jsp的防sql注入通用程序

public static boolean sql_inj(String str) 
 {
 String inj_str = "'|and|exec|insert|select|delete|update|count|*|%|chr|mid|master|truncate|char|declare|;|or|-|+|,";
 String inj_stra[] = split(inj_str,"|");
 for (int i=0 ; i < inj_stra.length ; i++ )
 {
 if (str.indexOf(inj_stra[i])>=0)
 {
 return true;
 }
 }
 return false;
 }jsp中调用该函数检查是否包函非法字符
 <%
 if(request.getParameter("userID") != null)
 userID = request.getParameter("userID").trim();if (StringUtil.sql_inj(userID) || StringUtil.sql_inj(pwd)){
 %>
 <Script Language=javascript>alert('参数中包含非法字符！');history.back(-1);</Script>" ;
 <%
 }else{
 ……
 }%>