适用于出现以下问题：

1、SQL盲注

2、存储的跨站点脚本编制 或 跨站点脚本编制

import java.io.IOException;

import java.util.Enumeration;

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;

public class AntiSqlInjectionfilter implements Filter {

public void destroy() {

// TODO Auto-generated method stub

}

public void init(FilterConfig arg0) throws ServletException {

// TODO Auto-generated method stub

}

public void doFilter(ServletRequest args0, ServletResponse args1,

FilterChain chain) throws IOException, ServletException {

HttpServletRequest req=(HttpServletRequest)args0;

HttpServletResponse res=(HttpServletResponse)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 (int i = 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)) {

throw new IOException("您发送请求中的参数中含有非法字符："+sql);

//String ip = req.getRemoteAddr();

} else {

chain.doFilter(args0,args1);

}

}

//效验

protected static boolean sqlValidate(String str) {

str = str.toLowerCase();//统一转为小写

String badStr = "'|select|update|and|or|delete|insert|truncate|char|into"

+ "|substr|declare|exec|master|drop|execute|"

+ "union|;|--|+|,|like|//|/|%|#|*|$|@|\"|http|cr|lf||(|)";//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]) >= 0) {

return true;

}

}

return false;

}

}