我有一个应用程序,它使用PrimeFaces Mobile来显示图像。为什么graphicImage中的图像未完全加载(PrimeFaces mobile)?
有时候,但并非总是如此,图像不能完全显示 - 只有顶部。
与图像页面的XHTML代码如下所示:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:p="http://primefaces.org/ui"
xmlns:pm="http://primefaces.org/mobile">
<f:view renderKitId="PRIMEFACES_MOBILE"/>
<h:head>
</h:head>
<f:event listener="#{main.loadFirstImage}" type="preRenderView" />
<h:body id="body">
<pm:page id="page">
<pm:header title="myapp">
</pm:header>
<pm:content id="content">
<h:form>
<p:graphicImage id="image" rendered="false" value="#{main.currentImage()}"
cache="false">
</p:graphicImage>
[...]
</h:form>
</pm:content>
<pm:footer title="m.myapp.com"></pm:footer>
</pm:page>
</h:body>
</html>
而且main
bean有以下代码:
@ManagedBean(name = "main")
@SessionScoped
public class MainView {
private byte[] currentImageData;
private byte[] productId;
private byte[] imageId;
public void loadFirstImage()
{
// This method initializes currentImageData
fetchNextImage();
}
[...]
public StreamedContent currentImage()
{
FacesContext context = FacesContext.getCurrentInstance();
if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
return new DefaultStreamedContent();
}
else {
return new DefaultStreamedContent(new ByteArrayInputStream(currentImageData));
}
}
[...]
}
我怎样才能解决这个错误?
更新1(2014年3月11日23:21 MSK):
我试过以下修正这个错误:
1)禁用缓存为Primefaces页面中的所有元素。
2)通过将maxExtensionSize
和maxTrailerSize
(server.xml
)设置为-1
来禁用响应块。
3)添加过滤器具有以下doFilter
:
@Override
public void doFilter(final ServletRequest aServletRequest,
final ServletResponse aServletResponse,
final FilterChain aFilterChain) throws IOException, ServletException {
System.out.println("aServletRequest instanceof HttpServletRequest: " +
(aServletRequest instanceof HttpServletRequest));
if (aServletRequest instanceof HttpServletRequest)
{
final HttpServletRequest request = (HttpServletRequest) aServletRequest;
final String requestURI = request.getRequestURI().toLowerCase();
if (!requestURI.endsWith("/javax.faces.resource/dynamiccontent.properties"))
{
aFilterChain.doFilter(aServletRequest, aServletResponse);
}
}
}
4)改变currentImage
方法
public StreamedContent currentImage()
{
FacesContext context = FacesContext.getCurrentInstance();
if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
// So, we're rendering the view. Return a stub StreamedContent so that it will generate right URL.
return new DefaultStreamedContent();
}
else {
String mimeType = null;
if (imageFileName.toLowerCase().endsWith(".png"))
{
mimeType = "image/png";
}
else if (imageFileName.toLowerCase().endsWith(".jpeg") || imageFileName.toLowerCase().endsWith(".jpg"))
{
mimeType = "image/jpeg";
}
// So, browser is requesting the image. Return a real StreamedContent with the image bytes.
return new DefaultStreamedContent(new ByteArrayInputStream(currentImageData), mimeType);
}
}
但它仍然无法正常工作。我在另一个Web应用程序中编写了一段代码,并使用不同的框架(Vaadin),它显示来自同一个源的图像。
我得到相同的错误(图像只显示部分)。
从这我的结论是必须发生错误
- 当图像被从一个特定的和/或
- 当图像被保存在MongoDB中检索。
代码读取图像期间从URL
如果发生错误检索图像,它发生在下面的方法:
protected Binary readImage(final String viewItemURL) {
InputStream inputStream = null;
Binary image = null;
try
{
inputStream = new URL(viewItemURL).openStream();;
byte bytes[] = new byte[inputStream.available()];
inputStream.read(bytes);
image = new Binary(bytes);
}
catch (final IOException exception)
{
LOGGER.error("", exception);
}
finally
{
IOUtils.closeQuietly(inputStream);
}
return image;
}
viewItemURL
是图像的URL。
代码如果问题是与数据库中的图像保存在MongoDB中保存图像
,它发生在下面的方法:
protected void saveProductImages(final byte[] aNewProductId, final List<String> aPictureUrls,
final IMongoPersistenceState aPersistenceState) {
final DB db = aPersistenceState.getDb();
final DBCollection productImagesColl = db.getCollection(
MyAppPersistenceAction.COLLECTION_USER_PRODUCT_IMAGES);
for (final String curPictureUrl : aPictureUrls)
{
final Binary imageData = readImage(curPictureUrl);
final Map<String,Object> map = new HashMap<String, Object>();
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_CREATOR_EMAIL, CREATOR_EMAIL);
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_PRODUCT_ID, aNewProductId);
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_DATA, imageData);
final String fileName = extractFileName(curPictureUrl);
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_FILE_NAME, fileName);
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_MIME_TYPE, getMimeType(fileName));
map.put(FIELD_COLLECTION_USER_PRODUCT_IMAGES_IS_DELETED, Boolean.FALSE);
productImagesColl.insert(WriteConcern.SAFE, createRecordObject(map));
}
}
BalusC,你是国王Java的!非常感谢(需要等待12小时才能授予奖励)。 – 2014-11-04 08:38:36