【Java】base64与字符串和图片的互转

base64转string字符串¹

        String base64encodedString = "5oiR5piv54i354i3";
        // 解码
        byte[] base64decodedBytes = Base64.getDecoder().decode(base64encodedString);
        try {
            System.out.println("原始字符串: " + new String(base64decodedBytes, "utf-8"));
        }
        catch (UnsupportedEncodingException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

结果：

我是爷爷

string字符串转base64

// 字符串转base64
System.out.println(Base64.getEncoder().encodeToString("我是爷爷".getBytes("utf-8")));

结果：

5oiR5piv54i354i3

图片与base64的互转

    /**
     * 将图片转换成Base64编码
     * @param imgFile 待处理图片地址
     * @return
     */
    public String getImgBase(String imgFile) {

        // 将图片文件转化为二进制流
        InputStream in = null;
        byte[] data = null;
        // 读取图片字节数组
        try {
            in = new FileInputStream(imgFile);
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 图片头
        //String imghead = "data:image/jpeg;base64,";
        return Base64.getEncoder().encodeToString(data);
    }
    
    /**
     * base64转图片
    * @param base64Code base64码
    */
    public void convertBase64ToImage(String base64Code){
        BufferedImage image = null;
        byte[] imageByte = null;
        try {
            imageByte = DatatypeConverter.parseBase64Binary(base64Code);
            ByteArrayInputStream bis = new ByteArrayInputStream(imageByte);
            image = ImageIO.read(new ByteArrayInputStream(imageByte));
            bis.close();
            File outputfile = new File("D:/test.jpg");
            ImageIO.write(image, "png", outputfile);
        } 
        catch (IOException e) {
            e.printStackTrace();
        }
    }

---

1. https://www.runoob.com/java/java8-base64.html ↩︎