图片上传图片预览

Question

大家好，希望你能帮助我在选择图像后显示预览图像或缩略图，而不是按下上传按钮。希望你们能帮助我！谢谢..

Profile Image Upload

Answer 1

这是我上传处理程序的代码，这里的temp_storage_path是本地应用程序临时路径

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import com.wcs.wcslib.vaadin.widget.multifileupload.ui.UploadFinishedHandler;

public class ImageUploadFinishedHandler implements UploadFinishedHandler {

    VerticalLayout imageLayout;

    public ImageUploadFinishedHandler(VerticalLayout imageLayout) {
        this.imageLayout = imageLayout;
    }

    @Override
    public void handleFile(InputStream stream, String fileName, String arg2, long arg3) {
        File file = null;
        try {
            file = new File("temp_storage_path"+fileName);
            OutputStream outputStream = new FileOutputStream(file);
            int read = 0;
            byte[] bytes = new byte[1024];
            while ((read = stream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
            outputStream.close();
        } catch (FileNotFoundException e) {
            return;
        } catch (IOException e) {
            return;
        }
        this.imageLayout.removeAllComponents();

        Image previewImage = new Image();
        this.imageLayout.addComponent(previewImage);
        previewImage.setWidth("100px");
        previewImage.setHeight("100px");
        previewImage.setSource(new FileResource(file));
    }

}