技術標籤：問題集用過濾器防sql注入防sql注入過濾器解決sql注入

使用過濾器是解決sql注入的一種方式，其它可以前端校驗處理等

過濾器寫法：

package XXX.utils;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Enumeration;

/**
 * sql注入過濾器
 * @Date 2020/12/24
 **/
public class SqlInjectionFilter implements Filter{

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

        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
        //獲得所有請求引數名
        Enumeration params = req.getParameterNames();

        String sql = "";
        while (params.hasMoreElements()) {
            //得到引數名
            String name = params.nextElement().toString();
            //System.out.println("name===========================" + name + "--");
            //得到引數對應值
            String[] value = req.getParameterValues(name);
            for (int i = 0; i < value.length; i++) {
                sql = sql + value[i];
            }
        }
        //System.out.println("============================SQL"+sql);
        //有sql關鍵字，跳轉到error.html
        if (sqlValidate(sql)) {
            throw new IOException("您傳送請求中的引數中含有非法字元");
        } else {
            chain.doFilter(req, res);
        }
    }

    //效驗
    protected static boolean sqlValidate(String str) {
        str = str.toLowerCase();//統一轉為小寫
        //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|//|/|%|#";//過濾掉的sql關鍵字，可以手動新增
        String[] badStrs = badStr.split("\\|");
        for (int i = 0; i < badStrs.length; i++) {
            if (str.indexOf(badStrs[i]) !=-1) {
                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.");
    }

}
 

web.xml中做配置

 <filter>
    <filter-name>SqlInjectionFilter</filter-name>
    <filter-class>com.hnac.hzinfo.common.utils.SqlInjectionFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>SqlInjectionFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>