UC知道equals的问题
来源：百度知道 编辑：UC知道 时间：2024/05/17 04:55:39
<%@ include file="conn.jsp"%>
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%
String user_name=request.getParameter("user");
String password=request.getParameter("psd");
if((password==null)||(user_name==null)||(password=="")||(user_name=="")){
out.print("<script language='javascript'>");
out.print("alert('用户名和密码不能为空!或者存在不合法字符！');");
out.print("history.go(-1);");
out.print("</script>");
}else{
String sql="select * from users where name ='"+user_name+"' and password ='"+ password+"'";
ResultSet rs_user=stmt.executeQuery(sql);
if(!rs_user.next()){
out.print("<script language='javascript'>");
o
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%
String user_name=request.getParameter("user");
String password=request.getParameter("psd");
if((password==null)||(user_name==null)||(password=="")||(user_name=="")){
out.print("<script language='javascript'>");
out.print("alert('用户名和密码不能为空!或者存在不合法字符！');");
out.print("history.go(-1);");
out.print("</script>");
}else{
String sql="select * from users where name ='"+user_name+"' and password ='"+ password+"'";
ResultSet rs_user=stmt.executeQuery(sql);
if(!rs_user.next()){
out.print("<script language='javascript'>");
o
nn.close(); ------此处nn已经关闭
rs_user.close();
if("admin".equals(nn.getString("role")){ -----此处又用nn??? 检查下
response.sendRedirect("super.jsp");
}else{
response.sendRedirect("cart2.jsp");}
}
}
String user_name=request.getParameter("user");
String password=request.getParameter("psd");
""不能用 == 做判断
if((password==null)||(user_name==null)||(password=="")||(user_name==""))
应该修改为password.equals("")...
user_name.trm()
password.trm()
nn.getString("role").trm()
加个trm（）-去掉字符串前面和后面的空格（不包括字符串里面的空格），看看
把nn.getstring("role")打印 出来看是什么东西不就知道了吗.