do..while的SB问题，分多人傻，请速来！

[Z.Chen]

输入有效性验证。
在swing里面输入学生姓名，如果没有输入任何东西直接点确认，需要跳出提示，然后重复跳出输入框，要求再次输入。

JOptionPane jop = new JOptionPane();

student.name = jop.showInputDialog("Enter Student Name");
String receiveName = student.name;
do{
        student.name = jop.showInputDialog("Enter Student Name");
        jop.showMessageDialog(null, "Please enter valid information!!!!", "Input",JOptionPane.WARNING_MESSAGE);

}while(receiveName == null || receiveName.equals(""));

我写的do while逻辑有点不对，缺点东西，导致运行时不断陷入错误提示，哪怕输入了姓名还是会有错误提示。
我觉得应该在第8行再加个while来跳出循环，但是又不确定怎么写。请高手帮忙。
谢谢。

[Sh@dow]

改成用if语句判断就可以了

[Z.Chen]

if语句只能重复一次，第二次输入为空就不行了。。。

[再启动]

JOptionPane jop = new JOptionPane(); String receiveName = null; do{ student.name = jop.showInputDialog("Enter Student Name"); receiveName = student.name; if (receiveName == null || receiveName.equals("")) { jop.showMessageDialog(null, "Please enter valid information!!!!", "Input",JOptionPane.WARNING_MESSAGE); } }while(receiveName == null || receiveName.equals(""));

[Z.Chen]

引用 3 楼 再启动 的回复:

JOptionPane jop = new JOptionPane(); String receiveName = null; do{ student.name = jop.showInputDialog("Enter Student Name"); receiveName = student.name; if (receiveName == null || receiveName.equals("")) { jop.showMessageDialog(null, "Please enter valid information!!!!", "Input",JOptionPane.WARNING_MESSAGE); } }while(receiveName == null || receiveName.equals(""));

跪谢版主大人。。。