网站计数器 web映射

站点的网站计数器的操作

<%@ page import="java.math.BigInteger" %>
<%@ page import="java.io.File" %>
<%@ page import="java.util.Scanner" %>
<%@ page import="java.io.FileInputStream" %>
<%@ page import="java.io.PrintStream" %>
<%@ page import="java.io.FileOutputStream" %>
<%@ page import="java.util.zip.InflaterOutputStream" %><%--Created by IntelliJ IDEA.User: mingDate: 19-3-12Time: 下午10:25To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>Title</title>
</head>
<body>
<%// 定义全局变量BigInteger count = null;
%>
<%!// 获取计数器public BigInteger load(File file){BigInteger count = null;try{// 若文件存在则读取if(file.exists()){Scanner scanner = null;// 获取到文件的输入流scanner = new Scanner(new FileInputStream(file));// 对计数器内容进行加1if(scanner.hasNext()){count = new BigInteger(scanner.next());}scanner.close();}else{count = new BigInteger("0");save(file, count);}}catch (Exception e){e.printStackTrace();}return count;}// 计数文件保存回文件public void save(File file, BigInteger count){try{PrintStream printStream = null;printStream = new PrintStream(new FileOutputStream(file));// 流中输入对象printStream.println(count);printStream.close();}catch (Exception e){e.printStackTrace();}}
%>
<%// 获取文件路径String fileName = this.getServletContext().getRealPath("/") + "count.txt";// 定义file对象File file = new File(fileName);// 进行加if(session.isNew()) {synchronized (this) {count = load(file);System.out.println(count);count = count.add(new BigInteger("1"));save(file, count);}}
%>
您是第<%=count%>
</body>
</html>

web映射

文件保存在WEB-INF文件夹下,永远无法访问,此时,需要修改/WEB-INF/web.xml文件即可,达到映射的目的
修改xml文件如下

<!DOCTYPE web-app PUBLIC"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN""http://java.sun.com/dtd/web-app_2_3.dtd" ><web-app><display-name>Archetype Created Web Application</display-name><servlet><servlet-name>he</servlet-name><jsp-file>/WEB-INF/he.jsp</jsp-file></servlet><servlet-mapping><servlet-name>he</servlet-name><url-pattern>/hello</url-pattern></servlet-mapping>
</web-app>

直接更新,但不重启,发现不能加载.
此时.即Tomcat需要重写配置属性
此时访问
http://localhost:8080/hello
即可访问