java - 在 Wicket 中验证图像尺寸

Question

我正在开发一个 webbapp，它从用户那里接收图像资源，但我想验证这些要上传的图像是否具有特定的尺寸，如 600X800 等。

我试图找到答案，但我没有选择:)。

如果有人以前这样做过，那就太好了。

感谢您的帮助将不胜感激

Answer 1

尝试

BufferedImage bi = ImageIO.read (file);
bi.getWidth();//width
bi.getHeight ();//height

Answer 2

最后我确实找到了方法：我们首先得到它要上传的文件，然后我使用一个创建的类，我在堆栈溢出时在这里找到，找到尺寸的宽度和高度，我只是玩 if's then ，这是代码，希望对某人有所帮助！

public class AddPromo extends WebPage {

/**
 * 
 */

private FileUploadField fileUpload;
private String UPLOAD_FOLDER = "..\\Promociones\\";

private static final long serialVersionUID = 1L;
@SuppressWarnings({ "rawtypes", "unchecked" })
public AddPromo(){
    add(new Label("user",ActiveUser.USER));

    //Add Feedback panel
    add(new FeedbackPanel("feedback_2"));

    //LOGOUT LINK
    Logout logoutLink = new Logout("logout");
    add(logoutLink);

    //Add backlink to SuccesPage
    add(new Link("link_atras"){
        /**
         * 
         */
        private static final long serialVersionUID = 1L;

        @Override
        public void onClick(){
            SuccesPage nueva = new SuccesPage("",1);
            setResponsePage(nueva);
        }
    });


    //Definitions for date attributes
    final Locale selectedLocale = Session.get().getLocale();

    add(new StaticImage("image_test",new Model("http://1-ps.googleusercontent.com/h/www.bizreport.com/2011/02/03/200x200xandroid-logo-200x200.jpg.pagespeed.ic.SONOBLzFc5.jpg")));


    Form<?> form = new Form<Void>("form") {
         /**
         * 
         */
        private static final long serialVersionUID = 1L;

        @Override
         protected void onSubmit() {
            JPEGDim dims = new JPEGDim();
            final FileUpload uploadedFile = fileUpload.getFileUpload();
            if (uploadedFile != null) {

                // write to a new file
                File newFile = new File(UPLOAD_FOLDER
                    + uploadedFile.getClientFileName());

                try {
                    final Dimension d = dims.getJPEGDimension(newFile);
                    if (d.getWidth()==1024 || d.getHeight()==768 ) {
                        try {
                            if (newFile.exists()) {
                                newFile.delete();
                            }
                            newFile.createNewFile();
                            uploadedFile.writeTo(newFile);
                            info("saved file: " + uploadedFile.getClientFileName());
                            info("Imagen cumple con dimensiones " + d.getHeight() + " x " + d.getWidth());

                        } catch (Exception e) {
                            throw new IllegalStateException("Error "+e.toString());
                        }
                    } else {
                        error("Archivo no valido... " +  + d.getHeight() + " x " + d.getWidth());
                    }

                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    error(e1.toString());

                }




             }

            }

        };

        // Enable multipart mode (need for uploads file)
        form.setMultiPart(true);
        // max upload size, 10k
        form.setMaxSize(Bytes.megabytes(10));
        form.add(fileUpload = new FileUploadField("fileUpload"));

    add(form);
}

class JPEGDim {

    public Dimension getJPEGDimension(File f) throws IOException {
            FileInputStream fis = new FileInputStream(f);

            // check for SOI marker
            if (fis.read() != 255 || fis.read() != 216)
                    throw new RuntimeException("SOI (Start Of Image) marker 0xff 0xd8 missing");

            Dimension d = null;

            while (fis.read() == 255) {
                    int marker = fis.read();
                    int len = fis.read() << 8 | fis.read();

                    if (marker == 192) {
                            fis.skip(1);

                            int height = fis.read() << 8 | fis.read();
                            int width = fis.read() << 8 | fis.read();

                            d = new Dimension(width, height);
                            break;
                    }

                    fis.skip(len - 2);
            }

            fis.close();

            return d;
    }

}

}