我想在 Swing 中检查用户名和密码。
该检查适用于用户名,但不适用于 JPaswordfield。我贴出相关代码:
//Here I get the password
Char[] pwd = jt1.getPassword();
String s = new String(pwd); //converting char to string
String p = s;
//In the JButton checking username and password(Username check works fine but not passwordfield)
jb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
if ((jt.getText().length()) == 0)
{
JFrame jf1 = new JFrame("UserName");
jf1.setSize(401, 401);
//jf1.setVisible(true);
jf1.setDefaultCloseOperation(jf1.EXIT_ON_CLOSE);
JOptionPane.showMessageDialog(jf1, "User Name is empty");
}
else if((p.length()) == 0)
{
JFrame jf1 = new JFrame("Password");
jf1.setSize(401, 401);
//jf1.setVisible(true);
jf1.setDefaultCloseOperation(jf1.EXIT_ON_CLOSE);
JOptionPane.showMessageDialog(jf1, "Password is empty");
}
else if ((p.length() == 0) && (jt.getText().length()) == 0)
{
JFrame jf1 = new JFrame("UserName and Password");
jf1.setSize(401, 401);
//jf1.setVisible(true);
jf1.setDefaultCloseOperation(jf1.EXIT_ON_CLOSE);
JOptionPane.showMessageDialog(jf1, "Username and Password is
empty");
}
else
{ //go to another method}
Can someone help
最佳答案
使用 JPasswordField#getPassword()
获取文本非常简单它返回文本的 char[]
,然后简单地获取数组的长度并检查它是否等于 0:
JPasswordField jpf...
if(jpf.getPassword().length == 0) {
// it is empty
}else {
// it is not empty
}
关于java - 如何检查 JPassword 字段是否为空,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13460582/