在页面上找不到检票口图像组件 [英] Wicket image component not found on page
问题描述
我在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.这些项目是在用户滚动时使用 Ajax 滚动逐步加载的——一次 50 个.
I get the following problem when trying to display a list of items. For each item, I have to display an image which is dynamically loaded via a Wicket WebResource. The items are loaded step by step — 50 at a time — upon user scrolling, using an Ajax scroll.
[错误] 2011-04-19 09:58:18,000 btpool0-1 org.apache.wicket.RequestCycle.logRuntimeException (host=, request=, site=):org.apache.wicket.WicketRuntimeException: 组件 documentList:scroller:batchElem:666:content:item:3:batchItemContent:linkToPreview:imageThumbnail 在页面 com.webapp.document.pages.DocumentListPage[id = 1] 上找不到listener interface = [RequestListenerInterface name=IResourceListener, method=public abstract void org.apache.wicket.IResourceListener.onResourceRequested()]
[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: 组件 documentList:scroller:batchElem:666:content:item:3:batchItemContent:linkToPreview:imageThumbnail在 com.webapp.document.pages.DocumentListPage[id = 1] 侦听器接口 = [RequestListenerInterface name=IResourceListener, method=public abstract void org.apache.wicket.IResourceListener.onResourceRequested()] 上找不到在 org.apache.wicket.protocol.http.WebRequestCycleProcessor.resolve(WebRequestCycleProcessor.java:262)在 org.apache.wicket.RequestCycle.step(RequestCycle.java:1310)在 org.apache.wicket.RequestCycle.steps(RequestCycle.java:1428)在 org.apache.wicket.RequestCycle.request(RequestCycle.java:545)在 org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:479)在 org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.CGLIB$doGet$6()在 org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816$$FastClassByGuice$$6d42bf5d.invoke()在 com.google.inject.internal.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)在 com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:64)在 com.freiheit.monitoring.PerformanceMonitoringMethodInterceptor.invoke(PerformanceMonitoringMethodInterceptor.java:115)在 com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:64)在 com.google.inject.internal.InterceptorStackCallback.intercept(InterceptorStackCallback.java:44)在 org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.doGet()在 org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:312)在 org.apache.wicket.protocol.http.WicketFilter$$EnhancerByGuice$$51619816.CGLIB$doFilter$4()
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?
这是负责添加图像的代码部分:
Here is the part of the code responsible for adding the image:
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>
推荐答案
以下解决方案解决了问题:
- 扩展 WebResource 类
- 将扩展类作为资源添加到应用程序共享资源中
The following solution solved the problem:
- extend WebResource class
- add extended class as a resource to application shared resources
例如:
public class MyWebResource extends WebResource {
final ValueMap map = new ValueMap();
@Override
public IResourceStream getResourceStream() {
String fileName = getFileName();
File file = new File(basePath, fileName);
if (!file.exists()) {
LOG.error("File does not exist: " + file);
throw new IllegalStateException("File does not exist: " + file);
}
return new FileResourceStream(file);
}
public final void addResource() {
Application.get().getSharedResources().add(getClass().getName(), this);
}
protected String getFileName() {
return getParameters().getString("id");
}
public final String urlFor(final String fileName) {
final ResourceReference resourceReference = new ResourceReference(getClass().getName());
final String encodedValue = WicketURLEncoder.QUERY_INSTANCE.encode(fileName);
map.add("id", encodedValue);
final CharSequence result = RequestCycle.get().urlFor(resourceReference, map);
if (result == null) {
throw new IllegalStateException("The resource was not added! "
+ "In your Application class add the following line:"
+ "MyConcreteResource.INSTANCE.addResource()");
}
String absoluteUrl = RequestUtils.toAbsolutePath(result.toString());
return absoluteUrl;
}
}
在Application类的init()中，我已经将MyWebResource添加到共享资源中:
In Application class, in init(), I have added MyWebResource to shared resources:
public void init() {
...
new MyWebResource().addResource();
...
}
这篇关于在页面上找不到检票口图像组件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
