java - 页面上未找到 Wicket 图像组件

Question

尝试显示项目列表时遇到以下问题。对于每个项目，我必须显示通过 Wicket WebResource 动态加载的图像。这些项目会在用户滚动时使用 Ajax 滚动逐步加载(一次加载 50 个)。

[ERROR] 2011-04-19 09:58:18,000 btpool0-1 org.apache.wicket.RequestCycle.logRuntimeException (host=, request=, site=): org.apache.wicket.WicketRuntimeException: component documentList:scroller:batchElem:666:content:item:3:batchItemContent:linkToPreview:imageThumbnail not found on page com.webapp.document.pages.DocumentListPage[id = 1] listener interface = [RequestListenerInterface name=IResourceListener, method=public abstract void org.apache.wicket.IResourceListener.onResourceRequested()]

org.apache.wicket.protocol.http.request.InvalidUrlException: org.apache.wicket.WicketRuntimeException: component documentList:scroller:batchElem:666:content:item:3:batchItemContent:linkToPreview:imageThumbnail not found on page com.webapp.document.pages.DocumentListPage[id = 1] listener interface = [RequestListenerInterface name=IResourceListener, method=public abstract void org.apache.wicket.IResourceListener.onResourceRequested()] at org.apache.wicket.protocol.http.WebRequestCycleProcessor.resolve(WebRequestCycleProcessor.java:262) at org.apache.wicket.RequestCycle.step(RequestCycle.java:1310) at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1428) at org.apache.wicket.RequestCycle.request(RequestCycle.java:545) at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:479) at org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.CGLIB$doGet$6() at org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816$$FastClassByGuice$$6d42bf5d.invoke() at com.google.inject.internal.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) at com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:64) at com.freiheit.monitoring.PerformanceMonitoringMethodInterceptor.invoke(PerformanceMonitoringMethodInterceptor.java:115) at com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:64) at com.google.inject.internal.InterceptorStackCallback.intercept(InterceptorStackCallback.java:44) at org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.doGet() at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:312) at org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.CGLIB$doFilter$4()

如何解决这个问题？

以下是负责添加图像的代码部分:

previewLink.add(createThumbnailSmall("imageThumbnail", documentModel));

在

createThumbnailSmall(final String id, final IModel<BaseDocument> documentModel) {
    // thumbnailResource is an object that contains the path of the image

    if (thumbnailResource != null) {
        final WebResource resource = getWebResource(thumbnailResource);
        final Image image = new Image(id, resource);
        return image;
    }
    return new InvisibleContainer(id);
}

WebResource getWebResource(final DocumentResource documentResource) {
    return new WebResource() {

        private static final long serialVersionUID = 1L;

        @Override
        public IResourceStream getResourceStream() {
            return new BaseStreamResource(documentResource);
        }
    };
}

其中 BaseStreamResource 如下:

public class BaseStreamResource extends AbstractResourceStream {
    private InputStream      _fileInputStream = null;
    private DocumentResource _resource        = null;

    public BaseStreamResource(final DocumentResource documentResource) {
        _resource = documentResource;
    }

    @Override
    public InputStream getInputStream() throws ResourceStreamNotFoundException {
        if (_fileInputStream == null) {
            try {
                if (_resource == null) {
                    throw new ResourceStreamNotFoundException("Resource was null");
                }
                _fileInputStream = _resource.getFileInputStream();
            } catch (final ResourceNotAvailableException ex) {
                throw new ResourceStreamNotFoundException(ex);
            }
        }
        return _fileInputStream;
    }

在 HTML 中:

<a wicket:id="linkToPreview" href="#">
<img wicket:id="imageThumbnail" alt="Attachment"></img></a>

Answer 1

添加的代码并没有真正为我添加任何线索，但也许我可以帮助缩小范围。

堆栈跟踪包含对 com.webapp.document.pages.DocumentListPage 的引用，它可能调用您发布的一些代码。该错误表明 url 错误，因此调试该类、添加调试打印以及查看包含 url 的任何字段的值可能是值得的。

它甚至可能有助于修改 DocumentListPage 中的代码(可能暂时用于调试)以捕获 org.apache.wicket.protocol.http.request.InvalidUrlException 并添加当捕获异常时，调试会专门打印。

这并不是真正的答案，但对于评论来说太大了，也许它会帮助您更接近答案。