下载文件URL含中文，400 Bad Request

下载链接中有中文，造成 “400 Bad Request”。
处理方式是，把中文转码。

public class DownAdjunct {
    private String urlPath;
    private Context context;
    private String SDPath = Environment.getExternalStorageDirectory() + "/CableInspection/Download/";

    public DownAdjunct(Context context, String urlPath) {
        this.urlPath = urlPath;
        this.context = context;
    }

    public String downFile() throws IOException {
        String uriPath = "";
        // 如果相等的话表示当前的sdcard挂载在手机上并且是可用的
        if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
            String strurl = tranformStyle(urlPath);
            URL url = new URL(strurl);
            HttpURLConnection conn = null;
            conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(10000);
            // 获取到文件的大小
            int fileSize = conn.getContentLength() / 1024;         //KB
            System.setProperty("http.keepAlive", "false");
            InputStream is;
            if (conn.getResponseCode()==200){
                 is = conn.getInputStream();
            }else {
                 is = conn.getErrorStream();
            }
            String[] split = urlPath.split("/");
            String fileName = SDPath + split[split.length - 1];
            File file = new File(fileName);
            try {
                // 目录不存在创建目录
                if (!file.getParentFile().exists()) {
                    file.getParentFile().mkdirs();
                }
            } catch (Exception e) {
                // TODO: handle exception
            }
            FileOutputStream fos = new FileOutputStream(file);
            BufferedInputStream bis = new BufferedInputStream(is);
            byte[] buffer = new byte[1024];
            int len;
            while ((len = bis.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            bis.close();
            is.close();
            conn.disconnect();
            uriPath = file.getAbsolutePath();
        } else {
            throw new IOException("未发现有SD卡");
        }

        return uriPath;
    }



    /**
     * 对中文字符进行UTF-8编码
     * @param source 要转义的字符串
     * @return
     * @throws UnsupportedEncodingException
     */
    public static String tranformStyle(String source) throws UnsupportedEncodingException
    {
        char[] arr = source.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < arr.length; i++)
        {
            char temp = arr[i];
            if(isChinese(temp))
            {
                sb.append(URLEncoder.encode("" + temp, "UTF-8"));
                continue;
            }
            sb.append(arr[i]);
        }
        return sb.toString();
    }

    /**
     * 获取字符的编码值
     * @param s
     * @return
     * @throws UnsupportedEncodingException
     */
    public static int getValue(char s) throws UnsupportedEncodingException
    {
        String temp = (URLEncoder.encode("" + s, "GBK")).replace("%", "");
        if(temp.equals(s + ""))
        {
            return 0;
        }
        char[] arr = temp.toCharArray();
        int total = 0;
        for(int i = 0; i < arr.length; i++)
        {
            try
            {
                int t = Integer.parseInt((arr[i] + ""), 16);
                total = total * 16 + t;
            }
            catch(NumberFormatException e)
            {
                e.printStackTrace();
                return 0;
            }
        }
        return total;
    }

    /**
     * 判断是不是中文字符
     * @param c
     * @return
     */
    public static boolean isChinese(char c)
    {

        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);

        if(ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS

                || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS

                || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A

                || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION

                || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION

                || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS)
        {

            return true;

        }

        return false;

    }
}