Java更改.jar文件显示图标

Question

我尝试更改我通过Eclipse导出的jar文件的显示icon。在网上搜索后，我找到了这段代码：

"frmPos.setIconImage( new imageIcon( getClass().getClassLoader().getResource( "PATH/TO/YourImage.png" ) ) );"

但它不起作用，它给了我这个错误＆＃34;描述资源路径位置类型 imageIcon无法解析为类型window_layout.java / PostOffice / src第150行Java问题＆＃34;。谁能告诉我我做错了什么？我是否在错误的位置放置了更改jar图标的代码？下面是我的代码示例。感谢。

import java.awt.EventQueue;


public class window_layout {

    private JFrame frmPos;
    private ArrayList<Shipment> shipment_list;
    private Shipment temp;

    private boolean international_destination_bl;
    private boolean priority_bl;
    private int domestic_counter;
    private int international_counter;
    private String shipment_type;
    private float weight;
    private int postal_code;
    private String country;
    private float domestic_total_cost;
    private float international_total_cost;
    private int shipments_counter;

    private String str_weight = "Βάρος:";
    private String text = null;

    private boolean JComboBox_bl;
    private boolean JComboBox_1_bl;
    private boolean JComboBox_2_bl;
    private boolean JComboBox_3_bl;

    private JFrame border;
    private JTextField textField;
    private JTextField textField_1;
    private JTextField textField_2;

    private JTextPane textPane_3;
    private JTextPane textPane_5;

    private JComboBox comboBox;
    private JComboBox comboBox_1;
    private JComboBox comboBox_2;
    private JComboBox comboBox_3;
    private JTextField textField_3;

    private TextArea messageBox;




    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    window_layout window = new window_layout();
                    window.frmPos.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }


    /**
     * Create the application.
     */
    public window_layout() 
    {
        initialize();

        shipment_list = new ArrayList<Shipment> ( );

        international_destination_bl = false;
        domestic_counter = 0;
        international_counter = 0;
        weight = 0;
        postal_code = 0;
        domestic_total_cost = 0;
        international_total_cost = 0;
        shipments_counter = 0;

        JComboBox_bl = false;
        JComboBox_1_bl = false;
        JComboBox_2_bl = false;
        JComboBox_3_bl = false;


    }

    //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    // Initialize the contents of the frame.

    private void initialize() 
    {
        frmPos = new JFrame();
        frmPos.setIconImage(Toolkit.getDefaultToolkit().getImage("C:\\Users\\Christos\\workspace\\PostOffice\\Envelope_64x64.png"));
        frmPos.setTitle("e - Post Office");
        frmPos.getContentPane().setBackground(new Color(255, 255, 255));
        frmPos.setBounds(100, 100, 448, 438);
        frmPos.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmPos.getContentPane().setLayout(null);

//*** CODE WHICH CHANGES THE ICON OF THE JAR FILE *** 
            frmPos.setIconImage( new imageIcon( getClass().getClassLoader().getResource( "Envelope_64x64.png" ) ) );