Question

我正在搜索一周，但找不到适合我问题的解决方案。所以我在这里问专家。

我正在尝试使用FileUpload实现一个页面，以便在上传到相同页面后上传并显示图像。

我的问题是，如果我将ManagedBean设置为@RequestScope，则不会触发handleFileUpload函数。如果我将其设置为@ViewScope，则会触发该函数，但错误“流动态资源中出错”。显示。

这是我的档案：

的web.xml

<filter>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
<init-param>
    <param-name>thresholdSize</param-name>
    <param-value>2097152</param-value>
</init-param>
<init-param>
    <param-name>uploadDirectory</param-name>
    <param-value>E:/uploadedImages</param-value>
</init-param>

PrimeFaces FileUpload过滤器面对Servlet

豆

@ManagedBean
@RequestScoped
public class ImageManager implements Serializable {

private final static int MAX_UPLOADED_FILES = 5;
private final static String UPLOADED_FILES_PATH = "E:/uploadedImages";

private final Map<UUID, UploadedFile> uploadedFiles = new HashMap<>();

public List<String> getListImages() {
    final List<String> result = new ArrayList<>();

    for (final UUID uuid : uploadedFiles.keySet())
        result.add(uuid.toString());

    return result;
}

public StreamedContent getImage() {
    final ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
    final String imageId = (String) externalContext.getRequestMap().get("imageId");

    if (imageId != null) {
        final UUID imageIndex = UUID.fromString(imageId);
        return new DefaultStreamedContent(new ByteArrayInputStream(uploadedFiles.get(imageIndex).getContents()), "image/jpg");
    }

    return null;
}

public void handleFileUpload(FileUploadEvent event) {
    if (uploadedFiles.size() < MAX_UPLOADED_FILES) {
        final UploadedFile uploadedFile = event.getFile();
        if (uploadedFile != null) {
            uploadedFiles.put(UUID.randomUUID(), uploadedFile);
        }
    }
}

}

XHTML

              <p:fileUpload fileUploadListener="#{imageManager.handleFileUpload}"  
                        mode="advanced"
                        multiple="true"  
                        sizeLimit="2097152"
                        allowTypes="/(\.|\/)(gif|jpe?g|png)$/"
                        uploadLabel="Hochladen"
                        auto="false"
                        cancelLabel="Abbrechen"
                        invalidFileMessage="Die ausgewählte Datei ist kein zugelassene Bilddatei"
                        invalidSizeMessage="Die maximale Bildgröße ist 2MB"
                        label="Datei Auswählen"
                        update="imageList"
                        />



    <ui:repeat value="#{imageManager.listImages}" var="imageId" id="imageList">
        <h:outputText value="#{imageId}" />
        <p:graphicImage value="#{imageManager.image}">
            <f:param id="imageId" name="imageId" value="#{imageId}" />
        </p:graphicImage>
    </ui:repeat>

Answer 1

@Daniel，谢谢我。在我发布问题之前，我已经搜索了很多天。但我自己解决了这个问题。

这是解决方案，以防有人遇到同样的问题：

    @Controller
    @Scope(WebApplicationContext.SCOPE_REQUEST)
    public class ImageManager implements Serializable {

        private final static int MAX_UPLOADED_FILES = 5;
        private final static String UPLOADED_FILES_PATH = "E:/uploadedImages";

        private final static Map<UUID, UploadedFile> uploadedFiles = new HashMap<>();

        private final static List<String> listImages = new ArrayList<>();
        private StreamedContent image;

        private static StreamedContent defaultImage = null;
        static {
            try {
                defaultImage = new DefaultStreamedContent(new FileInputStream(new File("E:\\uploadedImages\\t.jpg")), "image/jpg");
            }
            catch (FileNotFoundException e) {
                e.printStackTrace();
            }        
        }

        public List<String> getListImages() {
            return listImages;
        }

        public StreamedContent getImage() {
            final ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
            final String imageId = (String) externalContext.getRequestParameterMap().get("imageId");

            if (imageId != null) {
                final UUID imageIndex = UUID.fromString(imageId);
                image = new DefaultStreamedContent(new ByteArrayInputStream(uploadedFiles.get(imageIndex).getContents()), "image/jpg");

                return image;
            }

            return defaultImage;
        }

        public void handleFileUpload(FileUploadEvent event) {
            if (uploadedFiles.size() < MAX_UPLOADED_FILES) {
                final UploadedFile uploadedFile = event.getFile();
                if (uploadedFile != null) {
                    final UUID uuid = UUID.randomUUID();
                    uploadedFiles.put(uuid, uploadedFile);
                    listImages.add(uuid.toString());
                }
            }
        }

        public void setImage(StreamedContent image) {
            this.image = image;
        }

    }

Primefaces多个FileUpload不显示文件也不触发handleFileUpload

1 个答案: