java将图片输出base64位码显示

注意需要过滤：\r \n数据

jkd1.7的

import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder;

  /**
     * 网络图片转换Base64的方法
     *
     * @param netImagePath     
     */
    public static String NetImageToBase64(String netImagePath) {
        final ByteArrayOutputStream data = new ByteArrayOutputStream();
        String strNetImageToBase64 = null;
        try {
            // 创建URL
            URL url = new URL(netImagePath);
            final byte[] by = new byte[1024];
            // 创建链接
            final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5000);
            if(conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
                return strNetImageToBase64;
                //连接失败/链接失效/图片不存在
            }

            Thread thread =new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        InputStream is = conn.getInputStream();
                        // 将内容读取内存中
                        int len = -1;
                        while ((len = is.read(by)) != -1) {
                            data.write(by, 0, len);
                        }
                        // 关闭流
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
            thread.start();
            try {
                thread.join();
            } catch (InterruptedException e) {
                 e.printStackTrace();
            }
            // 对字节数组Base64编码
            BASE64Encoder encoder = new BASE64Encoder();
            strNetImageToBase64 = encoder.encode(data.toByteArray());
            // 删除 \r\n
            strNetImageToBase64 = strNetImageToBase64.replaceAll("\n", "").replaceAll("\r", "");
            strNetImageToBase64 = "data:image/jpeg;base64," + strNetImageToBase64;

        } catch (IOException e) {
            e.printStackTrace();
        }
        return  strNetImageToBase64;
    }

1.8java.util.Base64包

/**
     * 转换为base64格式
     *
     * @param image
     * @return
     */
    public static String encode2Base64Jpg(BufferedImage image) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();// io流
        try {
            ImageIO.write(image, "jpg", baos);
        } catch (IOException e) {
            e.printStackTrace();
        }
        byte[] bytes = baos.toByteArray();// 转换成字节
        Base64.Encoder encoder = Base64.getEncoder();
        String jpgBase64 = encoder.encodeToString(bytes).trim();// 转换成base64串
        jpgBase64 = jpgBase64.replaceAll("\n", "").replaceAll("\r", "");// 删除 \r\n

        return "data:image/jpeg;base64," + jpgBase64;
    }

其他本地图片处理

/**
     * 图片转化成base64字符串
     * @param imgPath
     * @return
     */
    public static String GetImageStr(String imgPath) {// 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 = imgPath;// 待处理的图片
        InputStream in = null;
        byte[] data = null;
        String encode = null; // 返回Base64编码过的字节数组字符串
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        try {
            // 读取图片字节数组
            in = new FileInputStream(imgFile);
            data = new byte[in.available()];
            in.read(data);
            encode = encoder.encode(data);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                in.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return encode;
    }

原文地址：https://www.cnblogs.com/achengmu/p/11813995.html