XSS : 跨站脚本攻击(Cross Site Scripting)，为不和层叠样式表(Cascading Style Sheets, CSS)的缩写混淆，故将跨站脚本攻击缩写为XSS。恶意攻击者往Web页面里插入恶意html代码，当用户浏览该页之时，嵌入其中Web里面的html代码会被执行，从而达到恶意攻击用户的特殊目的。

sql注入

所谓SQL注入，就是通过把SQL命令插入到Web表单提交或输入域名或页面请求的查询字符串，最终达到欺骗服务器执行恶意的SQL命令。具体来说，它是利用现有应用程序，将（恶意）的SQL命令注入到后台数据库引擎执行的能力，它可以通过在Web表单中输入（恶意）SQL语句得到一个存在安全漏洞的网站上的数据库，而不是按照设计者意图去执行SQL语句。

1、首先配置web.xml，添加如下配置信息：

xssAndSqlFilter

com.cup.cms.web.framework.filter.XssAndSqlFilter

xssAndSqlFilter

*

2、编写过滤器

/**

*

*/

package com.cup.cms.web.framework.filter;

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

/**

* @Author hithedy

* @Date 2016年2月2日

* @Time 下午2:01:53

*/

public class XssAndSqlFilter implements Filter {

@Override

public void destroy() {

// TODO Auto-generated method stub

}

@Override

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

XssAndSqlHttpServletRequestWrapper xssRequest = new XssAndSqlHttpServletRequestWrapper((HttpServletRequest) request);

chain.doFilter(xssRequest, response);

}

@Override

public void init(FilterConfig arg0) throws ServletException {

// TODO Auto-generated method stub

}

}

3、包装器

/**

*

*/

package com.cup.cms.web.framework.filter;

import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletRequestWrapper;

/**

* @Author hithedy

* @Date 2016年2月2日

* @Time 下午2:03:19

*/

public class XssAndSqlHttpServletRequestWrapper extends HttpServletRequestWrapper {

HttpServletRequest orgRequest = null;

public XssAndSqlHttpServletRequestWrapper(HttpServletRequest request) {

super(request);

orgRequest = request;

}

/**

* 覆盖getParameter方法，将参数名和参数值都做xss & sql过滤。

* 如果需要获得原始的值，则通过super.getParameterValues(name)来获取

* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖

*/

@Override

public String getParameter(String name) {

String value = super.getParameter(xssEncode(name));

if (value != null) {

value = xssEncode(value);

}

return value;

}

/**

* 覆盖getHeader方法，将参数名和参数值都做xss & sql过滤。

* 如果需要获得原始的值，则通过super.getHeaders(name)来获取

* getHeaderNames 也可能需要覆盖

*/

@Override

public String getHeader(String name) {

String value = super.getHeader(xssEncode(name));

if (value != null) {

value = xssEncode(value);

}

return value;

}

/**

* 将容易引起xss & sql漏洞的半角字符直接替换成全角字符

*

* @param s

* @return

*/

private static String xssEncode(String s) {

if (s == null || s.isEmpty()) {

return s;

}else{

s = stripXSSAndSql(s);

}

StringBuilder sb = new StringBuilder(s.length() + 16);

for (int i = 0; i

':

sb.append("＞");// 转义大于号

break;

case '<':

sb.append("＜");// 转义小于号

break;

case '\'':

sb.append("＇");// 转义单引号

break;

case '\"':

sb.append("＂");// 转义双引号

break;

case '&':

sb.append("＆");// 转义&

break;

case '#':

sb.append("＃");// 转义#

break;

default:

sb.append(c);

break;

}

}

return sb.toString();

}

/**

* 获取最原始的request

*

* @return

*/

public HttpServletRequest getOrgRequest() {

return orgRequest;

}

/**

* 获取最原始的request的静态方法

*

* @return

*/

public static HttpServletRequest getOrgRequest(HttpServletRequest req) {

if (req instanceof XssAndSqlHttpServletRequestWrapper) {

return ((XssAndSqlHttpServletRequestWrapper) req).getOrgRequest();

}

return req;

}

/**

*

* 防止xss跨脚本攻击（替换，根据实际情况调整）

*/

public static String stripXSSAndSql(String value) {

if (value != null) {

// NOTE: It's highly recommended to use the ESAPI library and

// uncomment the following line to

// avoid encoded attacks.

// value = ESAPI.encoder().canonicalize(value);

// Avoid null characters

/**value = value.replaceAll("", "");***/

// Avoid anything between script tags

Pattern scriptPattern = Pattern.compile("

(.*?)

", Pattern.CASE_INSENSITIVE);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid anything in a src="http://www.yihaomen.com/article/java/..." type of e-xpression

scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

value = scriptPattern.matcher(value).replaceAll("");

// Remove any lonesome

tag

scriptPattern = Pattern.compile("

", Pattern.CASE_INSENSITIVE);

value = scriptPattern.matcher(value).replaceAll("");

// Remove any lonesome

tag

scriptPattern = Pattern.compile("

", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid eval(...) expressions

scriptPattern = Pattern.compile("eval\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid e-xpression(...) expressions

scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid javascript:... expressions

scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid vbscript:... expressions

scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);

value = scriptPattern.matcher(value).replaceAll("");

// Avoid onload= expressions

scriptPattern = Pattern.compile("onload(.*?)=", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

value = scriptPattern.matcher(value).replaceAll("");

}

return value;

}

}

能够防止常见的XSS和SQL注入。