Java 通过图片Url路径生成Base64字符串的工具类

package com.cjavapy.utils.util;
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URL;
public class ImageUtils {
    public static String getBase64ByImgUrl(String url) {
        String suffix = url.substring(url.lastIndexOf(".") + 1);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            URL urls = new URL(url);
            Image image = Toolkit.getDefaultToolkit().getImage(urls);
            BufferedImage biOut = toBufferedImage(image);
            ImageIO.write(biOut, suffix, baos);
            String base64Str = Base64Convert.byteToBase64(baos.toByteArray());
            return base64Str;
        } catch (Exception e) {
            return "";
        }finally {
            try {
                baos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    public static BufferedImage toBufferedImage(Image image) {
        if (image instanceof BufferedImage) {
            return (BufferedImage) image;
        }
        // This code ensures that all the pixels in the image are loaded
        image = new ImageIcon(image).getImage();
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment
                .getLocalGraphicsEnvironment();
        try {
            int transparency = Transparency.OPAQUE;
            GraphicsDevice gs = ge.getDefaultScreenDevice();
            GraphicsConfiguration gc = gs.getDefaultConfiguration();
            bimage = gc.createCompatibleImage(image.getWidth(null),
                    image.getHeight(null), transparency);
        } catch (HeadlessException e) {
            // The system does not have a screen
        }
        if (bimage == null) {
            // Create a buffered image using the default color model
            int type = BufferedImage.TYPE_INT_RGB;
            bimage = new BufferedImage(image.getWidth(null),
                    image.getHeight(null), type);
        }
        // Copy image to buffered image
        Graphics g = bimage.createGraphics();
        // Paint the image onto the buffered image
        g.drawImage(image, 0, 0, null);
        g.dispose();
        return bimage;
    }
}