servlet服务器端验证(9)

import java.io.IOException; 
import java.util.ArrayList; 
 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
public class login extends HttpServlet { 
 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException { 
        response.setContentType("text/html;charset=GBK"); 
        request.setCharacterEncoding("GBK"); 
         
        //String name = request.getParameter("username");  
        String newname = new String(request.getParameter("username").getBytes("ISO-8859-1"),"GBK"); 
        String password1 = request.getParameter("password1"); 
        String password2 = request.getParameter("password2"); 
         
        ArrayList l = new ArrayList(); 
        if (newname.equals("") || newname.equals(null)) { 
            l.add("用户不为空"); 
 
        } 
        if (password1== null || password1.length() < 4 || password1.length() > 10) { 
            l.add("密码的长度4-10位"); 
 
        } 
        if (password2 == null || password2.length() < 4 || password2.length() > 10) { 
            l.add("确认密码的长度4-10位"); 
 
        } 
        if (password1 != null && password2 != null 
                && !password1.equals(password2)) { 
            l.add("密码和确认密码应该一致"); 
 
        } 
        if (l.isEmpty()) { 
            request.setAttribute("name", newname);