如何检查JPassword字段是否为空 [英] How to check if JPassword field is null
本文介绍了如何检查JPassword字段是否为空的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想检查Swing中的用户名和密码。
I want to check the username and password in Swing.
该检查适用于用户名,但不适用于JPaswordfield。我发布相关代码:
The check works for username, but it doesn't work for JPaswordfield. I am posting the related code:
//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
推荐答案
使用 JPasswordField#getPassword()
返回 char []
的文本,然后只需获取数组的长度并检查它是否等于0:
Very simple get the text using JPasswordField#getPassword()
which returns a char[]
of the text, then simply get the length of the array and check if it is equal to 0:
JPasswordField jpf...
if(jpf.getPassword().length == 0) {
// it is empty
}else {
// it is not empty
}
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