java - 在netbeans中使用java swing的登录页面

Question

我正在使用 netbeans 中的 java swing 制作登录页面。当我尝试单击“登录”按钮时，输入凭据后，下一个页面不可见。我曾经NextPage().setVisible(true)这样做过。我应该使用其他东西吗？

Answer 1

你在登录页面上使用过 actionListener() 吗？单击登录按钮时使用它转到下一页并在下一页上将其设置为可见（true）。

Answer 2

你必须使用 new Nextpage().setVisible(True);

Answer 3

这就是我的登录页面从数据库中获取数据的方式

try{
    Class.forName("java.sql.Driver");
    Connection con=DriverManager.getConnection("jdbc:mysql://localhost/restman","root","1234");
    Statement stmt=con.createStatement();
    String pq="select * from employeelogin";
    ResultSet rs=stmt.executeQuery(pq);
    String user=a1.getText();
    String psw=a2.getText();
    while(rs.next()){
        String uname=rs.getString("username");
        String password=rs.getString("password");
        if ((user.equals(uname))&&(psw.equals(password))) {
            new customerservice().setVisible(true);
            this.setVisible(false);
        } else {
            p1.setVisible(true);
        }
    }
} catch(Exception x) {
   JOptionPane.showMessageDialog(null,x.getMessage());
}

Answer 4

这是我的一段代码。登录请参见最后：

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         

    Connection conn=null;
    try{
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException ex) {
               Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
        }
        conn =DriverManager.getConnection(DB_URL, USER, PASS);
        Statement stmt=conn.createStatement();

        String S1 = jTextField1.getText();
        String S2 = jPasswordField1.getText().toString();
        String S3=jComboBox2.getSelectedItem().toString();

        if(S1.isEmpty() || S1 == null){
            JOptionPane.showMessageDialog(null, "Please insert a valid user name", "Warning", JOptionPane.WARNING_MESSAGE);
            return;
        }
        // if password is blank, warning message shown
        if(S2.isEmpty() || S2 == null){
            JOptionPane.showMessageDialog(null, "Password field is empty", "Warning", JOptionPane.WARNING_MESSAGE);
            return;
        }

        int flag=0;
        String sql;
        sql="SELECT * from member where EMAIL='"+S1+"'";
        ResultSet rs=stmt.executeQuery(sql);
        //System.out.println(rs.next());
        String uname="",pw="",category="";
        while(rs.next()){                       
            uname=rs.getString("EMAIL");
            pw=rs.getString("PASSWORD");
            category=rs.getString("CATEGORY");

            if(uname.matches(S1) && pw.equals(S2)==true && category.matches(S3))
            {
                flag=1;

                if(jComboBox2.getSelectedItem()=="VISITOR")
                {
                    setVisible(false);
                    Newvisitor f1= new Newvisitor(S1);
                    f1.getContentPane().setBackground(Color.darkGray);
                    f1.setVisible(true);
                    // jButton6.setVisible(true);
                }
                else if(jComboBox2.getSelectedItem()=="ACCOUNTANT")
                {
                    setVisible(false);
                    inter4 f=new inter4();
                    f.getContentPane().setBackground(new java.awt.Color(153,153,255));
                    f.setVisible(true);
                }
                else if(jComboBox2.getSelectedItem()=="ADMINISTRATOR")
                {
                    setVisible(false);
                    Admin f2=new Admin();
                    f2.getContentPane().setBackground(Color.darkGray);
                    f2.setVisible(true);
                }
            }
        } 
        if(flag==0)
            JOptionPane.showMessageDialog(null,"login failed");      
        stmt.close();
        conn.close();
    }
    catch(SQLException ss){
        ss.printStackTrace(); 
    }   `
}