1.我为什么用JRebel ? Becuase Spring-Loaded 1.2.3 can't reload classes packaged in JAR files. This is coming in the next release, 1.2.4. 即Spring-Loaded 1.2.3不支持reload jar,而这个特性是我最关心的2.JRebel在eclipse reload class的话和spring-loaded基本一致,可参考我写的这篇文章:http://www.blogjava.net/landon/archive/2015/06/19/425797.html VmArguments: -agentpath:C:\Users\pc\Desktop\jrebel-6.2.0-crack\lib\jrebel64.dll -noverify 注:1.本人用的是6.2.0的破解版本,如何获取该版本,我不予置评。 2.对于-javaagent模式,我本地测试并卵,所以用了-agentpath模式,测试Ok.3.如何确定JRebel启动成功并reload了classes 这是我在eclipse中测试的一个输出: 六月 26, 2015 10:40:26 上午 java.util.prefs.WindowsPreferences <init> WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx() returned error code 5. 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: ############################################################# 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: JRebel Agent 6.2.0 (201505201205) 2015-06-26 10:40:29 JRebel: (c) Copyright ZeroTurnaround AS, Estonia, Tartu. 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: Over the last 1 days JRebel prevented 2015-06-26 10:40:29 JRebel: at least 1 redeploys/restarts saving you about 0 hours. 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: Licensed to anonymous-user 2015-06-26 10:40:29 JRebel: with the following restrictions: 2015-06-26 10:40:29 JRebel: ####### Cracked by anonymous-user, For FUN! Unlimited! Enjoy! ###### 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: License type: perpetual 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: ############################################################# 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: 2015-06-26 10:40:29 JRebel: A newer version '6.2.1' is available for download 2015-06-26 10:40:29 JRebel: from http://zeroturnaround.com/software/jrebel/download/
2015-06-26 10:40:29 JRebel: reload reload reload reload reload reload reload 2015-06-26 10:40:49 JRebel: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx() returned error code 5. reload 2015-06-26 10:40:51 JRebel: Reloading class 'com.mavsplus.example.springloaded.Reload'. load load load 4.JRebel如何reload classes in jar ? 这个是我关心的重点,因为我做的是游戏服务器开发,线上部署的通常是一个jar,然后指定jvm参数,脚本启动。如线上可以分为一个mainLaunch.jar,一个reloadLogic.jar,后者jar为可reload的逻辑代码。那么问题就是线上如果需要更新reloadLogic.jar,怎么办?用JRebel. 1. startup.bat 启动脚本(脱离eclipse)@echo off
cd /d %~dp0
java -Drebel.dirs=E:\mavsplus\reload\classes
-Drebel.log=true
-agentpath:C:\Users\pc\Desktop\jrebel-6.2.0-crack\lib\jrebel64.dll
-noverify
-cp mainLaunch.jar;reloadLogic.jar com.mavsplus.example.jrebel.JRebelExample
-Drebel.dirs用来指定Jrebel监视reloadLogic.jar的class变化,即如果我们线上想更新reloadLogic.jar时,可以打包新的reloadLogic.jar->上传到该目录->解压->classes至该目录 -->该目录发生变化,则线上reloadLogic.jar的业务也会马上变化5.JRebel是否可用于线上生产环境? 1.引用JRebelWhitePaper2014.pdf的一段话: JRebel is a –javaagent plugin for the JVM. It's a downloadable .jar file, available as a standalone .zip distribution or as an IDE plugin for Eclipse, IntelliJ IDEA or NetBeans IDE. 【JRebel will cause around 10-15% performance overhead, however during development this is more or less unnoticeable, unlike in the production environment.】 即JRebel会有很大的性能损失,所以不建议生产环境使用,只建议开发环境,方便部署和调试。 2.那么我就想用JRebel在线上生产环境怎么办? zeroturnaround公司之前还有一个产品叫做liverebel,可用于线上环境。但是由于未能引起足够的消费者关注,所以在2014年11月也停止了。。。 3.其实JRebel和Spring-Loaded就是一个开发环境下的利器,skip build and redeploy process,大大提升了工作效率!而非生产环境的利器。。。因为线上reload本来风险就很大。6. 其他相关 1. https://docs.oracle.com/javase/8/docs/technotes/guides/jpda/ 2. https://wikis.oracle.com/display/mlvm/HotSwap 3. http://www.hotswapagent.org/ 4. https://github.com/dcevm/dcevm7.后续 我会继续研究Java的HotSwap/HotDeploy/HotReplace/OSGI等
posted on 2015-06-26 18:48
landon 阅读(4663)
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