java - java gui中文本框的正则表达式

Question

我正在尝试在文本框中执行用户输入，以检查他们是否在文本框中输入了用户名的任何数字或特殊字符。我在网上检查了一些资源也无法找出我的代码中的问题。它向我显示了四个错误消息
1) 错误:'else' 没有 'if'

 else if(tf3.getText().isEmpty())

2.) 错误:';'预计

if(!(Pattern.matches("^[a-zA-Z]$")),tf3.getText())

3.) 错误:此处不允许变量声明

if(!(Pattern.matches("^[a-zA-Z]$")),tf3.getText())

4.) 错误:';'预计

if(!(Pattern.matches("^[a-zA-Z]$")),tf3.getText())

这是我的整个程序的完整程序

 if(e.getSource()== btn2)
       {

        if(!(Pattern.matches("^[a-zA-Z]$")),tf3.getText())
         {
            JOptionPane.showMessageDialog(null,"Please enter a valid name");
         }
         else if(tf3.getText().isEmpty())
         {
            JOptionPane.showMessageDialog(null,"Check your name");
         }
         else if(tf2.getText().isEmpty())
         {
             JOptionPane.showMessageDialog(null,"Check your id");
         }
         else if(cmb1.getSelectedIndex()== 0)
         {
             JOptionPane.showMessageDialog(null,"Check your year");
         }
         else if(cmb2.getSelectedIndex()== 0)
         {
             JOptionPane.showMessageDialog(null,"Check your major");
         }
         else if(cmb3.getSelectedIndex() == 0)
         {
              JOptionPane.showMessageDialog(null,"Check your selection");
         }
         else
         {
         String name = tf3.getText();
         String id = tf2.getText();
         String job = String.valueOf(cmb1.getSelectedIndex());
         String country = String.valueOf(cmb2.getSelectedIndex());
         String software = String.valueOf(cmb3.getSelectedIndex());
         runCC(software,id,name,job,country);
         }
       }

Answer 1

括号:

if(!(Pattern.matches("^[a-zA-Z]$")),tf3.getText())

应该看起来像:

if(!Pattern.matches("^[a-zA-Z]$", tf3.getText()))

至少如果我明白你的意思的话。