关于 sql 注入的简单过滤

/**

• SQL 过滤

*/
public class SQLFilter {

/**
 * SQL注入过滤
 * @param str  待验证的字符串
 */
public static String sqlInject(String str){
    if(StringUtils.isBlank(str)){
        return null;
    }
    //去掉'|"|;|\字符
    str = StringUtils.replace(str, "'", "");
    str = StringUtils.replace(str, "\"", "");
    str = StringUtils.replace(str, ";", "");
    str = StringUtils.replace(str, "\\", "");

    //转换成小写
    str = str.toLowerCase();

    //非法字符
    String[] keywords = {"master", "truncate", "insert", "select", "delete", "update", "declare", "alert", "drop"};

    //判断是否包含非法字符
    for(String keyword : keywords){
        if(str.indexOf(keyword) != -1){
            throw new RRException("包含非法字符");
        }
    }

    return str;
}

}