Different hierarchy

The line of error is noted in the code below. Something I notice is if I highlight the word Customer and hold down ctrl-T it brings up the hierarchy which shows Customer - SwimCalc which is right. But if I do the same with Contractor it says Contractor - SwimCalc.Customer

public class SwimCalc extends JFrame implements ActionListener { 
    private JTabbedPane jtabbedPane;  
    private JPanel Cu开发者_高级运维stomers; 
    private JPanel Contractors;  
    private List<Customer> customers = new ArrayList<Customer>(); 

    // this fails 
    private List<Contractor> contractors = new ArrayList<Contractor>(); 

    JTextArea NameTextCustomers, ExistTextCustomers, MessageTextCustomers,  
    NameTextContractors, ExistTextContractors, MessageTextContractors; 
    JTextField lengthTextPool, widthTextPool, depthTextPool, volumeTextPool;  

    public SwimCalc() {  
        setTitle("Volume Calculator");  
        setSize (300, 200);  

        JPanel topPanel = new JPanel();  
        topPanel.setLayout( new BorderLayout() );  
        getContentPane().add( topPanel );  

        createCustomers();  
        createContractors();  

        jtabbedPane = new JTabbedPane();  
        jtabbedPane.addTab("Customer", Customers);  
        topPanel.add(jtabbedPane, BorderLayout.CENTER);  
    } 
}

The error "Contractor cannot be resolved to a type" can mean

• you never wrote class Contractor {...} anywhere in your code
• Eclipse can't compile the whole project because of some build path issues (check the Problem view for build path errors)
• You forgot to import the type Contractor