当我使用o:graphicImage时，图像不显示 [英] When I use o:graphicImage, the image is not displayed

问题描述

我无法显示数据库中的图像，它们存储为 bytea ，我正在这样映射它们:

I can´t display images from my database, they are stored as bytea and I am mapping them like this:

@Entity
@Table(name = "photograph", schema = "public")
public class Photograph{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "photograph_id", unique = true, nullable = false)
    private Long id;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "diagnostic_id", nullable = false, insertable = false, updatable = false)
    private Diagnostic diagnostic;

    @Column(name = "photo", nullable = false)
    private byte[] photo;

    @Column(name = "photograph_description", nullable = false, length = 100)
    private String photographDescription;

    @Column(name = "photograph_content_type")
    private String photographContentType;

//Getters and Setters...
}

我可以毫无问题地将所有图像存储在数据库中.问题是当我想在 p:dataTable 中显示它们时，如下所示:

I can store all the images in the database with no problem. The problem is when I want to show them in a p:dataTable like this:

<p:dataTable id="dataTableLoadedPhotos"
                value="#{imageController.photographListUpdate}" var="image">
                <p:column headerText="Fotografías cargadas" width="110">
                    <o:graphicImage value="#{imageStreamer.getById(image.photographId)}"
                        alt="#{msgs['label.diagnostic.photograph.notFound']}" />
                </p:column>
            </p:dataTable>

我正在使用基于 The BalusC代码的流光 :ImageServlet ，我尝试使用 o:graphicImage 失败，结果是mi代码中缺少:

I am using a streamer based on The BalusC Code: ImageServlet and I tried to use o:graphicImage with no success, something is missing in mi code:

@ManagedBean
@ApplicationScoped
public class ImageStreamer {

@EJB
private PhotographService photographService;

public byte[] getById(Long id) {
    try {
        return photographService.getContent(id);
    } catch (ServiceException e) {
        FacesMessage mensaje = new FacesMessage(
                FacesMessage.SEVERITY_ERROR,
                "Error al buscar la fotografía ", e.getMessage());
        FacesContext.getCurrentInstance().addMessage(null, mensaje);
    }
    return null;
}
}

我还有一个带有@RequestScoped的托管bean:

I also have a managed bean with @RequestScoped:

@ManagedBean
@RequestScoped
public class ImageController {

@EJB
private PhotographService photographService;

@ManagedProperty(value = "#{diagnosticDataManager}")
private DiagnosticDataManager diagnosticDataManager;

private List<Photograph> photographListUpdate = new ArrayList<Photograph>();
private Photograph selectedPhoto;

/**
 * 
 */
public ImageController() {
    diagnosticDataManager = new DiagnosticDataManager();
}

@PostConstruct
public void init() {
    if (diagnosticDataManager.getDiagnostic().getDiagnosticId() != null)
        photographListUpdate = photographService
                .findPhotosByDiagnostic(diagnosticDataManager
                        .getDiagnostic());

    for (Photograph photograph : photographListUpdate) {
        byte[] imageContent = org.apache.commons.codec.binary.Base64
                .decodeBase64(photograph.getPhoto());
        ExternalContext ec = FacesContext.getCurrentInstance()
                .getExternalContext();
        ec.getSessionMap()
                .put(photograph.getId().toString(),
                        imageContent);
    }
}
// Getters and setters....
}

我在p:dataTable中仅看到两行对应于没有图像的预加载图像，只显示了o:graphicImage的"alt"属性消息

I only see two rows in p:dataTable corresponding to the images preloaded with no image, just the message of "alt" attribute of the o:graphicImage is shown

使用萤火虫，我只会在每一行上看到它:

Using firebug I only see this on each row:

<img alt="Imagen no encontrada" src="/patientdiagnostics/javax.faces.resource/ImageStreamer_getById.xhtml?ln=omnifaces.graphic&v=0&p=7">

我还尝试了类似的操作< p:graphicImage>中的图像在< ui:repeat>

推荐答案

我可以毫无问题地将所有图像存储在数据库中.

因此，这实际上是不正确的.这些图像似乎是空的或仅填充了零.

This was thus actually not true. Those images appear to be empty or filled with only zeroes.

如何从<p:fileUpload>抓取上传的文件内容，请转到以下答案:

How to grab the uploaded file content from a <p:fileUpload>, head to the following answers:

• 如何使用PrimeFaces p:fileUpload?永远不会调用侦听器方法或UploadedFile为空
• 如何从p:fileUpload在MySQL中是BLOB吗?

• How to use PrimeFaces p:fileUpload? Listener method is never invoked or UploadedFile is null
• How to insert uploaded image from p:fileUpload as BLOB in MySQL?

无关与具体问题无关，因为您要添加到流媒体的catch块中的面对消息不会出现在任何地方，因为图像请求不代表JSF页面.您最好只记录/发送邮件.

Unrelated to the concrete problem, that faces message which you're trying to add in the catch block of the streamer won't appear anywhere as the image request doesn't represent a JSF page. You'd better just log/mail it.

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