这个思路的逻辑是这样的。后台的Filter过滤掉恶意注入代码的话，抛出RuntimeException()，然后导致ajax请求失败，然后回调ajax请求的error方法。但是我们错误页面的数据怎么传送过去呢？经过我认真思考之后，我们可以这样做，在session存一个error_messgae值，然后ajax请求的error方法跳转到错误页面，然后进行取值渲染错误页面。
ajax请求
$.ajax({ method:'post', url:'servlet/DemoServlet', dataType:'json', data:{ 'userName':userName, 'passWord':passWord, 'text': text }, success:function(data){ //成功之后的逻辑 }, error:function(){ window.location.href="error.jsp"; } });
防止SQL注入Filter
package com.yiyexiaoyuan.filter; import java.io.IOException; import java.util.Enumeration; import javax.security.auth.message.callback.PrivateKeyCallback.Request; 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; import net.sf.json.JSONObject; //过滤sql关键字的Filter public class SQLFilter implements Filter { public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse res = (HttpServletResponse) response; // 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 (int i = 0; i < value.length; i++) { sql = sql + value[i]; } } System.out.println("提交方式:"+req.getMethod()); System.out.println("被匹配字符串：" + sql); if (sqlValidate(sql)) { req.getSession().setAttribute("error_message","恶意注入了"); throw new RuntimeException("恶意注入"); } else { String request_uri = req.getRequestURI(); chain.doFilter(request, response); } } // 校验 protected static boolean sqlValidate(String str) { str = str.toLowerCase();// 统一转为小写 // String badStr = "and|exec"; 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|//|/|%|#"; */// 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++) { if (str.indexOf(badStrs[i]) != -1) { System.out.println("匹配到：" + badStrs[i]); 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."); } }
error.jsp实现