Java 无法将变量传递给其他类

我正在尝试创建一个计时器，该计时器将显示在JLabel内部，我知道代码本身的工作原理与我使用System.out.println尝试的一样，但我不知道如何使另一个类看到JLabel

我是一个完全的初学者，从昨天早上开始就一直在努力想办法。我试着用谷歌搜索，看视频教程，阅读教程，找到类似的问题，使用getter和setter，使用不同的变量。没有任何帮助。我确实意识到这是一个非常容易的问题，但我无法解决它，我真的非常感谢任何形式的帮助

包含计时器代码的类：

    package Timernew;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class newTimer {    

    Timer timer = null;
    int counter = 5;
    int delay = 1500;

//method that will be called when the timer needs to start

    public void startTimer() {


        ActionListener action = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event) {

                if (counter == 0) {
                    timer.stop();

                    lblTimerE.setText("Time up");
                } else {
                    lblTimerE.setText("Wait for " + counter + " sec");
                    counter--;
                }
            }
        };  //end of action performed statement

        timer = new Timer(delay, action);
        timer.setInitialDelay(0);
        timer.start(); //this will start the timer


    } //end of method

}

    package Timernew;

import javax.swing.JLabel;


public class Easy extends javax.swing.JFrame {

         newTimer time = new newTimer();




    /**
     * Creates new form Easy
     */
    public Easy() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        lblTimerE = new javax.swing.JLabel();
        btnStart = new javax.swing.JButton();
        lblWordE = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBackground(new java.awt.Color(204, 255, 0));

        lblTimerE.setText("                       ");

        btnStart.setText("Start");
        btnStart.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btnStartActionPerformed(evt);
            }
        });

        lblWordE.setText("                                                       ");

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(134, 134, 134)
                .addComponent(lblTimerE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 243, Short.MAX_VALUE)
                .addComponent(btnStart)
                .addGap(58, 58, 58))
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(196, 196, 196)
                .addComponent(lblWordE, javax.swing.GroupLayout.PREFERRED_SIZE, 186, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(45, 45, 45)
                        .addComponent(lblTimerE))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(60, 60, 60)
                        .addComponent(btnStart)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 133, Short.MAX_VALUE)
                .addComponent(lblWordE, javax.swing.GroupLayout.PREFERRED_SIZE, 91, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(54, 54, 54))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>                        

    private void btnStartActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:

        time.startTimer();


    }                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Easy().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    public javax.swing.JButton btnStart;
    public javax.swing.JPanel jPanel1;
    public javax.swing.JLabel lblTimerE;
    public javax.swing.JLabel lblWordE;
    // End of variables declaration                   
}

包含JLabel和触发器按钮的类：

    package Timernew;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class newTimer {    

    Timer timer = null;
    int counter = 5;
    int delay = 1500;

//method that will be called when the timer needs to start

    public void startTimer() {


        ActionListener action = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event) {

                if (counter == 0) {
                    timer.stop();

                    lblTimerE.setText("Time up");
                } else {
                    lblTimerE.setText("Wait for " + counter + " sec");
                    counter--;
                }
            }
        };  //end of action performed statement

        timer = new Timer(delay, action);
        timer.setInitialDelay(0);
        timer.start(); //this will start the timer


    } //end of method

}

    package Timernew;

import javax.swing.JLabel;


public class Easy extends javax.swing.JFrame {

         newTimer time = new newTimer();




    /**
     * Creates new form Easy
     */
    public Easy() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        lblTimerE = new javax.swing.JLabel();
        btnStart = new javax.swing.JButton();
        lblWordE = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBackground(new java.awt.Color(204, 255, 0));

        lblTimerE.setText("                       ");

        btnStart.setText("Start");
        btnStart.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btnStartActionPerformed(evt);
            }
        });

        lblWordE.setText("                                                       ");

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(134, 134, 134)
                .addComponent(lblTimerE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 243, Short.MAX_VALUE)
                .addComponent(btnStart)
                .addGap(58, 58, 58))
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(196, 196, 196)
                .addComponent(lblWordE, javax.swing.GroupLayout.PREFERRED_SIZE, 186, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(45, 45, 45)
                        .addComponent(lblTimerE))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(60, 60, 60)
                        .addComponent(btnStart)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 133, Short.MAX_VALUE)
                .addComponent(lblWordE, javax.swing.GroupLayout.PREFERRED_SIZE, 91, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(54, 54, 54))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>                        

    private void btnStartActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:

        time.startTimer();


    }                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Easy().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    public javax.swing.JButton btnStart;
    public javax.swing.JPanel jPanel1;
    public javax.swing.JLabel lblTimerE;
    public javax.swing.JLabel lblWordE;
    // End of variables declaration                   
}

---

我复制了您的代码，并对其进行了一些调整：因为您似乎需要在

NewTimer

类中使用JLabel，所以我将其作为构造函数参数传递。我没有触及代码的其余部分，因为这不是问题的一部分

    public class Easy extends javax.swing.JFrame {

        /**
         * @param args
         *           the command line arguments
         */
        public static void main(final String args[]) {
            /* Set the Nimbus look and feel */
            // <editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
            /*
             * If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. For details see
             * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
             */
            try {
                for (final javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                    if ("Nimbus".equals(info.getName())) {
                        javax.swing.UIManager.setLookAndFeel(info.getClassName());
                        break;
                    }
                }
            } catch (final ClassNotFoundException ex) {
                java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (final InstantiationException ex) {
                java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (final IllegalAccessException ex) {
                java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (final javax.swing.UnsupportedLookAndFeelException ex) {
                java.util.logging.Logger.getLogger(Easy.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            }
            // </editor-fold>

            /* Create and display the form */
            java.awt.EventQueue.invokeLater(() -> new Easy().setVisible(true));
        }

        NewTimer time;

        // Variables declaration - do not modify
        public javax.swing.JButton btnStart;

        public javax.swing.JPanel jPanel1;

        public javax.swing.JLabel lblTimerE;

        public javax.swing.JLabel lblWordE;

        // End of variables declaration
        /**
         * Creates new form Easy
         */
        public Easy() {
            initComponents();
        }

        private void btnStartActionPerformed(final java.awt.event.ActionEvent evt) {
            // TODO add your handling code here:

            time.startTimer();

        }

        /**
         * This method is called from within the constructor to initialize the form. WARNING: Do NOT modify this code. The content of this method is always regenerated by the Form
         * Editor.
         */
        @SuppressWarnings("unchecked")
        // <editor-fold defaultstate="collapsed" desc="Generated Code">
        private void initComponents() {

            jPanel1 = new javax.swing.JPanel();
            lblTimerE = new javax.swing.JLabel();
            btnStart = new javax.swing.JButton();
            lblWordE = new javax.swing.JLabel();

            time = new NewTimer(lblTimerE);

            setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

            // Rest of your code...
        }// </editor-fold>
    }

    public class NewTimer {
        JLabel lblTimerE;

        Timer timer = null;
        int counter = 5;
        int delay = 1500;

        public NewTimer(final JLabel lbl) {
            lblTimerE = lbl;
        }

        // method that will be called when the timer needs to start

        public void startTimer() {

            final ActionListener action = new ActionListener() {
                @Override
                public void actionPerformed(final ActionEvent event) {

                    if (counter == 0) {
                        timer.stop();

                        lblTimerE.setText("Time up");
                    } else {
                        lblTimerE.setText("Wait for " + counter + " sec");
                        counter--;
                    }
                }
            }; // end of action performed statement

            timer = new Timer(delay, action);
            timer.setInitialDelay(0);
            timer.start(); // this will start the timer

        } // end of method

    }

public类Easy扩展javax.swing.JFrame{
/**
*@param args
*命令行参数
*/
公共静态void main（最终字符串参数[]）{
/*设置Nimbus的外观和感觉*/
// 
/*
*如果Nimbus（在JavaSE6中引入）不可用，请使用默认的外观。有关详细信息，请参阅
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
试一试{
对于（最终javax.swing.UIManager.LookAndFeelInfo信息：javax.swing.UIManager.getInstalledLookAndFeels（））{
if（“Nimbus”.equals（info.getName（）））{
setLookAndFeel（info.getClassName（））；
打破
}
}
}捕获（最终类NotFoundException ex）{
getLogger（Easy.class.getName（））.log（java.util.logging.Level.SEVERE，null，ex）；
}捕获（最终实例化异常异常）{
getLogger（Easy.class.getName（））.log（java.util.logging.Level.SEVERE，null，ex）；
}捕获（最终非法访问例外）{
getLogger（Easy.class.getName（））.log（java.util.logging.Level.SEVERE，null，ex）；
}catch（final javax.swing.UnsupportedLookAndFeelException ex）{
getLogger（Easy.class.getName（））.log（java.util.logging.Level.SEVERE，null，ex）；
}
// 
/*创建并显示表单*/
invokeLater（（）->new Easy（）.setVisible（true））；
}
新时间；
//变量声明-不修改
public javax.swing.JButton btnStart；
public javax.swing.JPanel jPanel1；
public javax.swing.JLabel lblTimerE；
public javax.swing.JLabel lblWordE；
//变量结束声明
/**
*轻松创建新表单
*/
公共轻松（）{
初始化组件（）；
}
私有void btnStartActionPerformed（最终java.awt.event.ActionEvent evt）{
//TODO在此处添加您的处理代码：
time.startTimer（）；
}
/**
*从构造函数中调用此方法来初始化表单。警告：不要修改此代码。此方法的内容始终由表单重新生成
*编辑。
*/
@抑制警告（“未选中”）
// 
私有组件（）{
jPanel1=newjavax.swing.JPanel（）；
lblTimerE=newjavax.swing.JLabel（）；
btnStart=newjavax.swing.JButton（）；
lblWordE=newjavax.swing.JLabel（）；
时间=新的新时间（lbltimer）；
setDefaultCloseOperation（javax.swing.WindowConstants.EXIT_ON_CLOSE）；
//剩下的代码。。。
}// 
}
公共类新定时器{
JLabel-lblTimerE；
计时器=空；
int计数器=5；
int延迟=1500；
公共新计时器（最终JLabel lbl）{
lblTimerE=lbl；
}
//方法，该方法将在计时器需要启动时调用
公共无效startTimer（）{
最终ActionListener操作=新建ActionListener（）{
@凌驾
已执行的公共无效操作（最终操作事件）{
如果（计数器==0）{
timer.stop（）；
lblTimerE.setText（“时间到了”）；
}否则{
lblTimerE.setText（“等待”+计数器+“秒”）；
计数器--；
}
}
}；//执行的操作结束语句
定时器=新定时器（延迟、动作）；
timer.setInitialDelay（0）；
timer.start（）；//这将启动计时器
}//方法结束
}

请发布一个

lbltimer

变量，该变量在

newTimer

类中不存在（该类应称为

newTimer

，顺便说一句）-->您需要将其作为参数传递，或通过getter访问它感谢您的帮助，因为我使用的是netbeans，我无法编辑代码的某些部分，主要是“时间=新的新时间（lbltimer）；“。我将尝试更多，然后以另一种方式从头开始。为什么您不能编辑部分代码？它无法编译？（可能是正常的…）