Java通过图片url地址获取图片base64位字符串

柔情只为你懂 2023-10-09 12:32 35阅读 0赞

/**
         * <getImgFromUrl>
         *
         * @param imgUrl imgUrl
         * @return pic base64
         * @throws
         */
        private String getImgFromUrl(String imgUrl)
            throws Exception
        {
            URL url = null;
            InputStream is = null;
            ByteArrayOutputStream outStream = null;
            HttpURLConnection httpUrl = null;
    
            try
            {
                url = new URL(imgUrl);
                httpUrl = (HttpURLConnection)url.openConnection();
                httpUrl.connect();
                httpUrl.getInputStream();
                is = httpUrl.getInputStream();
                outStream = new ByteArrayOutputStream();
                //创建一个Buffer字符串
                byte[] buffer = new byte[1024];
                //每次读取的字符串长度，如果为-1，代表全部读取完毕
                int len = 0;
                //使用一个输入流从buffer里把数据读取出来
                while ((len = is.read(buffer)) != -1)
                {
                    //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
                    outStream.write(buffer, 0, len);
                }
    
                // 对字节数组Base64编码
                return Base64Util.encode(outStream.toByteArray());
    
            }
            catch (Exception e)
            {
                logger.error("get picture catch exception. cause: ", e);
                throw new Exception(e);
            }
            finally
            {
                if (is != null)
                {
                    try
                    {
                        is.close();
                    }
                    catch (IOException e)
                    {
                        logger.error("close InputStream catch exception. cause: ", e);
                    }
                }
    
                if (outStream != null)
                {
                    try
                    {
                        outStream.close();
                    }
                    catch (IOException e)
                    {
                        logger.error("close OutputStream catch exception. cause: ", e);
                    }
                }
                if (httpUrl != null)
                {
                    httpUrl.disconnect();
                }
            }
    
        }

@Component
    public class Base64Util
    {
        private static final Logger LOGGER = LoggerFactory.getLogger(Base64Util.class);
    
        /**
         * 字符串转图片
         *
         * @param base64Str
         * @return
         */
        public static byte[] decode(String base64Str)
            throws IOException
        {
            BASE64Decoder decoder = new BASE64Decoder();
            return decoder.decodeBuffer(replaceEnter(base64Str));
        }
    
        /**
         * 图片转字符串
         *
         * @param image
         * @return
         */
        public static String encode(byte[] image)
        {
            BASE64Encoder decoder = new BASE64Encoder();
            return replaceEnter(decoder.encode(image));
        }
    
        public static String encode(String uri)
        {
            BASE64Encoder encoder = new BASE64Encoder();
            return replaceEnter(encoder.encode(uri.getBytes()));
        }
    
        /**
         * @return
         * @path 图片路径
         */
        public static byte[] imageTobyte(String path)
        {
            byte[] data = null;
            FileImageInputStream input = null;
            try
            {
                input = new FileImageInputStream(new File(path));
                ByteArrayOutputStream output = new ByteArrayOutputStream();
                byte[] buf = new byte[1024];
                int numBytesRead = 0;
                while ((numBytesRead = input.read(buf)) != -1)
                {
                    output.write(buf, 0, numBytesRead);
                }
                data = output.toByteArray();
                output.close();
                input.close();
    
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
    
            return data;
        }
    
        public static String replaceEnter(String str)
        {
            String reg = "[\n-\r]";
            Pattern p = Pattern.compile(reg);
            Matcher m = p.matcher(str);
            return m.replaceAll("");
        }
    }