Question

嘿，我正在尝试保存一个名为“阿凡达”的对象，然后检索该对象并显示其图片“图像”。我得到这个结果：

我的头像类：

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我如何保存对象：

body {
   margin: 0;
   padding: 0;
   box-sizing: border-box;
   background-color: hsl(0, 0%, 98%);
   text-rendering: optimizeLegibility;
}

.container {
   width: 60%;
   height: 60%;
}

从头像表中检索数据：

@Entity
@Table(name="avatar")
public class Avatar implements java.io.Serializable {

    @Id
    private Integer avatarId;
    @Column(name = "image")
    private byte[] image;
//getters and setters

控制器：

session.getTransaction().begin();

        File file = new File("PicturePath");
        byte[] bFile = new byte[(int) file.length()];

        try {
            FileInputStream fileInputStream = new FileInputStream(file);
            fileInputStream.read(bFile);
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        Avatar avatar = new Avatar();
        avatar.setAvatarId(1);
        avatar.setImage(bFile);
        session.save(avatar);
        session.getTransaction().commit();

我的FXML文件：

public List<Avatar> avatarList(){
        session.getTransaction().begin();
        List<Avatar> avatar = session.createQuery("from Avatar").list();
        session.getTransaction().commit();
        return avatar;
    }

我希望实际的图片显示在表格视图中。

Answer 1

之所以看不到图像，是因为尽管您正确地向TableView提供了图像的字节，但是您没有告诉它如何呈现图像。您需要的是自定义TableCell，它将字节数组呈现为ImageView。因此，我将执行以下操作：

首先在TableColumn的fxml文件中添加一个id属性：

<TableColumn fx:id="imageColumn" text="Picture" style="-fx-backround-color:#33d9b2">
    <cellValueFactory>
        <PropertyValueFactory property="image"/>
    </cellValueFactory>
</TableColumn>

然后在Controller内引用它，并在其中添加CellFactory：

@FXML
public TableView<Avatar> produits;

@FXML
public TableColumn<Avatar, byte[]> imageColumn;

@FXML
public void initialize() {
    ...
    imageColumn.setCellFactory(param -> new TableCell<Avatar, byte[]>() {

        private ImageView imageView = new ImageView();

        @Override
        protected void updateItem(byte[] item, boolean empty) {
            super.updateItem(item, empty);
            if (item == null || empty) {
                setText(null);
                setGraphic(null);
            } else {
                imageView.setImage(getImageFromBytes(item));
                setGraphic(imageView);
            }
            this.setItem(item);
        }
    });
    ...
}

CellFactory为您的每个Avatar项目创建一个表格单元格，该单元格的updateItem()方法将字节转换为Image，然后将其渲染为{{ 1}}（如果单元格不为空）。这是将字节数组转换为JavaFX Image的一种方法：

ImageView

重要说明：：我将避免从private Image getImageFromBytes(byte[] imgBytes) { try { ByteArrayInputStream inputStream = new ByteArrayInputStream(imgBytes); BufferedImage bufferedImage = ImageIO.read(inputStream); return SwingFXUtils.toFXImage(bufferedImage, null); } catch (IOException e) { e.printStackTrace(); } return null; }内部调用getImageFromBytes()方法，尤其是对于具有大量记录的TableView。我只是为了简单起见。您可能需要预先转换图像，然后将其存储在地图或其他内容中。

编辑：更改了updateItem()方法，使其不会在每次调用时创建新的updateItem()。

我的TableView显示图片的地址，而不是实际的图片

1 个答案: