Tomcat

人人都能看懂的 6 种限流实现方案!(纯干货)

淺唱寂寞╮ 提交于 2021-01-27 21:14:13
为了上班方便,去年我把自己在北郊的房子租出去了,搬到了南郊,这样离我上班的地方就近了,它为我节约了很多的时间成本,我可以用它来做很多有意义的事,最起码不会因为堵车而闹心了,幸福感直线上升。 但即使这样,生活也有其他的烦恼。南郊的居住密度比较大,因此停车就成了头痛的事,我租的是路两边的非固定车位,每次只要下班回来,一定是没有车位停了,因此我只能和别人的车并排停着,但这样带来的问题是,我每天早上都要被挪车的电话给叫醒,心情自然就不用说了。 但后来几天,我就慢慢变聪明了,我头天晚上停车的时候,会找第二天限行的车并排停着,这样我第二天就不用挪车了,这真是限行给我带来的“巨大红利”啊。 而 车辆限行就是一种生活中很常见的限流策略 ,他除了给我带来了以上的好处之外,还给我们美好的生活环境带来了一丝改善,并且快速增长的私家车已经给我们的交通带来了巨大的“负担 ” ,如果再不限行,可能所有的车都要被堵在路上,这就是限流给我们的生活带来的巨大好处。 从生活回到程序中,假设一个系统只能为 10W 人提供服务,突然有一天因为某个热点事件,造成了系统短时间内的访问量迅速增加到了 50W,那么导致的直接结果是系统崩溃,任何人都不能用系统了, 显然只有少人数能用远比所有人都不能用更符合我们的预期,因此这个时候我们要使用「限流 」 了 。 限流分类 限流的实现方案有很多种,磊哥这里稍微理了一下, 限流的分类

Java Web Application “Event Listener for Expired Sessions”

时光总嘲笑我的痴心妄想 提交于 2021-01-27 19:31:55
问题 Is there a way to run Java code, after a HttpServletRequest Session expired? If a Session expires, I need to make a DB call. Callback and Listener would be useable. 回答1: javax.servlet.http.HttpSessionListener The Jakarta Servlet specification provides a listener interface for session expiring: HttpSessionListener. You write a class that implements the two methods on that interface. Mark your class with the annotation @WebListener to have your class automatically instantiated by your servlet

Deploying embedded tomcat enabled spring-boot app using IntelliJ

狂风中的少年 提交于 2021-01-27 15:01:30
问题 I have a spring-boot based application, using embedded tomcat. I have no problem when deploying via mvn spring-boot:run goal, but I have a problems when I try to deploy using intelliJ spring-boot plugins. Important note, we have modified the default pom, turning our app into a war that could be deployed into a full tomcatTraditional Deployment, but this in development mode will be better to just deploy the app using the embedded tomcat. The problem is that basically we ended with this message

Deploying embedded tomcat enabled spring-boot app using IntelliJ

北城余情 提交于 2021-01-27 14:34:51
问题 I have a spring-boot based application, using embedded tomcat. I have no problem when deploying via mvn spring-boot:run goal, but I have a problems when I try to deploy using intelliJ spring-boot plugins. Important note, we have modified the default pom, turning our app into a war that could be deployed into a full tomcatTraditional Deployment, but this in development mode will be better to just deploy the app using the embedded tomcat. The problem is that basically we ended with this message

Tomcat behind an apache proxy error on path

夙愿已清 提交于 2021-01-27 13:47:59
问题 I'm trying to configure my apache 2.2 as a proxy to some applications on a server. tomcat-jira : Installed with Jira´s installer; tomcat-dev : Just a container for another applications. First, my httpd.conf is like this: ProxyRequests Off ProxyPreserveHost On <Proxy *> Order deny,allow Allow from all </Proxy> ProxyPass /jira http://dev.debian.local:8080/jira ProxyPassReverse /jira http://dev.debian.local:8080/jira ProxyPass /tomcat http://dev.debian.local:8088 ProxyPassReverse /tomcat http:/

如何简单搭建自己的个人主页

感情迁移 提交于 2021-01-27 12:17:26
首先你需要有一个自己的域名,这个就不多说了,如何拥有自己的域名可以在阿里云或AWS云或者其他云平台购买一个,具体方法必应或者百度一下。 拥有域名后需要添加域名解析地址,解析地址为主机的出口公网ip,如果是物理机则需要在路由器上开启80端口的映射,如果是云主机则需要在安全组里开启80端口放行。selinux关闭,防火墙请开启80端口,如不会直接关闭。 请注意,在国内的服务器请申请备案并把备案号写在网页底部,链接一下。如服务器在国外无需。 下面是具体安装流程 如是初学者请看下面的链接有视频教程感谢这个up主有一定基础的请直接看流程能节省时间 https://www.bilibili.com/video/av15159168/ 首先需要有jdk和tomcat的安装包这个请在jdk和tomacat官网下载必应或者百度开源 下载下来最好是tar的归档文件,通过自己的方法把2个tar包放到/home/pan目录下 pan目录需要自己建立,请一定用root账号登录。 tar命令解包2个文件包,mv jdk* 这里的*表示是jdk的版本到/usr/local目录下 在/home/pan目录下使用mv重命名tomacat解压后的文件夹为 tomcat 接下来就是复杂的配置JDK环境变量环节了,注意不要敲错,vim /etc/profile 打开文件按大写G跳转到末行添加 export JAVA

Access to XMLHttpRequest at '…' from origin 'http://localhost' has been blocked by CORS policy [duplicate]

耗尽温柔 提交于 2021-01-27 07:08:58
问题 This question already has answers here : XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header (10 answers) Closed 1 year ago . I'm trying to demo an api call with javascript to get Json result. Here is what I did: <!DOCTYPE html> <html> <head> </head> <script src="https://canvasjs.com/assets/script/jquery-1.11.1.min.js"></script> <body> <div class="render-form"> <script> $(document).ready(function() { $.ajax({ type: 'GET', headers:{ 'Accept': 'application/json', 'Content

Access to XMLHttpRequest at '…' from origin 'http://localhost' has been blocked by CORS policy [duplicate]

爱⌒轻易说出口 提交于 2021-01-27 07:06:48
问题 This question already has answers here : XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header (10 answers) Closed 1 year ago . I'm trying to demo an api call with javascript to get Json result. Here is what I did: <!DOCTYPE html> <html> <head> </head> <script src="https://canvasjs.com/assets/script/jquery-1.11.1.min.js"></script> <body> <div class="render-form"> <script> $(document).ready(function() { $.ajax({ type: 'GET', headers:{ 'Accept': 'application/json', 'Content

Spring - Thymeleaf - Tomcat -> can not process UTF-8 character correctly

扶醉桌前 提交于 2021-01-27 06:52:41
问题 I am trying to display UTF-8 character in Spring-MVC web page. utf-8 values are coming from the database. I have already converted my database into utf-8. web services I have written is displaying the values as expected but, in the web page it is not showing the correct value. below is my spring configuration, please let me know what I am doing wrong. I am using thymeleaf as a templating engine: Thymeleafe configuration: <bean id="templateResolver" class="org.thymeleaf.templateresolver

Spring - Thymeleaf - Tomcat -> can not process UTF-8 character correctly

家住魔仙堡 提交于 2021-01-27 06:51:09
问题 I am trying to display UTF-8 character in Spring-MVC web page. utf-8 values are coming from the database. I have already converted my database into utf-8. web services I have written is displaying the values as expected but, in the web page it is not showing the correct value. below is my spring configuration, please let me know what I am doing wrong. I am using thymeleaf as a templating engine: Thymeleafe configuration: <bean id="templateResolver" class="org.thymeleaf.templateresolver