新人卑微求学。。这要咋办啊

求大佬帮忙改一下

package gui;
import java.awt.Graphics;
import java.awt.HeadlessException;
import java.awt.Image;
import java.sql.SQLException;
import java.util.ArrayList;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;

import dao.*;
public class Addition extends javax.swing.JFrame {
public Addition() {
initComponents();
}
@SuppressWarnings("unchecked")
/** */

private void initComponents() {
setLocationRelativeTo(null);
jPanel1 = new javax.swing.JPanel() {
@Override
public void paintComponent(Graphics g) {
ImageIcon icon=new ImageIcon("image/背景.jpg");
Image img = icon.getImage();
g.drawImage(img, 0, 0,this.getWidth(), this.getHeight(), this);
}
};
jLabel4 = new javax.swing.JLabel();
stunum = new javax.swing.JTextField();
jLabel5 = new javax.swing.JLabel();
name = new javax.swing.JTextField();
jLabel6 = new javax.swing.JLabel();
classes = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
java = new javax.swing.JTextField();
jLabel7 = new javax.swing.JLabel();
gender = new javax.swing.JTextField();
jLabel8 = new javax.swing.JLabel();
math = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
add = new javax.swing.JButton();
back = new javax.swing.JButton();
jLabel9 = new javax.swing.JLabel();
english = new javax.swing.JTextField();

    setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

    jLabel4.setText("Stuno：");

    stunum.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    stunum.setToolTipText("");
    stunum.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            stunumActionPerformed(evt);
        }
    });

    jLabel5.setText("Name：");

    name.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    name.setToolTipText("");
    name.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            nameActionPerformed(evt);
        }
    });

    jLabel6.setText("Class：");

    classes.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    classes.setToolTipText("");
    classes.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            classesActionPerformed(evt);
        }
    });

    jLabel1.setText("Java：");

    java.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    java.setToolTipText("");
    java.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            javaActionPerformed(evt);
        }
    });

    jLabel7.setText("Gender：");

    gender.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    gender.setToolTipText("");
    gender.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            genderActionPerformed(evt);
        }
    });

    jLabel8.setText("Math：");

    math.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    math.setToolTipText("");
    math.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            mathActionPerformed(evt);
        }
    });

    jLabel2.setFont(new java.awt.Font("宋体", 0, 24)); 
    jLabel2.setText("增加学生信息：");

    add.setFont(new java.awt.Font("宋体", 0, 18)); 
    add.setText("增加");
    add.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            addActionPerformed(evt);
        }
    });

    back.setFont(new java.awt.Font("宋体", 0, 18)); 
    back.setText("返回");
    back.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            backActionPerformed(evt);
        }
    });

    jLabel9.setText("English：");

    english.setHorizontalAlignment(javax.swing.JTextField.TRAILING);
    english.setToolTipText("");
    english.addActionListener(new java.awt.event.ActionListener() {
        @Override
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            englishActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(39, 39, 39)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(jLabel5)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel4)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                            .addComponent(stunum, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(31, 31, 31)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                        .addComponent(jLabel6)
                        .addComponent(jLabel7))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(classes, javax.swing.GroupLayout.DEFAULT_SIZE, 100, Short.MAX_VALUE)
                        .addComponent(name)
                        .addComponent(gender)))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(39, 39, 39)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(jLabel1)
                        .addComponent(jLabel8))
                    .addGap(22, 22, 22)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(math, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(java, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(31, 31, 31)
                    .addComponent(jLabel9)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addComponent(english, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 96, Short.MAX_VALUE)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                .addComponent(add, javax.swing.GroupLayout.DEFAULT_SIZE, 98, Short.MAX_VALUE)
                .addComponent(back, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGap(80, 80, 80))
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel2)
            .addGap(0, 0, Short.MAX_VALUE))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel2)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                .addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(6, 6, 6)
                    .addComponent(stunum)))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(6, 6, 6)
                            .addComponent(name)))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(jLabel6, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(classes, javax.swing.GroupLayout.DEFAULT_SIZE, 36, Short.MAX_VALUE)))
                .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                    .addComponent(add, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(16, 16, 16)))
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(jLabel7, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(6, 6, 6)
                            .addComponent(gender, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(6, 6, 6)
                            .addComponent(java))))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(16, 16, 16)
                    .addComponent(back, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jLabel8, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(math, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jLabel9, javax.swing.GroupLayout.PREFERRED_SIZE, 36, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(english, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addContainerGap())
    );

    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)
        .addGroup(layout.createSequentialGroup()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(0, 0, Short.MAX_VALUE))
    );

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

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

}                                      

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

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

}                                       

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

}                                    

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

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

private void addActionPerformed(java.awt.event.ActionEvent evt){ 
    boolean flag1=false;
    String str="[0-9]*";
    String male="m";
    String female="f";
    int count=5;
    double max=100;

    try {
        flag1 = new StudentDaoJDB().findStudentByStunum1(stunum.getText());
    } catch (SQLException e) {
        // TODO 自动生成的 catch 块
        e.printStackTrace();
    }
    if(stunum.getText().length()==0||classes.getText().length()==0||gender.getText().length()==0||name.getText().length()==0||java.getText().length()==0||math.getText().length()==0||english.getText().length()==0)
    {
        javax.swing.JOptionPane.showMessageDialog(null, "不能有信息为空，请重新填.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }
    else if(stunum.getText().length()<count||!stunum.getText().matches(str))
    {
        javax.swing.JOptionPane.showMessageDialog(null, "学号信息有误,必须为5位数!请重新填.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }
    else if(!classes.getText().matches(str))
    {
        javax.swing.JOptionPane.showMessageDialog(null, "班级信息有误!请重新填.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }
    else if(!(female.equals(gender.getText())||male.equals(gender.getText())))
    {
        javax.swing.JOptionPane.showMessageDialog(null, "性别信息有误!请重新填.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }
    else if(Double.parseDouble(java.getText())<0||Double.parseDouble(java.getText())>max||Double.parseDouble(math.getText())<0||Double.parseDouble(math.getText())>max||Double.parseDouble(english.getText())<0||Double.parseDouble(english.getText())>max)
    {
        javax.swing.JOptionPane.showMessageDialog(null, "成绩信息有误!请重新填.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }

    else if(flag1)
    {
        javax.swing.JOptionPane.showMessageDialog(null, "该学号已存在!请重新输入.", "提示",javax.swing.JOptionPane.PLAIN_MESSAGE);  
        this.setVisible(true);
    }
    else {
    stu=new Student();
    stu.setStunum(stunum.getText());
    stu.setClasses(Integer.parseInt(classes.getText()));
    stu.setGender(gender.getText());
    stu.setName(name.getText());
    ArrayList<Course> scoreList=new ArrayList<Course>();
    Course javaScore=new Course("java",Double.valueOf(java.getText()));
    Course mathScore=new Course("math",Double.valueOf(math.getText()));
    Course englishScore=new Course("english",Double.valueOf(english.getText()));
    scoreList.add(javaScore);
    scoreList.add(mathScore);
    scoreList.add(englishScore);
    stu.setScoreList(scoreList);

    int res=JOptionPane.showConfirmDialog(null,"是否确认添加?","是否继续", JOptionPane.YES_NO_OPTION);
    if(res==JOptionPane.YES_OPTION){
        boolean flag=new StudentDaoJDB().writeStudent(stu);
        if(flag)
        { JOptionPane.showMessageDialog(null, "添加成功！", "success",JOptionPane.OK_OPTION);}
        else
        {JOptionPane.showMessageDialog(null, "添加失败！", "failed",JOptionPane.OK_OPTION);    }
    }
    else{
         JOptionPane.showMessageDialog(null, "取消操作", "failed",JOptionPane.OK_OPTION);
    }
    }
}                                   

private void backActionPerformed(java.awt.event.ActionEvent evt) {                                     
    this.setVisible(false);
    new Teacherfunction().setVisible(true);  
}                                    

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

/**
 * @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(Addition.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(Addition.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(Addition.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(Addition.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

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

/** Variables declaration - do not modify  */                   
private javax.swing.JButton add;
private javax.swing.JButton back;
private javax.swing.JTextField classes;
private javax.swing.JTextField english;
private javax.swing.JTextField gender;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JPanel jPanel1;
private javax.swing.JTextField java;
private javax.swing.JTextField math;
private javax.swing.JTextField name;
private javax.swing.JTextField stunum;
private Student stu;
// End of variables declaration                   

}

检查一下包有没有import进来吧。
友情提醒一句：学Java直接跳过图形界面编程（Swing+AWT）......

给你引用这个报错的所有方法改成 public static 修饰试一下？