Question

从jar文件中提取rxtxSerial.dll时，它会发出此异常

java.lang.NullPointerException
    at org.apache.commons.io.IOUtils.copyLarge(IOUtils.java:1383)
    at org.apache.commons.io.IOUtils.copy(IOUtils.java:1357)
    at weighmentdesk.Weighment.loadJarDll(Weighment.java:940)
    at weighmentdesk.Weighment$5.run(Weighment.java:569)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$000(Unknown Source)
    at java.awt.EventQueue$1.run(Unknown Source)
    at java.awt.EventQueue$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)

我正在使用

找到该文件

getClass().getResourceAsStream("resources\\rxtxSerial.dll")

有什么问题。如果没有，是否有任何替代解决方案将dll文件解压缩到系统根目录（system32）。

提前致谢。

Answer 1

很可能是getClass（）。getResourceAsStream（“resources \ rxtxSerial.dll”）返回null 如果它在jar文件的根目录中，请尝试：

getClass().getResourceAsStream("/rxtxSerial.dll")

如果它位于名为resources的目录下，请尝试：

getClass().getResourceAsStream("/resources/rxtxSerial.dll")

依旧......

从jar文件中获取dll

1 个答案: