Forms 制作登录表单。如果block运行良好,但else block未执行
private void btn_registerActionPerformed(java.awt.event.ActionEvent evt){Forms 制作登录表单。如果block运行良好,但else block未执行,forms,login,Forms,Login,private void btn_registerActionPerformed(java.awt.event.ActionEvent evt){ String username=reg_username.getText(); String password=reg_password.getText(); int age=Integer.parseInt(reg_age.getText()); String gender=null; if(reg_rdom
String username=reg_username.getText();
String password=reg_password.getText();
int age=Integer.parseInt(reg_age.getText());
String gender=null;
if(reg_rdomale.isSelected()){
gender="Male";
}else if(reg_rdofemale.isSelected()){
gender="Female";
}
String country=reg_country.getSelectedItem().toString();
try {
Statement st=conn.createStatement();
String Querytwo=("select * from registrationform where UserName='"+reg_username.getText()+"'");
ResultSet rs=st.executeQuery(Querytwo);
while(rs.next())
if(rs.getString(1).equals(reg_username.getText())){
JOptionPane.showMessageDialog(this, "UserName Already Exists.");
}else{
String Query="insert into registrationform values('"+username+"','"+password+"','"+age+"','"+gender+"','"+country+"')";
st.execute(Query);
JOptionPane.showMessageDialog(this, "SignUp Complete\nYou are now Registered.");
}
} catch (SQLException ex) {
Logger.getLogger(insert.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(this, ex.getMessage());
}
}
//如果我只使用插入块,它绝对有效。但是当我添加if-else来比较用户名是否已经存在时。当条件变为false时,它会执行if-block而不是else-block你的问题是什么?对不起,我是新来的,花了一段时间来理解发布过程。现在看我的问题:)一个叫christian的家伙修改了编辑此正文中的128个字符。这是什么我不明白。请提供我了解此网站的任何链接。
String username=reg_username.getText();
String password=reg_password.getText();
int age=Integer.parseInt(reg_age.getText());
String gender=null;
if(reg_rdomale.isSelected()){
gender="Male";
}else if(reg_rdofemale.isSelected()){
gender="Female";
}
String country=reg_country.getSelectedItem().toString();
try {
Statement st=conn.createStatement();
String Querytwo=("select * from registrationform where UserName='"+reg_username.getText()+"'");
ResultSet rs=st.executeQuery(Querytwo);
while(rs.next())
if(rs.getString(1).equals(reg_username.getText())){
JOptionPane.showMessageDialog(this, "UserName Already Exists.");
}else{
String Query="insert into registrationform values('"+username+"','"+password+"','"+age+"','"+gender+"','"+country+"')";
st.execute(Query);
JOptionPane.showMessageDialog(this, "SignUp Complete\nYou are now Registered.");
}
} catch (SQLException ex) {
Logger.getLogger(insert.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(this, ex.getMessage());
}
}