在 JNA 中加载 DLL 时找不到指定的模块

Question

我有这个 class 初始化程序：

System.setProperty("java.library.path", "C:\Users\lucas\Desktop\libraries");
System.loadLibrary("libTTARCHHelper");
TTARCH_LIBRARY=(TtarchLibrary)Native.loadLibrary(TtarchLibrary.class);

并且DLL位于C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll

如果我在 Eclipse 中运行我得到 'The specified module could not be found' 如果我运行它作为一个 JAR 我得到 'no libTTARCHHelper in java.library.path'.

我该如何解决这些问题？我什至尝试将 DLL 放在 PATH 环境变量的文件夹中。

使用文件直接加载进行完整调试：

Aug 26, 2020 12:28:51 AM com.sun.jna.Native extractFromResourcePath
INFO: Looking in classpath from jdk.internal.loader.ClassLoaders$AppClassLoader@c387f44 for /com/sun/jna/win32-x86-64/jnidispatch.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.Native extractFromResourcePath
INFO: Found library resource at jar:file:/C:/Users/lucas/Desktop/My%20Stuff/Eclipse%20Workspaces/Build%20Paths/jna-5.6.0.jar!/com/sun/jna/win32-x86-64/jnidispatch.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.Native extractFromResourcePath
INFO: Extracting library to C:\Users\lucas\AppData\Local\Temp\jna-103324076\jna5931694657592960137.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Looking for library 'C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll'
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Adding paths from jna.library.path: null
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Trying C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Loading failed with message: The specified module could not be found.

Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Adding system paths: []
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Trying C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Loading failed with message: The specified module could not be found.

Aug 26, 2020 12:28:51 AM com.sun.jna.Native extractFromResourcePath
INFO: Looking in classpath from jdk.internal.loader.ClassLoaders$AppClassLoader@c387f44 for C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll
Aug 26, 2020 12:28:51 AM com.sun.jna.NativeLibrary loadLibrary
INFO: Loading failed with message: Native library (win32-x86-64/C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll) not found in resource path (C:\Users\lucas\eclipse-workspace\TEST\bin;C:\Users\lucas\Desktop\My Stuff\Eclipse Workspaces\Build Paths\jna-5.6.0.jar)
Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable to load library 'C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll':
The specified module could not be found.

The specified module could not be found.

跟踪的其余部分：

Native library (win32-x86-64/C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll) not found in resource path (C:\Users\lucas\eclipse-workspace\TEST\bin;C:\Users\lucas\Desktop\My Stuff\Eclipse Workspaces\Build Paths\jna-5.6.0.jar)
    at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:301)
    at com.sun.jna.NativeLibrary.getInstance(NativeLibrary.java:461)
    at com.sun.jna.Library$Handler.<init>(Library.java:192)
    at com.sun.jna.Native.loadLibrary(Native.java:646)
    at com.sun.jna.Native.loadLibrary(Native.java:630)
    at com.test.TTARCHHelper.<clinit>(TTARCHHelper.java:17)
    at com.test.main.main(main.java:6)
    Suppressed: java.lang.UnsatisfiedLinkError: The specified module could not be found.

        at com.sun.jna.Native.open(Native Method)
        at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:191)
        ... 6 more
    Suppressed: java.lang.UnsatisfiedLinkError: The specified module could not be found.

        at com.sun.jna.Native.open(Native Method)
        at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:204)
        ... 6 more
    Suppressed: java.io.IOException: Native library (win32-x86-64/C:\Users\lucas\Desktop\libraries\libTTARCHHelper.dll) not found in resource path (C:\Users\lucas\eclipse-workspace\TEST\bin;C:\Users\lucas\Desktop\My Stuff\Eclipse Workspaces\Build Paths\jna-5.6.0.jar)
        at com.sun.jna.Native.extractFromResourcePath(Native.java:1095)
        at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:275)
        ... 6 more

所以看起来它没有找到它，它抛出一个

java.lang.UnsatisfiedLinkError: The specified module could not be found.

我发现了问题，DLL 是针对错误位的。 Eclipse 运行s on 64 和 JAR 使用 32 位 JVM。我也下载了 32 位 dll，现在当我运行 JAR 时它可以工作。然而，Eclipse 中的 64 位 dll 不断抛出上述模块异常

Answer 1

JNA 将在 jna.library.path 环境变量中的位置查找库。

一个选项是在 Eclipse 的运行配置中将其指定为命令行选项。在运行菜单中，select运行配置。转到 (x)=Arguments 选项卡。在 VM 参数字段中添加：

-Djna.library.path=C:\Users\lucas\Desktop\libraries

您还可以在尝试加载 DLL 之前以编程方式在代码中设置它：

System.setProperty("jna.library.path", "C:\Users\lucas\Desktop\libraries");

正如您稍后在调试日志中指出的那样，它可能找到了 DLL 但无法打开它。可能的原因可能是：

DLL runtime-dependent 在您系统上的另一个 DLL 上，该 DLL 不在适当的路径中。一个常见的是 Visual C++ Distributable。您可能需要查阅 DLL 文档以获取更多信息。您有时可以使用 SysInternals 库中的 Process Monitor 来尝试查看打开的内容。
具有上述依赖 DLL 的 duplicate/incompatible 版本
运行正在运行 64 位 JVM 并尝试打开与 64 位不兼容的 DLL，或者 vice-versa
您的 Java 程序可能没有权限读取您的库所在的目录

为了帮助诊断问题，请查看完整的堆栈跟踪。虽然最近的错误消息可能不相关（在“备份”搜索中找不到文件），但如果您查看跟踪，您可能会看到早期尝试打开 DLL 时出现的多个被抑制的异常，这可能会为您提供更多有用的调试信息。

在 JNA 中加载 DLL 时找不到指定的模块

Specified module could not being found loading DLL in JNA

java

jna