Question

验证部分中的

问题，没有显示有关空白字段的消息。立即帮助

private void addbtnActionPerformed（java.awt.event.ActionEvent evt）{

    try{

    Class.forName("com.mysql.cj.jdbc.Driver");
    Connection con =DriverManager.getConnection("jdbc:mysql://localhost:3306/dbfinance","root","1234");
    String sql="insert into util(type_,due_date,month_,amount,units,status_) values(?,?,?,?,?,?)";
    PreparedStatement pstm =con.prepareStatement(sql);

    pstm.setString(1,electype.getSelectedItem().toString());
    pstm.setString(2,date.getText().toString());
    pstm.setString(3,jComboBox1.getSelectedItem().toString());
    pstm.setDouble(4,Double.parseDouble(amount.getText()));
    pstm.setString(5,unit.getText());
    pstm.setString(6,status.getText());



   pstm.executeUpdate();
   JOptionPane.showMessageDialog(null, "success");
   con.close();

        }catch(Exception e){

            JOptionPane.showMessageDialog(null,e);

        }
     if(amount.getText().isEmpty()||unit.getText().isEmpty()||status.getText().isEmpty()){

            JOptionPane.showMessageDialog(null,"please enter data");

           // errorname2.setText("fill this field");
    }        
}

Answer 1

在应用try-catch语句之前，请尝试验证您的金额字段是否为空：

if(amount.getText().isEmpty()||unit.getText().isEmpty()||status.getText().isEmpty()){
        JOptionPane.showMessageDialog(null,"please enter data");
        // errorname2.setText("fill this field");
    }else{
        try{
            Class.forName("com.mysql.cj.jdbc.Driver");
            Connection con =DriverManager.getConnection("jdbc:mysql://localhost:3306/dbfinance","root","1234");
            String sql="insert into util(type_,due_date,month_,amount,units,status_) values(?,?,?,?,?,?)";
            PreparedStatement pstm =con.prepareStatement(sql);
            pstm.setString(1,electype.getSelectedItem().toString());
            pstm.setString(2,date.getText().toString());
            pstm.setString(3,jComboBox1.getSelectedItem().toString());
            pstm.setDouble(4,Double.parseDouble(amount.getText()));
            pstm.setString(5,unit.getText());
            pstm.setString(6,status.getText());
            pstm.executeUpdate();
            JOptionPane.showMessageDialog(null, "success");
            con.close();

        }catch(Exception e){
            JOptionPane.showMessageDialog(null,e);
        }
    }

Answer 2

在验证之前，您不应该将数据插入数据库中。如果数据不为空，则仅插入数据。至于检查数据是否为空，最好对文本进行修剪，以便给定空白表示某些值，从而将所有空白都修剪掉。

if(amount.getText().trim().isEmpty()||unit.getText().trim().isEmpty()||
            status.getText().trim().isEmpty()){
        JOptionPane.showMessageDialog(null,"please enter data");
        // errorname2.setText("fill this field");
    }

请确保将修剪后的数据插入数据库中。

“文本字段验证无法正常工作”

2 个答案: