当我使用 o:graphicImage 时，图像不显示

Question

我无法显示我的数据库中的图像，它们存储为 bytea，我正在像这样映射它们：

@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。问题是当我想像这样在 p:dataTable 中显示它们时：

<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 Code: ImageServlet 的流媒体，我尝试使用o:graphicImage 没有成功，mi 代码中缺少某些内容：

@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：

@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....
}

我只看到 p:dataTable 中的两行对应于没有图像预加载的图像，只显示了 o:graphicImage 的“alt”属性的消息

使用萤火虫我只在每一行看到这个：

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

我也试过类似Display database blob images in <p:graphicImage> inside <ui:repeat>的东西

Answer 1

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只填充了零。

如何从<p:fileUpload>获取上传的文件内容，请前往以下答案：

• 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?

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与具体问题无关，由于图像请求不代表 JSF 页面，因此您尝试添加到流媒体的 catch 块中的消息不会出现在任何地方。你最好只记录/邮寄。