java类防止sql注入

packagecom.tarena.dingdang.filter;

 

importjava.io.IOException;

importjava.util.Enumeration;

 

importjavax.servlet.Filter;

importjavax.servlet.FilterChain;

importjavax.servlet.FilterConfig;

importjavax.servlet.ServletException;

importjavax.servlet.ServletRequest;

importjavax.servlet.ServletResponse;

importjavax.servlet.http.HttpServletRequest;

 

publicclass AntiSqlInjectionfilter implementsFilter {

 

    publicvoid destroy() {

        // TODO Auto-generated method stub

    }

     

    publicvoid init(FilterConfig arg0) throwsServletException {

        // TODO Auto-generated method stub

    }

     

    publicvoid doFilter(ServletRequest args0, ServletResponse args1,

            FilterChain chain) throwsIOException, ServletException {

        HttpServletRequest req=(HttpServletRequest)args0;

        HttpServletRequest res=(HttpServletRequest)args1;

         //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(inti = 0; i < value.length; i++) {

                sql = sql + value[i];

            }

        }

        //System.out.println("============================SQL"+sql);

        //有sql关键字，跳转到error.html

        if(sqlValidate(sql)) {

            thrownew IOException("您发送请求中的参数中含有非法字符");

            //String ip = req.getRemoteAddr();

        }else{

            chain.doFilter(args0,args1);

        }

    }

     

    //效验

    protectedstatic 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(inti = 0; i < badStrs.length; i++) {

            if(str.indexOf(badStrs[i]) >= 0) {

                returntrue;

            }

        }

        returnfalse;

    }

}

 

 

<!--在web.xml文件中的配置-->

<!-- 防止SQL注入的过滤器 -->

    <filter>

        <filter-name>antiSqlInjection</filter-name>

        <filter-class>com.tarena.dingdang.filter.AntiSqlInjectionfilter</filter-class>

    </filter>

    <filter-mapping>

        <filter-name>antiSqlInjection</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>