WebappClassLoader无法加载资源

我有以下代码尝试读取DICOM图像：WebappClassLoader无法加载资源

public BufferedImage readDicomFile(File dicomFile) { 

    ImageReader reader = (ImageReader) ImageIO.getImageReadersByFormatName("DICOM").next(); 
    BufferedImage tempImage = null; 
    try { 
     if (!dicomFile.exists()) {   
      return null; 
     } 
     ImageIO.scanForPlugins(); 
     tempImage = ImageIO.read(dicomFile);    
     DicomObject obj = new DicomInputStream(dicomFile).readDicomObject(); 
     String overlayData = obj.getString(1610625024); 
     if ((overlayData != null) && (overlayData.length() > 0)) { 
      tempImage = combineImages(tempImage, 
        OverlayUtils.extractOverlay(obj, 1610625024, reader, 
          "FFFFFF")); 
     } 
    } catch (IOException ex) { 
     ex.printStackTrace(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    return tempImage; 
}

然而，这就是我得到：

SEVERE: java.lang.IllegalStateException: WEB9031: WebappClassLoader unable to load resource [org.dcm4che.data.DcmParserFactory], because it has not yet been started, or was already stopped 
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1401) 
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1359) 
at org.dcm4cheri.imageio.plugins.DcmImageReaderSpi.canDecodeInput(DcmImageReaderSpi.java:113) 
at javax.imageio.ImageIO$CanDecodeInputFilter.filter(ImageIO.java:567) 
at javax.imageio.spi.FilterIterator.advance(ServiceRegistry.java:810) 
at javax.imageio.spi.FilterIterator.<init>(ServiceRegistry.java:804) 
at javax.imageio.spi.ServiceRegistry.getServiceProviders(ServiceRegistry.java:508) 
at javax.imageio.ImageIO.getImageReaders(ImageIO.java:646) 
at javax.imageio.ImageIO.read(ImageIO.java:1438) 
at javax.imageio.ImageIO.read(ImageIO.java:1308) 
at edu.kfshrc.dm.services.DicomViewerService.readDicomFile(DicomViewerService.java:565) 
at edu.kfshrc.dm.services.DicomViewerService.extractImageFromDicom(DicomViewerService.java:414) 
at edu.kfshrc.dm.servlet.DicomViewerServlet.doGet(DicomViewerServlet.java:131) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:668) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:770) 
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) 
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655) 
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161) 
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231) 
at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317) 
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195) 
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860) 
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757) 
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056) 
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229) 
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137) 
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104) 
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90) 
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79) 
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54) 
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59) 
at com.sun.grizzly.ContextTask.run(ContextTask.java:71) 
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532) 
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513) 
at java.lang.Thread.run(Thread.java:722) 

SEVERE:  at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1401) 
SEVERE:  at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1359) 
SEVERE:  at org.dcm4cheri.imageio.plugins.DcmImageReaderSpi.canDecodeInput(DcmImageReaderSpi.java:113) 
SEVERE:  at javax.imageio.ImageIO$CanDecodeInputFilter.filter(ImageIO.java:567) 
SEVERE:  at javax.imageio.spi.FilterIterator.advance(ServiceRegistry.java:810) 
SEVERE:  at javax.imageio.spi.FilterIterator.<init>(ServiceRegistry.java:804) 
SEVERE:  at javax.imageio.spi.ServiceRegistry.getServiceProviders(ServiceRegistry.java:508) 
SEVERE:  at javax.imageio.ImageIO.getImageReaders(ImageIO.java:646) 
SEVERE:  at javax.imageio.ImageIO.read(ImageIO.java:1438) 
SEVERE:  at javax.imageio.ImageIO.read(ImageIO.java:1308) 
SEVERE:  at edu.kfshrc.dm.services.DicomViewerService.readDicomFile(DicomViewerService.java:565) 
SEVERE:  at edu.kfshrc.dm.services.DicomViewerService.extractImageFromDicom(DicomViewerService.java:414) 
SEVERE:  at edu.kfshrc.dm.servlet.DicomViewerServlet.doGet(DicomViewerServlet.java:131) 
SEVERE:  at javax.servlet.http.HttpServlet.service(HttpServlet.java:668) 
SEVERE:  at javax.servlet.http.HttpServlet.service(HttpServlet.java:770) 
SEVERE:  at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550) 
SEVERE:  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281) 
SEVERE:  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) 
SEVERE:  at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655) 
SEVERE:  at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595) 
SEVERE:  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161) 
SEVERE:  at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331) 
SEVERE:  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231) 
SEVERE:  at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317) 
SEVERE:  at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195) 
SEVERE:  at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860) 
SEVERE:  at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757) 
SEVERE:  at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056) 
SEVERE:  at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229) 
SEVERE:  at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137) 
SEVERE:  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104) 
SEVERE:  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90) 
SEVERE:  at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79) 
SEVERE:  at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54) 
SEVERE:  at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59) 
SEVERE:  at com.sun.grizzly.ContextTask.run(ContextTask.java:71) 
SEVERE:  at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532) 
SEVERE:  at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513) 
SEVERE:  at java.lang.Thread.run(Thread.java:722)

我传递一个文件指向特定路径的对象：“c：\ temp2 \ testing.dcm”。当它试图读取Dicom文件时，会出现上述错误。

你能帮忙吗？

来源

2016-11-09 WAEL ELMASSARANI

我用“ImageIO.scanForPlugins（）”和它的工作。但是，它始终无法正常工作。这是零星的。此外，使用“ImageIO.read（dicomFile）”读取图像也是零星的。有时，阅读成功，有时它会出现“NullPointerException”或“无法获取格式”。有时，它不会给出错误，但会错误地读取，导致无法写入的图像。 –

萨拉姆瓦埃勒，

的根本原因的问题是Servlet容器（Tomcat的，..）不能处理登记/去登记本机库自动

这意味着当dcm4che负载的ImageIO DICOM插件，它如果你想从另一个webapp（Servlet）使用它，你必须再次扫描该插件以执行dcm4che DICOM读写器代码。

我建议自行注销原生的ImageIO插件每个excution之后，以防止潜在的内存泄漏在未来

 try{ 
ImageIO.scanForPlugins() 
    //Dicom code 
     } 
    catch { 
    //exceptions 
    } 
    finally { 
       try { 
        // De-register any locally registered IIO plugins. Relies on 
        // each web app having its own context class loader. 
        final IIORegistry registry = IIORegistry.getDefaultInstance(); 
        final LocalFilter localFilter = new LocalFilter(Thread.currentThread().getContextClassLoader()); 

        // scanForPlugins uses context class loader 
        Iterator<Class<?>> categories = registry.getCategories(); 

        while (categories.hasNext()) { 
         Class<?> category = categories.next(); 
         Iterator<?> providers = registry.getServiceProviders(category, localFilter, false); 

         // Copy the providers, as de-registering while iterating 
         // over providers will lead to 
         // ConcurrentModificationExceptions. 
         List<Object> providersCopy = new ArrayList<Object>(); 
         while (providers.hasNext()) { 
          providersCopy.add(providers.next()); 
         } 

         for (Object provider : providersCopy) { 
          registry.deregisterServiceProvider(provider); 
          log.debug(String.format("Unregistered locally installed provider class: %s",provider.getClass())); 
         } 
        } 
       } catch (Exception ex) { 
        _logger.error("Exception occured while de-registering locally registered IIO plugins", ex); 
       }

来源

2016-11-23 09:59:46

对不起，延迟回复。非常感谢。它实际上工作。在那之后，我正面临一件小事。当我对代码进行一些更改并编译时，它在转换为JPEG图像时会出现错误。这是错误：SEVERE：java.lang.IllegalStateException：无法获得格式当我重新启动我的应用程序服务器，这是glassfish，然后它工作正常，此错误消失。你是否知道为什么会发生这种情况，以及如何消除重新启动服务器的需要？ –

Salam Wael 这个云发生的原因有很多，它很难知道没有看到代码，也请记住，JPEG插件的JPEG阅读器和作家使用nativeLib作为压缩算法的实现我推荐到 -have ImageIo jar文件+在全球玻璃鱼库目录本地的dll不在Web应用程序的WEB-INF \ lib中 -cleanup使用插件每个请求后型扫描的插件让读者和服务员每次这可以帮助你在一般前，不代码调查 –

对于迟到的回复Ahmed不好意思。当我将所有位于WEB-INF \ lib文件夹下的jar文件移动到C：\ opt \ glassfish3 \ glassfish \ lib文件夹时，它工作正常。我试图做很多次更改，并且无需重新启动服务器即可正常工作。 –

WebappClassLoader无法加载资源

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