Struts2学习4——防sql注入过滤器

web.xml

    <!-- sql Filter -->     <filter>        <filter-name>SqlFilter</filter-name>        <filter-class>Utils.SqlFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>SqlFilter</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>

Utils.SqlFilter

package Utils;import java.io.IOException;import java.util.Enumeration;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;import javax.servlet.http.HttpServletResponse;//过滤sql关键字的Filterpublic class SqlFilter implements Filter {    public void doFilter(ServletRequest request, ServletResponse response,            FilterChain chain) throws IOException, ServletException {        HttpServletRequest req = (HttpServletRequest) request;        HttpServletResponse res = (HttpServletResponse) response;        // 获得所有请求参数名        Enumeration<?> params = req.getParameterNames();        String sql = "";        while (params.hasMoreElements()) {            // 得到参数名            String name = params.nextElement().toString();            // System.out.println("name===========================" + name +            // "--");            // 得到参数对应值            String[] value = req.getParameterValues(name);            for (int i = 0; i < value.length; i++) {                sql = sql + value[i];            }        }        //System.out.println("被匹配字符串：" + sql);        if (sqlValidate(sql)) {            res.sendRedirect("/error.jsp");        } else {            chain.doFilter(req, res);        }    }    // 校验    protected static boolean sqlValidate(String str) {        str = str.toLowerCase();// 统一转为小写        // String badStr = "and|exec";        String badStr = "'|and|exec|execute|insert|select|delete|update|count|drop|chr|mid|master|truncate|char|declare|sitename|net user|xp_cmdshell|or|like";        /*         * String badStr =         * "'|and|exec|execute|insert|create|drop|table|from|grant|use|group_concat|column_name|"         * +         * "information_schema.columns|table_schema|union|where|select|delete|update|order|by|count|*|"         * + "chr|mid|master|truncate|char|declare|or|;|-|--|+|,|like|//|/|%|#";         */// 过滤掉的sql关键字，可以手动添加        String[] badStrs = badStr.split("\\|");        for (int i = 0; i < badStrs.length; i++) {            if (str.indexOf(badStrs[i]) != -1) {                System.out.println("匹配到：" + badStrs[i]);                return true;            }        }        return false;    }    public void init(FilterConfig filterConfig) throws ServletException {        // throw new UnsupportedOperationException("Not supported yet.");    }    public void destroy() {        // throw new UnsupportedOperationException("Not supported yet.");    }}

另外程序代码中避免字符串拼接，使用PreparedStatement。

原文参考：
http://blog.csdn.net/u012377333/article/details/51535483