sun.zip.disableMemoryMapping__開源項目(Open

有時候你如果修改了JVM正在load的jar檔案，會導致JVM crash。stacktrace是在java.util.zip.ZipFile.getEntry() 時發生的。

There are three possible scenarios here:
1. While a class is in use it is dynamically reloaded from a jar file.
2. While a jar file is being accessed by the class loader, the jar file is being modified.
3. A Jarfile which was bigger than 4GB was accessed (applies to Java 6 and earlier only)

那麼解決辦法就是要確保當JVM在裝載jar檔案的時候，jar檔案不要被其它程式更新或者修改。後來JVM就引入了一個新的性質sun.zip.disableMemoryMapping，如果在JVM啟動時加上參數-Dsun.zip.disableMemoryMapping=true，然後JVM在遇到這種情況下的時候就不crash。

當然不能過度依賴這個性質，因為jar檔案在被load的時候被更新可能會導致程式執行異常，更容易出bug等問題。

原文:http://blog.csdn.net/hongchangfirst/article/details/78950369

作者:hongchangfirst

hongchangfirst的首頁:http://blog.csdn.net/hongchangfirst