前言：
在一些业务需求中有的是只能当前主机登录熊系统，或者说是当前的网段内用户可以访问，这时候就需要用到了servlet中的过滤器了。
放行指定IP：
编写过滤器：
package com.mixky.app.bjcc.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
/**
* @author zhangzhixi
* @version 1.0
* @date 2021-8-16 16:38
*/
public class NoteFilter implements Filter {
private FilterConfig config = null;
//ip白名单
private String ipTable = null;
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("note filter initial");
this.config = filterConfig;
/*获取白名单*/
this.ipTable = config.getInitParameter("ipTable");
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
System.out.println("do filter starting");
/*校验ip地址：不是白名单就直接结束*/
if (!verifyIP(request, response)) {
return;
}
long befor = System.currentTimeMillis();
config.getServletContext().log("before call note Filter");
chain.doFilter(request, response);
config.getServletContext().log("after call note Filter");
long after = System.currentTimeMillis();
String name = "";
if (request instanceof HttpServletRequest) {
name = ((HttpServletRequest) request).getRequestURI();
}
config.getServletContext().log("Note Filter : name:" + name + " time :" + (after - befor) + "ms");
}
@Override
public void destroy() {
}
/**
* 验证IP
*
* @param request 请求
* @param response 响应
* @return 校验结果
*/
private boolean verifyIP(ServletRequest request, ServletResponse response) {
/*获取本机IP地址*/
String ip = request.getLocalAddr();
/*windows下本机测试*/
if ("0:0:0:0:0:0:0:1".equals(ip)) {
ip = "127.0.0.1";
System.out.println("请求ip:" + ip);
}
System.out.println("本机IP是：" + ip);
System.out.println("ipTable白名单:" + ipTable);
/*是白名单用户*/
if (ipTable.equals(ip)) {
return true;
} else {
System.out.println("校验不通过");
/*设置编码*/
try {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = null;
try {
out = response.getWriter();
out.print("<h1>对不起，你的ip不能访问服务器</h1>");
out.flush();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return false;
}
}
}
web.xml配置文件：
<!--IP过滤--> <filter> <filter-name>ip</filter-name> <filter-class>com.mixky.app.bjcc.filter.NoteFilter</filter-class> <init-param> <param-name>ipTable</param-name> <!--设置的白名单IP--> <param-value>127.0.0.1</param-value> </init-param> </filter> <filter-mapping> <filter-name>ip</filter-name> <!--过滤所有请求--> <url-pattern>/*</url-pattern> </filter-mapping>