防止Sql注入拦截

这两天在做一个sql注入拦截，期间遇到了不少问题，最大的问题是在，拦截sql注入后利用response 重定向到错误页面，始终无法实现跳转。发现原因是，ajax 异步请求时并不会对response重定向做处理。当然包括response.getWrite().print(“”);等页面都不会做出反应。

下面是我的代码，首先是编写一个拦截器
package com.booway.pwbzh.util;

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;

/**
* sql注入攻击拦截
* @author s
*/
public class SqlInjectFilter implements Filter
{
FilterConfig filterConfig = null;

/**
 * 初始化
 * @param filterConfig filterConfig
 * @throws ServletException 异常
 */
public void init(FilterConfig filterConfig) throws ServletException
{
    this.filterConfig = filterConfig;
}

public void destroy()
{
    this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
{
    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;
    try
    {
        // 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();
            // 得到参数对应值
            String[] value = req.getParameterValues(name);
            for (int i = 0; i < value.length; i++)
            {
                sql = sql + value[i];
            }
        }
        // 截取我要拦截的字段
        sql = getfilte(sql);
        // 有sql关键字，跳转到error.html
        if (sqlValidate(sql))
        {
            res.setHeader("SESSIONSTATUS", "TIMEOUT");
            res.setHeader("CONTEXTPATH", req.getContextPath() + "/pwbzh_module/500.jsp");
            res.setStatus(HttpServletResponse.SC_FORBIDDEN);
            return;
            // throw new IOException("您发送请求中的参数中含有非法字符");

        }

        chain.doFilter(request, response);
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }

}

// 效验
protected static boolean sqlValidate(String str)
{
    str = str.toLowerCase();// 统一转为小写
    String badStr = "'|and|exec|execute|insert|select|delete|update|count|drop|*|%|chr|mid|master|truncate|" + "char|declare|sitename|net user|xp_cmdshell|;|or|-|+|,|like'|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++)
    {
        // 循环检测，判断在请求参数当中是否包含SQL关键字
        if (str.indexOf(badStrs[i]) >= 0)
        {
            return true;
        }
    }
    return false;
}

// 截取需要拦截的字段
protected static String getfilte(String str)
{
    int idex = str.indexOf("filter");
    String ss = "";
    if (idex < 0)
    {
        return ss;
    }
    if (str.indexOf(",", idex) < 0)
    {
        ss = str.substring(idex, str.length());
    }
    else
    {
        ss = str.substring(idex, str.indexOf(",", idex));
    }
    return ss;
}

}
在xml中加入拦截配置

SqlInjectFilter

com.booway.pwbzh.util.SqlInjectFilter

/

解决方案出自 http://blog.csdn.net/guiyingde/article/details/53381734