Java Web项目解决 sql 注入问题（过滤器进行过滤解决）

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1、编写过滤器类—SqlFilter.java

**

package com.yl.zp.controller;

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;

import org.springframework.stereotype.Component;

@Component
public class SqlFilter implements Filter {

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO 自动生成的方法存根
		
	}

	@Override
	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("被匹配字符串："+sql);  
        if (sqlValidate(sql)) {  
            //res.sendRedirect("error.jsp");  
            System.out.println("发现sql注入。。。。。。。");
        } else {  
            chain.doFilter(req, res);  
        }
		
	}

	@Override
	public void destroy() {
		// TODO 自动生成的方法存根
		
	}
	
	//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|-|--|+|,|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;  
    } 

}

**

2、在 web.xml 中配置过滤器

**

<filter>
    <filter-name>SqlFilter</filter-name>
    <filter-class>com.yl.zp.controller.SqlFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>SqlFilter</filter-name>
    <url-pattern>/*
  

这样就可以了，这样的配置会拦截所有的请求，对请求中的参数进行检验。

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