Java方法调用预期

increase.addActionListener(incListener());
decrease.addActionListener(decListener());

继续显示错误’预期方法调用’.
我不知道该怎么做才能解决这个问题.
任何帮助将不胜感激
谢谢

注意：完整代码附在下面.

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Main extends JDialog {
public JPanel contentPane;
public JButton decrease;
public JButton increase;
public JLabel label;

public int number;

public Main() {
    setContentPane(contentPane);
    setModal(true);

    increase = new JButton();
    decrease = new JButton();
    increase.addActionListener(incListener());
    decrease.addActionListener(decListener());

    number = 50;
    label = new JLabel();
}

public class incListener implements ActionListener {
    public void actionPerformed (ActionEvent event) {
        number++;
        label.setText("" + number);
    }
}

public class decListener implements ActionListener {
    public void actionPerformed (ActionEvent event) {
        number--;
        label.setText("" + number);
    }
}

public static void main(String[] args) {
    Main dialog = new Main();
    dialog.pack();
    dialog.setVisible(true);
    System.exit(0);

}
}