将实时图像加载到 JLabel 中不适用于某些 url

Question

我想将实时 URL 图像加载到 JLabel 中。 我已经尝试过代码，但它不适用于某些 URL。 不知道会发生什么？ 也不会发生异常。

    try {
        String imageUrl = "https://www.mouser.com/images/molex/images/501331-001a.jpg"; // not working url
       // String imageUrl = "http://in.element14.com/productimages/standard/en_GB//1458900-40.jpg"; // not working url
       // String imageUrl = "https://euroc-static.s3.amazonaws.com/verifiedcomp/pkg_files/parts_files/63661/63661.jpg"; // working url   
    
       URL url = new URL(imageUrl);     
       Image image = ImageIO.read(url);
       JFrame frame = new JFrame();
       frame.setSize(300, 300);
       JLabel label = new JLabel(new ImageIcon(image));
       frame.add(label);
       frame.setVisible(true);
    } catch (Exception e) {
      e.printStackTrace();
    }

Answer 1

编辑：此处的工作解决方案（仅从 Java 11 开始，对于旧版本，您需要找到不同的休息框架）

同样在这张图片“in.element14”中，你应该有 https 协议。

由于返回的内容长度为负数，因此无法正常工作。 HttpUrlConnection 似乎不支持这种情况。

@Andrew Thompson 不需要转换...

private void initUI() {
        JPanel images = new JPanel();
        BoxLayout boxLayout = new BoxLayout(images, BoxLayout.Y_AXIS);
        images.setLayout(boxLayout);
        images.setVisible(true);
        images.add(testLabel(
                "https://imageproxy.themaven.net//https%3A%2F%2Fwww.history.com%2F.image%2FMTY4OTA4MzI0ODc4NjkwMDAw%2Fchristmas-tree-gettyimages-1072744106.jpg"));
        images.add(testLabel("https://www.mouser.com/images/molex/images/501331-001a.jpg"));
        images.add(testLabel("https://euroc-static.s3.amazonaws.com/verifiedcomp/pkg_files/parts_files/63661/63661.jpg"));
        images.add(testLabel("https://in.element14.com/productimages/standard/en_GB/1458900-40.jpg"));
        this.add(images);
}

private JPanel testLabel(String imageUrl) {
        try {
            HttpClient client = HttpClient.newHttpClient();
            HttpRequest request = HttpRequest.newBuilder()
                                             .uri(URI.create(imageUrl)).GET()
                                             .build();
            HttpResponse<byte[]> response = client.send(request,
                                                        responseInfo -> HttpResponse.BodySubscribers.ofByteArray());
            InputStream targetStream = new ByteArrayInputStream(response.body());
            Image image = ImageIO.read(targetStream);

            JPanel panel = new JPanel();
            panel.setPreferredSize(new Dimension(200, 200));
            JLabel label = new JLabel(new ImageIcon(image));
            panel.add(label);
            panel.setVisible(true);
            return panel;

        } catch (Exception ex) {
            ex.printStackTrace();
            JPanel panel = new JPanel();
            panel.setSize(300, 300);
            JLabel label = new JLabel("Loading failed");
            panel.add(label);
            panel.setVisible(true);
            return panel;
        }
    }

Answer 2

试试这个代码。

      // String imageURL="https://imageproxy.themaven.net//https%3A%2F%2Fwww.history.com%2F.image%2FMTY4OTA4MzI0ODc4NjkwMDAw%2Fchristmas-tree-gettyimages-1072744106.jpg";
       String imageUrl = "https://www.mouser.com/images/molex/images/501331-001a.jpg"; // not working url
       // String imageUrl = "http://in.element14.com/productimages/standard/en_GB//1458900-40.jpg"; // not working url
       // String imageUrl = "https://euroc-static.s3.amazonaws.com/verifiedcomp/pkg_files/parts_files/63661/63661.jpg"; // working url   
    
        Image image = null;
        try {
            URL url = new URL(imageURL);
            image = ImageIO.read(url);
        } 
        catch (IOException e) {
        }
        JFrame frame = new JFrame();
        JLabel label = new JLabel(new ImageIcon(image));
        frame.getContentPane().add(label, BorderLayout.CENTER);
        JPanel Panel = new JPanel(new BorderLayout());
        Panel.add(label);
        frame.add(Panel);
        frame.setSize(300, 400);
        frame.setVisible(true);

这应该可以完美运行

Answer 3

你确定

// String imageUrl = "http://in.element14.com/productimages/standard/en_GB//1458900-40.jpg";

此网址无效。我怀疑这是一个 SSL 问题。这意味着您无法访问图片的 startWith 'https://' URL。