the list when I run a.Output()-I can see data. But when I want to use my list in a method it's showing nothing!
It's my model Class: From the database, I wanna get an only first name, last name and section name
public class Customer implements Comparable<Object> {
public String ime;
public String fam;
public String oime;
Customer(){}
Customer(String n, String f, String o) {
    ime = n;
    fam=f;
    oime=o;
}
public String getIme() {
    return ime;
}
public void setIme(String ime) {
    this.ime = ime;
}
public String getFam() {
    return fam;
}
public void setFam(String fam) {
    this.fam = fam;
}
public String getOime() {
    return oime;
}
public void setOime(String o) {
    oime = o;
}
 public int compareTo(Object a) {
     if(getOime().equals(((Customer)a).getOime())) 
         return -1;
     if(this.getOime().equals(((Customer)a).getOime()))
         return 1;
     return 0;
    }
    public boolean equals(Object o) {
    return (this.getOime()==((Customer)o).getOime());
    }
    public String toString() {
    return  "Ime="+ ime+" "+fam + ", Otdel = " + oime;
    }
    }
And here I have my main class: Here I have a connection with my DB and pushing in the list all information
   public class ConnectionDatabase {
   protected  List<Customer> warehouses = new ArrayList<Customer>();
   public static Connection connectDB() {
    Connection connect = null;
    try {
        String driver = "oracle.jdbc.driver.OracleDriver";
        Class.forName(driver);       
         connect = 
     DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe", 
        "asd","pass");
    }
    catch(Exception e) {
        System.out.println(e);
    }
    return connect;
}
 ConnectionDatabase() {
    Connection connect1 = connectDB();
    PreparedStatement ps = null;
    ResultSet rs = null;
    try {
    String query = "SELECT firstname,lastname,sectionname FROM 
            staff,section";
        ps = connect1.prepareStatement(query);
        rs = ps.executeQuery();
        while(rs.next()) {
        warehouses.add(new 
   Customer(rs.getString("firstname"),
   rs.getString("lastname"),rs.getString("sectionname")));              
        }
    rs.close();
    connect1.close();
    } catch(Exception e) {e.printStackTrace();}
    }
public void Output() {
    for(int i=0; i < warehouses.size(); i++){
        System.out.println(warehouses.get(i));
    }
}
public List<Customer> typeReference(String type) {
    Customer w1 = new Customer();
    List<Customer> w2 = new ArrayList<Customer>();
    for(int i=0; i < warehouses.size(); i++) {
        w1 =  warehouses.get(i);
        if(w1.getOime().equals(otdel))
        w2.add(w1);
    }
    return w2;      
}
public static void main(String args[]) {
ConnectionDatabase a=new ConnectionDatabase();
a.typeReference("Pool");
}
    }
 
     
    