用正則表達式判斷一個簡單的用戶登陸的例子

　　bdjsp

<%@ page contentType="text/html;charset=gb"%>
<% //接受表單提交的字符串
/*
數據只能為azAZ的字符的正則表達式的例子
正則表達式在做程序登陸的過程非常重要不然用´ or ´ 等語句就可以很容易繞過您的程度判斷
作者高頌 QQ: 一個簡單的例子但是很有用希望起到拋磚引玉的作用
*/
String temp ="我是非法的字符";
String name = requestgetParameter("name"); //應收金額
String pass = requestgetParameter("pass");
if (name==null){
name=temp;
}
if (pass==null){
pass=temp;
}
%>

<%!private boolean regex(String str){
javautilregexPattern p=null; //正則表達式
javautilregexMatcher m=null; //操作的字符串
boolean value=true;
try{
p = javautilregexPatterncompile("[^AZaz]");
m = pmatcher(str);
if(mfind()) {

value=false;
}
}catch(Exception e){}
return value;
}
%>

<html>
<title>信息輸入表單</title>
<body>
<form action = "bdjsp" method = "get" >
<div align="center"><font color="#FF">數據只能為azAZ的字符的正則表達式的例子</font>
<table border = "">
<tr>
<td bgcolor = "yellow">用戶</td>
<td><input name = "name" type = "text" id="name"></td>
</tr>
<tr>
<td width="" bgcolor = "yellow">密碼</td>
<td width=""> <input name = "pass" type = "text" id="input"></td>
</tr>
<tr>
<td colspan = "" align = "center"><input name="submit" type = "submit" value = "確定">
<input name="reset" type = "reset" value = "取消">
</td>
</tr>
<tr>
<td colspan = "" align = "center">消息提示
<%
//判斷:
if(!regex(name)){
outprint("用戶名只能是azAZ的字符");
return;//跳出程序只行
}

outprint("恭喜您的數據錄入合法了<br>"+"您錄入的名字是"+name+"<br>您錄入的密碼是"+pass);

%>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>

From:http://tw.wingwit.com/Article/program/Java/JSP/201311/20024.html