Question

我有一个RCP应用程序（称为RCP-APP）。我创建了一个新的插件（称为插件A），它包装了媒体播放器api（.jar文件）和媒体播放器api通过JNA访问的C库（dll）文件夹。然后我创建了另一个插件（称为插件B），其中包含依赖于插件A的媒体播放器应用程序。

当插件B被激活时，我收到以下错误消息，通知我插件B找不到它正在寻找的媒体播放器.dll：

!ENTRY org.eclipse.jface 4 2 2009-06-22 10:05:22.475
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
java.lang.UnsatisfiedLinkError: Unable to load library 'libvlc': The specified module could not be found.

    at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:114)
    at com.sun.jna.NativeLibrary.getInstance(NativeLibrary.java:157)
    at com.sun.jna.Library$Handler.(Library.java:123)
    at com.sun.jna.Native.loadLibrary(Native.java:260)
    at com.sun.jna.Native.loadLibrary(Native.java:246)
    at org.videolan.jvlc.internal.LibVlc.(LibVlc.java:41)
    at org.videolan.jvlc.JVLC.(JVLC.java:45)
    at com.bah.gs.arts.jekyll.plugins.videolog.VideoLogDisplay.displayStream(VideoLogDisplay.java:32)
    at com.bah.gs.arts.jekyll.core.extensionpoints.DisplayStreamFactory.getDisplayStreams(DisplayStreamFactory.java:57)
    at com.bah.gs.arts.jekyll.core.views.medialist.MediaListView$1.doubleClick(MediaListView.java:91)
    at org.eclipse.jface.viewers.StructuredViewer$1.run(StructuredViewer.java:799)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
    at org.eclipse.core.runtime.Platform.run(Platform.java:880)
    at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
    at org.eclipse.jface.viewers.StructuredViewer.fireDoubleClick(StructuredViewer.java:797)
    at org.eclipse.jface.viewers.AbstractTreeViewer.handleDoubleSelect(AbstractTreeViewer.java:1419)
    at org.eclipse.jface.viewers.StructuredViewer$4.widgetDefaultSelected(StructuredViewer.java:1173)
    at org.eclipse.jface.util.OpenStrategy.fireDefaultSelectionEvent(OpenStrategy.java:237)
    at org.eclipse.jface.util.OpenStrategy.access$0(OpenStrategy.java:234)
    at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:295)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3823)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3422)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2384)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2348)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2200)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:495)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:490)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at com.bah.gs.arts.jekyll.core.Application.start(Application.java:20)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:193)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:386)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:549)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1212)

如何通知插件B（或RCP-APP）.dll在插件A的特定文件夹中？

似乎api希望通过它的环境PATH变量找到.dll。

我如何实质上传达“插件A /文件夹名称”？

感谢您的协助。

Answer 1

要访问plugin-a /文件夹中的.DLL文件，您需要访问插件A的Bundle实例。一种方法是为插件A实现Activator它至少扩展了Plugin类（“PluginA”）。

调用PluginA.getDefault().getBundle().getEntry("folder/some.dll")将返回.DLL文件的URL。

恕我直言，最好将所有直接访问.DLL文件的代码放入插件A.这样就不需要将插件的内部文件结构暴露给用户了。

Answer 2

您可能希望查看插件片段;这提供了一种机制，使公众面对Java API与（平台特定的）dll / so文件区别开来。

SWT的包装将是开始研究这类问题的好地方。

Answer 3

你可以构建一个“二进制”插件，将dll放在子文件夹bin中，然后在清单中确保 *您添加激活器+单件属性。 *您在“构建”，“运行时构建”部分

中检查bin /

在包含二进制文件插件的功能中，请务必选中“安装后解压缩插件存档”

在二进制文件插件的激活器中，添加如下内容：

public enum Tool {reach, ctl, ltl};
private static URI toolUri [] = new URI [3];

public static URI getProgramURI(Tool tool) throws IOException {
    if (toolUri[tool.ordinal()] == null) {
        String relativePath = "bin/its-"+ tool.toString() ;
        URL toolff = getDefault().getBundle().getResource(relativePath);
        if (toolff == null) {
            log.severe("unable to find an executable [" + tool + "] in path " + relativePath);
            Enumeration<URL> e = getDefault().getBundle().findEntries("bin/", "*", true);
            log.fine("Lising URL available in bin/");
            while (e.hasMoreElements()) {
                log.finer(e.nextElement().toString());
            }
            throw new IOException("unable to find the tool binary");
        }
        URL tmpURL = FileLocator.toFileURL(toolff);

        // use of the multi-argument constructor for URI in order to escape appropriately illegal characters
        URI uri;
        try {
            uri = new URI(tmpURL.getProtocol(), tmpURL.getPath(), null);
        } catch (URISyntaxException e) {
            throw new IOException("Could not create a URI to access the binary tool :", e);
        }
        toolUri[tool.ordinal()] = uri;
        log.fine("Location of the binary : " + toolUri);

        File crocExec = new File(uri);
        if (!crocExec.setExecutable(true)) {
            log.severe("unable to make the command-line tool executable [" + toolUri + "]");
            throw new IOException("unable to make the command-line tool executable");
        }       

    }
    return toolUri[tool.ordinal()];
}

我从我的一些代码中复制粘贴，很抱歉它与您的DLL示例不完全匹配，我从限制列表中获取可执行路径（请参阅枚举工具）。最后一步（在文件上设置+ x标志）在您的情况下可能没用。另一方面，你可以免费得到一些异常处理代码和缓存:)而且它的测试非常彻底。

它完成你要做的工作，将url传递给二进制文件到下游插件。

Eclipse RCP / Plug-in Question

3 个答案: