但是在另一个类的set方法中,当我得到的值是存在的,所以我有3个类--第一类是getter setter类,第二个类是填充集合的类,最后一个类是获取方法getter的类,但是它是空值.
public class loginAdminn {
String Username, Password;
public String getUsername() {
return Username;
}
public void setUsername(String Username) {
this.Username = Username;
}
public String getPassword() {
return Password;
}
public void setPassword(String Password) {
this.Password = Password;
}
}
// method to fill the set on another class
public void in(){
loginAdminn p = new loginAdminn();
String user = Username.getText();
String pass = Password.getPassword().toString();
p.setUsername(user);
p.setPassword(pass);
// new NewMain().run();
tes.jalankan();
}
// class method getter (null)
public void jalankan() {
loginAdminn br = new loginAdminn();
String kueri = "Select Username, password from Admin";
int x = 0;
try {
ps = conn.prepareStatement(kueri);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
if (br.getUsername().equalsIgnoreCase(rs.getString("Username"))) {
if (br.getPassword().equalsIgnoreCase(rs.getString("Password"))) {
JOptionPane.showMessageDialog(null, "Masuk Berhasil");
x = 1;
break;
}
}
}
if (x == 1) {
HomeAdmin b = new HomeAdmin();
b.setVisible(true);
} else {
JOptionPane.showMessageDialog(null, "Masuk Gagal");
DaftarAplikasi da = new DaftarAplikasi();
da.setVisible(true);
}
ps.close();
} catch (SQLException ex) {
JOptionPane.showMessageDialog(null, ex.getMessage());
}
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
//the getUsername and getPassword goes null发布于 2019-08-17 15:19:30
A类
String x;
setter getter x
A c = new A();
c.get... // object Class A type XB类
A c = new A();
c.get... // object Class B type X
c.get from Class A != c.get from Class B基本上,通过使用new,您可以创建两个相互独立的对象!
发布于 2017-05-07 04:23:34
您的getUserName()将为空,因为用于比较的对象没有分配给它的userName值。
public void jalankan() {
//creating an object here , br has no username assigned
loginAdminn br = new loginAdminn();
String kueri = "Select Username, password from Admin";
int x = 0;
try {
ps = conn.prepareStatement(kueri);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
if (br.getUsername().equalsIgnoreCase(rs.getString("Username"))) {
if (br.getPassword().equalsIgnoreCase(rs.getString("Password"))) {
JOptionPane.showMessageDialog(null, "Masuk Berhasil");
x = 1;
break;
}
}
}在读取br.getUserName()时,应该给出null。
https://stackoverflow.com/questions/43827700
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