Java中PNG图片透明背景变黑

package com.example.demo;

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

public class Demo {

    public static void main(String[] args) throws Exception {
        String srcImg = "D:\\1.png";//输入图片文件
        String desImg2 = "D:\\2.png";//输出图片文件--背景由透明变成黑色
        String desImg3 = "D:\\3.png";//输出图片文件--背景透明不变
        transparent(srcImg, desImg2, false);
        transparent(srcImg, desImg3, true);
    }
    
    private static void transparent(String srcImg, String desImg, boolean transparent) throws Exception {
        Image img = ImageIO.read(new File(srcImg));
        BufferedImage bufImg = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_RGB);
        Graphics2D g = bufImg.createGraphics();
        //是否透明
        if(transparent) {       
            bufImg = g.getDeviceConfiguration().createCompatibleImage(img.getWidth(null), img.getHeight(null), Transparency.TRANSLUCENT);
            g = bufImg.createGraphics();
        }
        g.drawImage(img, 0, 0, null);
        ImageIO.write(bufImg, "png", new File(desImg));
    }
    
}

输出：