回复 2楼 岁月如刀
											改成一个对话框?怎么改啊?什么对话框啊?我是菜鸟啊
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSession;
import javax.swing.JOptionPane;
/**
 * @author Administrator
 *
 */
public class UserBean {
    private java.lang.String userName;
    private java.lang.String password;
    public UserBean() {
    }
public java.lang.String getUserName() {
        return userName;
    }
 public void setUserName(java.lang.String userName) {
        this.userName = userName;
    }
 public java.lang.String getPassword() {
        return password;
    }
public void setPassword(java.lang.String password) {
        this.password = password;
    }
 public String loginUser() { 
    if("myeclipse".equals(getUserName()) && "myeclipse".equals(getPassword())) 
            {return "success"; }
        else if("".equals(getUserName())||getUserName() == null)
            {
            JOptionPane.showMessageDialog( null,"用户名不能为空");     这里怎么定父窗口啊???
          return "re";}
        else if(!"".equals(getUserName()) && "".equals(getPassword()))
                {
JOptionPane.showMessageDialog(null,"请输入密码!!");
            return"re";}
           return "failure";} 
    public String exitUser(){
        int returnValue;
        returnValue = 
JOptionPane.showConfirmDialog(null, "确实要退出吗?", "退出程序", JOptionPane.YES_NO_OPTION);
        if (returnValue == JOptionPane.YES_OPTION)
        {FacesContext fc = FacesContext.getCurrentInstance();
        HttpSession session = (HttpSession) fc.getExternalContext().getSession(false);
        session.invalidate();
        return "exit";}
        else return "";
    }
    public String reLogin(){
        return "re";
    }
    private String message;
    public String getMessage() {
    return message;
    }
    public void setMessage(String message) {
    this.message = message;
    }
    }