web项目过滤掉非法字符串

在项目中，会遇到关于sql注入，以及跨站脚本，XSS，链接注入等攻击，这里就需要做一些验证，当时接到这个需求，在网上查找了半天终于找到一篇文章，并拿来测试，但是，这个里面是有一些错误的。

package com.cn.util;
 
import java.io.IOException;
import java.io.PrintWriter;
 
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;
 
/**
 *
 * @ClassName: IllegalCharacter
 * @Description: 此模块用于非法字符验证
 * @author huxd
 * @date 2017年3月26日 下午12:07:28
 *
 */
public class IllegalCharacter implements Filter{
     private String[] characterParams = null;
     private boolean OK=true;
     public void destroy() {
     }
     /**
      * 此程序块主要用来解决参数带非法字符等过滤功能
      */
     public void doFilter(ServletRequest request, ServletResponse response,
       FilterChain arg2) throws IOException, ServletException {
      
      HttpServletRequest servletrequest = (HttpServletRequest) request;
      HttpServletResponse servletresponse = (HttpServletResponse) response;
      boolean status = false; 
       java.util.Enumeration params = request.getParameterNames();
       String param="";
       String paramValue = "";
       servletresponse.setContentType("text/html");
       servletresponse.setCharacterEncoding("utf-8");
       while (params.hasMoreElements()) {
        param = (String) params.nextElement();<br>　　　　　　　// 这里原代码是用的   String[] 接的数据，这样会造成一些非法字符  <，> 等，这些都是无法转换的！造成是空，这个坑了我2个小时才找到
        String values = request.getParameter(param);
            paramValue = "";
            if(OK){//过滤字符串为0个时 不对字符过滤
                paramValue=paramValue+values;
            for(int i=0;i<characterParams.length;i++)
             if (paramValue.indexOf(characterParams[i]) >= 0) {
              status = true;
              break;
             }
            if(status)break;
            }
           }
           if (status) {
            PrintWriter out = servletresponse.getWriter();
            out
              .print("<script language='javascript'>alert(\"您提交的相关表单数据字符含有非法字符。如：\\\"'\\\".\");location.href('"
                + servletrequest.getRequestURL()
                + "');</script>");
           }else
           arg2.doFilter(request, response);
         }
     public void init(FilterConfig config) throws ServletException {
      if(config.getInitParameter("characterParams").length()<1)
       OK=false;
      else
      this.characterParams = config.getInitParameter("characterParams").split(",");
     }
}

web.xml配置

!-- 跨域脚本攻击防御 -->
   <!-- 非法字符过滤器 -->
   <filter>
    <filter-name>IllegalCharacter</filter-name>
    <filter-class>com.cn.util.IllegalCharacter</filter-class>
    <init-param>
     <param-name>characterParams</param-name>
     <param-value><,>,;,",”,“,*,@,IMG,SRC,$,@,',",|,>,+,CR,LF</param-value><!-- 此处加入要过滤的字符或字符串，以逗号隔开 -->
    </init-param>
   </filter>
   <filter-mapping>
    <filter-name>IllegalCharacter</filter-name>
    <url-pattern>/*</url-pattern>
   </filter-mapping>

web项目过滤掉非法字符串

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