关于 android dalvik-cache 含义

dalvik-cache 为android 系统目录下：data/ dalvik-cache :

该目录的定义为：

Dalvik Cache, is a temporary space used by the Java virtual machine to run Android applications. - See more at: http://www.blogsolute.com/dalvik-cache-clear-free-space/713/#sthash.hlrysOnc.dpuf

Dalvik Cache, is a temporary space used by the Java virtual machine to run Android applications. - See more at: http://www.blogsolute.com/dalvik-cache-clear-free-space/713/#sthash.hlrysOnc.dpuf

Dalvik Cache, is a temporary space used by the Java virtual machine to run Android applications. - See more at: http://www.blogsolute.com/dalvik-cache-clear-free-space/713/#sthash.hlrysOnc.dpuf

Dalvik Cache, is a temporary space used by the Java virtual machine to run Android applications.

Dalvik is the virtual machine that is used by Android. It is generally thought of as a java virtual machine, although this is not precisely correct. It uses an object model that is identical to java, and it's memory model is also nearly equivalent. But the

dalvik VM is a register based VM, as opposed to java VMs, which are stack based.

Accordingly, it uses a completely different bytecode than java. However, the Android SDK includes thedx tool to translate java bytecode to dalvik bytecode, which is why you are able to write Android applications in java.

When you say "dalvik-cache", I assume you mean the /data/dalvik-cache directory that can be found on typical Android devices. When you install an application on Android, it performs some modifications and optimizations on that application's

dex file (the file that contains all the dalvik bytecode for the application). It then caches the resulting odex (optimized dex) file in the/data/dalvik-cache directory,

对应地址：http://stackoverflow.com/questions/7541281/what-is-dalvik-and-dalvik-cache

刷rom时需要删除dalvik-cache目录下：对应 http://android.stackexchange.com/questions/25859/why-do-i-need-to-wipe-dalvik-cache

发现应用安装时 会在 该目录下重新更新新的dex 文件；

应用卸载时 会删除对应的dex文件；

如果将该目录下对应的dex文件删除了，发现应用仍然能正常启动使用，但是不会重新生成dex文件；

插件化升级时问题（直接替换apk包，而不安装，则dex文件仍然为旧的）：会因为虚拟机加载的字节码还是旧的导致应用启动失败；