我的Java代码怎么添加事件：点击“加水”，“请加水”就变成“不需要加水”​

import javax.swing.JLabel;
import javax.swing.JPanel;

public class Left {

private JLabel textWater = new JLabel("请加水");
private JPanel panel1 = new JPanel();

public Left(){
    panel1.add(textWater);
}

public JPanel getPanel1() {
    return panel1;
}

public void setPanel1(JPanel panel1) {
    this.panel1 = panel1;
}

}
/***********************************************************************************/

import javax.swing.JButton;
import javax.swing.JPanel;

public class Right{

private JButton addwater = new JButton("加水");
private JPanel panel3 = new JPanel();

public Right(){
    panel3.add(addwater);
}

public JPanel getPanel3() {
    return panel3;
}

public void setPanel3(JPanel panel3) {
    this.panel3 = panel3;
}

}
/***********************************************************************************/

import java.awt.FlowLayout;
import javax.swing.JFrame;

public class Test extends JFrame{

public Test(){
    super("咖啡机");
    this.setSize(200,200);
    this.setLayout(new FlowLayout());
    Left left = new Left();
    Right right = new Right();
    this.add(left.getPanel1());
    this.add(right.getPanel3());
    this.setLocationRelativeTo(null);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
}
public static void main(String[] args) {
    new Test();
}

}
点击“加水”，“请加水”就变成“不需要加水”

在Button的Clicked事件里写代码，根据按钮的当前文本来判断，如果是“加水”就变成“不需要加水”

楼上正解，替换button的文本