图片显示

    /**
     * 图片显示
     *
     * @throws IOException
     */
    public static void photoShow() throws IOException {
        File file = new File("D:\\Java\\IdeaProjects\\acs\\RE4Ik0b_1920x1080.jpg");
        BufferedImage bufferedImage = ImageIO.read(file);
        ImageIcon imageIcon = new ImageIcon(bufferedImage);
        JFrame jFrame = new JFrame();
        jFrame.setLayout(new FlowLayout());
        jFrame.setSize(500, 500);
        JLabel jLabel = new JLabel();
        jLabel.setIcon(imageIcon);
        jFrame.add(jLabel);
        jFrame.setVisible(true);
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

图片转化成base64字符串

    /**
     * 图片转化成base64字符串
     *
     * @return
     */
    public static String GetImageStr() {//将图片文件转化为字节数组字符串，并对其进行Base64编码处理
        String imgFile = "D:\\Java\\IdeaProjects\\acs\\RE4Ik0b_1920x1080.jpg";//待处理的图片
        InputStream in = null;
        byte[] data = null;
        //读取图片字节数组
        try {
            in = Files.newInputStream(Paths.get(imgFile));
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data);//返回Base64编码过的字节数组字符串
    }

base64字符串转化成图片

    /**
     * base64字符串转化成图片
     *
     * @param imgStr base64字符串
     * @return
     */
    public static boolean GenerateImage(String imgStr) { //对字节数组字符串进行Base64解码并生成图片
        if (imgStr == null) //图像数据为空
            return false;
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            //Base64解码
            byte[] b = decoder.decodeBuffer(imgStr);
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {//调整异常数据
                    b[i] += 256;
                }
            }
            //生成jpeg图片
            String imgFilePath = "D:\\Java\\IdeaProjects\\acs\\RE4Ik0b_1920x10802.jpg";//新生成的图片
            OutputStream out = Files.newOutputStream(Paths.get(imgFilePath));
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }

byte[]转base64

BASE64Encoder base64Encoder = new BASE64Encoder();
String encode = base64Encoder.encode(str.getBytes());
System.out.println("转base64后：" + encode);

Base64转byte[]

BASE64Decoder base64Decoder = new BASE64Decoder();
byte[] decodeBuffer = base64Decoder.decodeBuffer(str);
System.out.println("base64转回：" + new String(decodeBuffer));