Java Code Examples for android.util.Base64

private static Map<String, Object> defaultsToMap(JSONObject object) throws JSONException {
    final Map<String, Object> map = new HashMap<String, Object>();

    for (Iterator<String> keys = object.keys(); keys.hasNext(); ) {
        String key = keys.next();
        Object value = object.get(key);

        if (value instanceof Integer) {
            // setDefaults() takes Longs
            value = Long.valueOf((Integer) value);
        } else if (value instanceof JSONArray) {
            JSONArray array = (JSONArray) value;
            if (array.length() == 1 && array.get(0) instanceof String) {
                //parse byte[] as Base64 String
                value = Base64.decode(array.getString(0), Base64.DEFAULT);
            } else {
                //parse byte[] as numeric array
                byte[] bytes = new byte[array.length()];
                for (int i = 0; i < array.length(); i++)
                    bytes[i] = (byte) array.getInt(i);
                value = bytes;
            }
        }

        map.put(key, value);
    }
    return map;
}
 

public Object getObject(String str) {
    try {
        Object string = getString(str);
        if (TextUtils.isEmpty(string)) {
            return null;
        }
        ObjectInputStream objectInputStream = new ObjectInputStream(new ByteArrayInputStream
                (Base64.decode(string, 2)));
        string = objectInputStream.readObject();
        objectInputStream.close();
        return string;
    } catch (Throwable th) {
        Ln.w(th);
        return null;
    }
}
 

/**
 * 按照默认设置的压缩质量
 * 将 Bitmap  转换为 Base64 照片字符串
 *
 * @param bmp
 * @return
 */
public static final Observable<String> bmpToBase64(Bitmap bmp) {
    int quality = 100;

    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) { // 4.0 及以下
        quality = 50;
    }

    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN_MR2) { // 4.3 及以下
        quality = 60;
    }

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) { // 5.0 以下
        quality = 70;
    }

    return bmpToBase64(bmp, Bitmap.CompressFormat.JPEG, quality, Base64.NO_WRAP);
}
 

/**
 * An aes key derived from a base64 encoded key. This does not generate the
 * key. It's not random or a PBE key.
 *
 * @param keysStr a base64 encoded AES key / hmac key as base64(aesKey) : base64(hmacKey).
 * @return an AES & HMAC key set suitable for other functions.
 */
public static SecretKeys keys(String keysStr) throws InvalidKeyException {
    String[] keysArr = keysStr.split(":");

    if (keysArr.length != 2) {
        throw new IllegalArgumentException("Cannot parse aesKey:hmacKey");

    } else {
        byte[] confidentialityKey = Base64.decode(keysArr[0], BASE64_FLAGS);
        if (confidentialityKey.length != AES_KEY_LENGTH_BITS /8) {
            throw new InvalidKeyException("Base64 decoded key is not " + AES_KEY_LENGTH_BITS + " bytes");
        }
        byte[] integrityKey = Base64.decode(keysArr[1], BASE64_FLAGS);
        if (integrityKey.length != HMAC_KEY_LENGTH_BITS /8) {
            throw new InvalidKeyException("Base64 decoded key is not " + HMAC_KEY_LENGTH_BITS + " bytes");
        }

        return new SecretKeys(
                new SecretKeySpec(confidentialityKey, 0, confidentialityKey.length, CIPHER),
                new SecretKeySpec(integrityKey, HMAC_ALGORITHM));
    }
}
 

/**
 * 加密数据
 *
 * @param str str
 * @return 加密失败可能为null
 */
public static String encryptStr(String str) {

    try {
        PublicKey publicKey = getPublicKey(RSA_MODULUS,
                RSA_PUBLIC_EXPONENT);
        // 加解密类
        Cipher cipher = Cipher.getInstance("RSA"); // "RSA/ECB/PKCS1Padding"
        // 加密
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        byte[] dataEncode = cipher.doFinal(str.getBytes());
        // 为了可读性，转为Base64，
        byte[] tmp = Base64.encode(dataEncode, BASE64_FLAGS);
        return new String(tmp);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;

}
 

private String i(String str) {
    ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(str.getBytes());
    OutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    String str2 = null;
    try {
        GZIPOutputStream gZIPOutputStream = new GZIPOutputStream(byteArrayOutputStream);
        byte[] bArr = new byte[1024];
        while (true) {
            int read = byteArrayInputStream.read(bArr, 0, 1024);
            if (read == -1) {
                break;
            }
            gZIPOutputStream.write(bArr, 0, read);
        }
        gZIPOutputStream.flush();
        gZIPOutputStream.close();
        byte[] toByteArray = byteArrayOutputStream.toByteArray();
        byteArrayOutputStream.flush();
        byteArrayOutputStream.close();
        byteArrayInputStream.close();
        str2 = Base64.encodeToString(toByteArray, 2);
    } catch (Throwable e) {
        Ln.e(e);
    }
    return str2;
}
 

/**
 * 将对象储存到sharepreference
 *
 * @param key
 * @param device
 * @param <T>
 */
public static <T> boolean saveDeviceData(Context context, String key, T device) {
    if (mSharedPreferences == null) {
        mSharedPreferences = context.getSharedPreferences(SP_NAME, Context.MODE_PRIVATE);
    }
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    try {   //Device为自定义类
        // 创建对象输出流，并封装字节流
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        // 将对象写入字节流
        oos.writeObject(device);
        // 将字节流编码成base64的字符串
        String oAuth_Base64 = new String(Base64.encode(baos
                .toByteArray(), Base64.DEFAULT));
        mSharedPreferences.edit().putString(key, oAuth_Base64).commit();
        return true;
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }
}
 

public static String textCompress(String str) {
    try {
        Object array = ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(str.length()).array();
        OutputStream byteArrayOutputStream = new ByteArrayOutputStream(str.length());
        GZIPOutputStream gZIPOutputStream = new GZIPOutputStream(byteArrayOutputStream);
        gZIPOutputStream.write(str.getBytes("UTF-8"));
        gZIPOutputStream.close();
        byteArrayOutputStream.close();
        Object obj = new byte[(byteArrayOutputStream.toByteArray().length + 4)];
        System.arraycopy(array, 0, obj, 0, 4);
        System.arraycopy(byteArrayOutputStream.toByteArray(), 0, obj, 4, byteArrayOutputStream.toByteArray().length);
        return Base64.encodeToString(obj, 8);
    } catch (Exception e) {
        return "";
    }
}
 

public HttpPeerConnector(String peerUrl, SiteToSiteClientConfig siteToSiteClientConfig, SiteToSiteRemoteCluster siteToSiteRemoteCluster) {
    this.peerUrl = peerUrl;
    this.siteToSiteClientConfig = siteToSiteClientConfig;
    this.siteToSiteRemoteCluster = siteToSiteRemoteCluster;
    SSLContext sslContext = siteToSiteRemoteCluster.getSslContext();
    if (sslContext != null) {
        socketFactory = sslContext.getSocketFactory();
    } else {
        socketFactory = null;
    }
    proxy = getProxy(siteToSiteRemoteCluster);
    String proxyUsername = siteToSiteRemoteCluster.getProxyUsername();
    if (proxy != null && proxyUsername != null && !proxyUsername.isEmpty()) {
        proxyAuth = siteToSiteRemoteCluster.getProxyAuthorizationType() + " " + Base64.encodeToString((proxyUsername + ":" + siteToSiteRemoteCluster.getProxyPassword()).getBytes(Charsets.ISO_8859_1), Base64.DEFAULT);
    } else {
        proxyAuth = null;
    }
}
 

private void processIniciatorState1(int accountId, int peerId, @NonNull KeyExchangeSession session, @NonNull ExchangeMessage message) {
    String hisAesKey = message.getAesKey();
    PrivateKey myPrivateKey = session.getMyPrivateKey();

    try {
        byte[] hisAesEncoded = Base64.decode(hisAesKey, Base64.DEFAULT);
        String hisOriginalAes = CryptHelper.decryptRsa(hisAesEncoded, myPrivateKey);
        session.setHisAesKey(hisOriginalAes);

        String myOriginalAesKey = CryptHelper.generateRandomAesKey(Version.ofCurrent().getAesKeySize());
        session.setMyAesKey(myOriginalAesKey);

        PublicKey hisPublicKey = CryptHelper.createRsaPublicKeyFromString(message.getPublicKey());
        byte[] myEncodedAesKey = CryptHelper.encryptRsa(myOriginalAesKey, hisPublicKey);
        String myEncodedAesKeyBase64 = Base64.encodeToString(myEncodedAesKey, Base64.DEFAULT);

        Logger.d(TAG, "processIniciatorState1, myOriginalAesKey: " + myOriginalAesKey + ", hisOriginalAes: " + hisOriginalAes);

        ExchangeMessage m = new ExchangeMessage.Builder(Version.CURRENT, session.getId(), SessionState.INITIATOR_STATE_2)
                .setAesKey(myEncodedAesKeyBase64)
                .create();
        sendMessage(accountId, peerId, m);
    } catch (InvalidKeyException | BadPaddingException | IllegalBlockSizeException | NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeySpecException e) {
        e.printStackTrace();
    }
}
 

/**
 * Decode the user's email address from Base64
 *
 * @param accountList the {@link SaiyAccountList} object
 * @return the updated {@link SaiyAccountList}
 */
private static SaiyAccountList decode(@NonNull final SaiyAccountList accountList) {

    try {

        for (final SaiyAccount account : accountList.getSaiyAccountList()) {
            account.setAccountName(new String(Base64.decode(account.getAccountName(), Base64.NO_WRAP),
                    Constants.ENCODING_UTF8));
        }

    } catch (final UnsupportedEncodingException e) {
        if (DEBUG) {
            MyLog.w(CLS_NAME, "encode UnsupportedEncodingException");
            e.printStackTrace();
        }
    }

    return accountList;
}
 

public String getStringImage(Bitmap bmp){
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bmp.compress(Bitmap.CompressFormat.JPEG, 100, baos);
    byte[] imageBytes = baos.toByteArray();
    String encodedImage = Base64.encodeToString(imageBytes, Base64.DEFAULT);
    return encodedImage;
}
 

void getImage()                                                                                 //profile pic
    {
        ImageRequest request = new ImageRequest("http://ec2-52-14-50-89.us-east-2.compute.amazonaws.com/static/userdata/"+name+"/thumb.png",     ///"+email+" in btw userdata/  /thumb.png
                new Response.Listener<Bitmap>() {
                    @Override
                    public void onResponse(Bitmap bitmap) {
                        pro=bitmap;
                        ByteArrayOutputStream baos=new  ByteArrayOutputStream();
                        bitmap.compress(Bitmap.CompressFormat.PNG,100, baos);
                        byte [] b=baos.toByteArray();
                        String temp= Base64.encodeToString(b, Base64.DEFAULT);

                        SharedPreferences.Editor editor=sharedPreferences.edit();
                        editor.putString("profile_pic",temp);
                        editor.commit();
                        Log.e("mytag","Saved propic"+pro);
                        //count++;
                    }
                }, 0, 0, null,
                new Response.ErrorListener() {
                    public void onErrorResponse(VolleyError error) {
                        // mImageView.setImageResource(R.drawable.image_load_error);
                        Log.e("Home_Acitivity","No img found");
                        //count++;
                    }
                });
//        MySingleton.getMyInstance(getApplicationContext()).addToReqQue(request);
        RequestQueue queue= Volley.newRequestQueue(getApplicationContext());
        queue.add(request);
    }
 

public static String decrypt( String password, String encryptedData ) throws Exception 
{
	byte[] secretKey = generateKey( password.getBytes() );
	
	SecretKeySpec secretKeySpec = new SecretKeySpec( secretKey, CIPHER_ALGORITHM );
	Cipher cipher = Cipher.getInstance( CIPHER_ALGORITHM );
    cipher.init( Cipher.DECRYPT_MODE, secretKeySpec );
    
    byte[] encrypted = Base64.decode( encryptedData, Base64.DEFAULT );
    byte[] decrypted = cipher.doFinal( encrypted );
    
	return new String( decrypted );
}
 

public void setHTML(byte bytes[])
{
	//  preserve zoom level between pages

	int zoom = (int)(100 * mScale);

	String b64 = Base64.encodeToString(bytes, Base64.DEFAULT);
	loadData(b64, "text/html; charset=utf-8", "base64");

	setInitialScale(zoom);
	scrollTo(0, 0);
}
 

public static Bitmap decodeImage(String imageString) {
    try {
        byte[] encodeByte = Base64.decode(imageString, Base64.DEFAULT);
        Bitmap bitmap = BitmapFactory.decodeByteArray(encodeByte, 0, encodeByte.length);
        return bitmap;
    } catch (Exception e) {
        e.getMessage();
        return null;
    }
}
 

private void injectLightBlueCSS(String mode) {
	try {
		InputStream inputStream = getAssets().open("light_blue_theme.css");
		byte[] buffer = new byte[inputStream.available()];
		inputStream.read(buffer);
		inputStream.close();
		webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
	} catch (Exception d) {
		d.printStackTrace();
	}
}
 

private void injectPinkCSS(String mode) {
    try {
        InputStream inputStream = getAssets().open("pink_theme.css");
        byte[] buffer = new byte[inputStream.available()];
        inputStream.read(buffer);
        inputStream.close();
        webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
    } catch (Exception d) {
        d.printStackTrace();
    }
}
 

public SpannableStringBuilder processCrontab() {
    SpannableStringBuilder ret = new SpannableStringBuilder();
    String hashedTab = "";
    try {
        MessageDigest messageDigest = MessageDigest.getInstance(HASH_ALGO);
        messageDigest.update(crontab.getBytes());
        hashedTab = Base64.encodeToString(messageDigest.digest(), Base64.DEFAULT).trim();
    }
    catch (NoSuchAlgorithmException e) {
        Log.e(TAG, String.format("Algorithm %s not found:", HASH_ALGO));
        e.printStackTrace();
    }
    if (!hashedTab.equals(sharedPrefs.getString(PREF_CRONTAB_HASH, ""))
            && !crontab.equals("")) {
        // only schedule when enabled
        if (sharedPrefs.getBoolean(PREF_ENABLED, false)) {
            IO.logToLogFile(context.getString(R.string.log_crontab_change_detected));
            scheduleCrontab();
        }
        // save in any case such that on installation the crontab is not "new"
        sharedPrefs.edit().putString(PREF_CRONTAB_HASH, hashedTab).apply();
    }
    if (crontab.equals("")) {
        return ret;
    }
    for (String line : crontab.split("\n")){
        ret.append(line + "\n",
                new TypefaceSpan("monospace"), Spanned.SPAN_COMPOSING);
        ret.append(describeLine(line));
    }
    return ret;
}
 

public static String decrypt(String input) {
    if(input == null) return null;
    byte[] decrypted = null;
    try{
        SecretKeySpec skey = new SecretKeySpec(key.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, skey);
        decrypted = cipher.doFinal(Base64.decode(input, Base64.DEFAULT));
    } catch(Exception e){
        e.printStackTrace();
    }
    return new String(decrypted);
}
 

private void injectDarkCSS(String mode) {
	try {
		InputStream inputStream = getAssets().open("black.css");
		byte[] buffer = new byte[inputStream.available()];
		inputStream.read(buffer);
		inputStream.close();
		webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
	} catch (Exception b) {
		b.printStackTrace();
	}
}
 

private static PendingInstallShortcutInfo decode(String encoded, Context context) {
    try {
        JSONObject object = (JSONObject) new JSONTokener(encoded).nextValue();
        Intent launcherIntent = Intent.parseUri(object.getString(LAUNCH_INTENT_KEY), 0);

        if (object.optBoolean(APP_SHORTCUT_TYPE_KEY)) {
            // The is an internal launcher target shortcut.
            UserHandleCompat user = UserManagerCompat.getInstance(context)
                    .getUserForSerialNumber(object.getLong(USER_HANDLE_KEY));
            if (user == null) {
                return null;
            }

            LauncherActivityInfoCompat info = LauncherAppsCompat.getInstance(context)
                    .resolveActivity(launcherIntent, user);
            return info == null ? null : new PendingInstallShortcutInfo(info, context);
        }

        Intent data = new Intent();
        data.putExtra(Intent.EXTRA_SHORTCUT_INTENT, launcherIntent);
        data.putExtra(Intent.EXTRA_SHORTCUT_NAME, object.getString(NAME_KEY));

        String iconBase64 = object.optString(ICON_KEY);
        String iconResourceName = object.optString(ICON_RESOURCE_NAME_KEY);
        String iconResourcePackageName = object.optString(ICON_RESOURCE_PACKAGE_NAME_KEY);
        if (iconBase64 != null && !iconBase64.isEmpty()) {
            byte[] iconArray = Base64.decode(iconBase64, Base64.DEFAULT);
            Bitmap b = BitmapFactory.decodeByteArray(iconArray, 0, iconArray.length);
            data.putExtra(Intent.EXTRA_SHORTCUT_ICON, b);
        } else if (iconResourceName != null && !iconResourceName.isEmpty()) {
            Intent.ShortcutIconResource iconResource =
                new Intent.ShortcutIconResource();
            iconResource.resourceName = iconResourceName;
            iconResource.packageName = iconResourcePackageName;
            data.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE, iconResource);
        }

        return new PendingInstallShortcutInfo(data, context);
    } catch (JSONException | URISyntaxException e) {
        Log.d(TAG, "Exception reading shortcut to add: " + e);
    }
    return null;
}
 

private String createBody() {
  String sSPS;
  String sPPS;
  if (sps != null && pps != null) {
    sSPS = Base64.encodeToString(sps, 0, sps.length, Base64.NO_WRAP);
    sPPS = Base64.encodeToString(pps, 0, pps.length, Base64.NO_WRAP);
  } else {
    sSPS = defaultSPS;
    sPPS = defaultPPS;
  }
  return "v=0\r\n"
      +
      // TODO: Add IPV6 support
      "o=- "
      + timestamp
      + " "
      + timestamp
      + " IN IP4 "
      + "127.0.0.1"
      + "\r\n"
      + "s=Unnamed\r\n"
      + "i=N/A\r\n"
      + "c=IN IP4 "
      + host
      + "\r\n"
      +
      // means the session is permanent
      "t=0 0\r\n"
      + "a=recvonly\r\n"
      + Body.createAudioBody(trackAudio, sampleRate, isStereo)
      + Body.createVideoBody(trackVideo, sSPS, sPPS);
}
 

/** Checks whether given plaintext password corresponds 
    to a stored salted hash of the password. */
public static boolean check(String password, String stored) throws Exception{
    String[] saltAndPass = stored.split("\\$");
    if (saltAndPass.length != 2) {
        throw new IllegalStateException(
            "The stored password have the form 'salt$hash'");
    }
    String hashOfInput = hash(password, Base64.decode(saltAndPass[0], Base64.DEFAULT));
    return hashOfInput.equals(saltAndPass[1]);
}
 

/**
 * Encodes this ciphertext, IV, mac as a string.
 *
 * @return base64(iv) : base64(mac) : base64(ciphertext).
 * The iv and mac go first because they're fixed length.
 */
@Override
public String toString() {
    String ivString = Base64.encodeToString(iv, BASE64_FLAGS);
    String cipherTextString = Base64.encodeToString(cipherText, BASE64_FLAGS);
    String macString = Base64.encodeToString(mac, BASE64_FLAGS);
    return String.format(ivString + ":" + macString + ":" + cipherTextString);
}
 

/**
 * AES加密
 * @param input 加密字符串
 * @param key 密钥,密钥必须是16位的
 * @return
 */
public static String encrypt(@NonNull String input, @NonNull String key){
  byte[] crypted = null;
  try{
	  SecretKeySpec skey = new SecretKeySpec(key.getBytes(), "AES");
      Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
      cipher.init(Cipher.ENCRYPT_MODE, skey);
      crypted = cipher.doFinal(input.getBytes());
    }catch(Exception e){
    	System.out.println(e.toString());
    }
    return new String(Base64.encode(crypted, Base64.DEFAULT));
}
 

/**
 * Decodes the encodedPhoto and sets the photo Bitmap to it.
 */
private void decodePhoto() {
    if (this.encodedPhoto != null) {
        byte [] decodedBytes = Base64.decode(this.encodedPhoto, 0);
        this.photo = BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.length);
    }
}
 

private void injectGPlusCSS(String mode) {
    try {
        InputStream inputStream = getAssets().open("gplus_theme.css");
        byte[] buffer = new byte[inputStream.available()];
        inputStream.read(buffer);
        inputStream.close();
        webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
    } catch (Exception d) {
        d.printStackTrace();
    }
}
 

private void injectDefaultCSS(String mode) {
    try {
        InputStream inputStream = getAssets().open("fbdefault.css");
        byte[] buffer = new byte[inputStream.available()];
        inputStream.read(buffer);
        inputStream.close();
        webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
    } catch (Exception fb) {
        fb.printStackTrace();
    }
}
 

private void getActions(final DeviceDAO device) {
    Log.d(TAG, "TODO getActions");
    String uri = Uri.parse(String.format("http://%s:%s/", device.getIP(), device.getPort()))
            .buildUpon().build().toString();
    String credentials = device.getUsername() + ":" + device.getPassword();
    byte[] t = credentials.getBytes();
    byte[] auth = Base64.encode(t, Base64.DEFAULT);
    final String basicAuthValue = new String(auth);
    requestQueue.add(new StringRequest(Request.Method.POST, uri, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
        }
    }) {
        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String, String> params = new HashMap<>();
            params.put("Authorization", "Basic " + basicAuthValue);
            params.put("Connection", "close");
            return params;
        }
    });
}
 

public static Server decode(String data)
{
    final String[] split = data.split(";");
    final String name = new String(Base64.decode(split[0], Base64.DEFAULT));
    final String uuid = split[1];
    return new Server(name, uuid);
}
 

/**
 * 用公钥解密
 *
 * @param data 加密数据
 * @param key  密钥
 * @return
 * @throws Exception
 */
public static String decryptByPublicKey(String data, String key) throws Exception {
    //对私钥解密
    byte[] keyBytes = Base64.decode(key.getBytes(), Base64.DEFAULT);
    X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    Key publicKey = keyFactory.generatePublic(x509EncodedKeySpec);

    //对数据解密
    Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    cipher.init(Cipher.DECRYPT_MODE, publicKey);
    byte[] dataBytes = Base64.decode(data.getBytes(), Base64.DEFAULT);
    byte[] resultBytes = cipher.doFinal(dataBytes);
    return new String(resultBytes, "UTF-8");
}
 

private static String bitmapToBase64(Bitmap bitmap) {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
    byte[] byteArray = stream.toByteArray();
    IOUtils.closeQuietly(stream);
    return "data:image/png;base64," + Base64.encodeToString(byteArray, Base64.DEFAULT);
}
 

/**
 * Checks whether underlying platform supports extended WebPs
 */
private static boolean isExtendedWebpSupported() {
  // Lossless and extended formats are supported on Android 4.2.1+
  // Unfortunately SDK_INT is not enough to distinguish 4.2 and 4.2.1
  // (both are API level 17 (JELLY_BEAN_MR1))
  if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
    return false;
  }

  if (Build.VERSION.SDK_INT == Build.VERSION_CODES.JELLY_BEAN_MR1) {
    // Let's test if extended webp is supported
    // To this end we will try to decode bounds of vp8x webp with alpha channel
    byte[] decodedBytes = Base64.decode(VP8X_WEBP_BASE64, Base64.DEFAULT);
    BitmapFactory.Options opts = new BitmapFactory.Options();
    opts.inJustDecodeBounds = true;
    BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.length, opts);

    // If Android managed to find appropriate decoder then opts.outHeight and opts.outWidth
    // should be set. We can not assume that outMimeType is set.
    // Android guys forgot to update logic for mime types when they introduced support for webp.
    // For example, on 4.2.2 this field is not set for webp images.
    if (opts.outHeight != 1 || opts.outWidth != 1) {
      return false;
    }
  }

  return true;
}
 

public boolean generateBase64FromImage() {
    try {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        yuvImage.compressToJpeg(person.getFaceBounds(), 50, outputStream);
        this.jpeg = outputStream.toByteArray();
        this.b64 = Base64.encodeToString(jpeg, Base64.DEFAULT);
    } catch (Exception e) {
        Log.d(TAG, "Exception while compressing YUVImage into JPEG - " + e.getMessage());
    } finally {
        return (b64 != null);
    }
}
 

public static String decodeString(String text) {
    try {
        return new String(Base64.decode(text, Base64.DEFAULT), "UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
        return null;
    }
}
 

public static String encodeImage(Bitmap bitmap) {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
    byte[] b = baos.toByteArray();
    String temp = Base64.encodeToString(b, Base64.DEFAULT);
    return temp;
}
 

private OpenForReadResult readDataUri(Uri uri) {
    String uriAsString = uri.getSchemeSpecificPart();
    int commaPos = uriAsString.indexOf(',');
    if (commaPos == -1) {
        return null;
    }
    String[] mimeParts = uriAsString.substring(0, commaPos).split(";");
    String contentType = null;
    boolean base64 = false;
    if (mimeParts.length > 0) {
        contentType = mimeParts[0];
    }
    for (int i = 1; i < mimeParts.length; ++i) {
        if ("base64".equalsIgnoreCase(mimeParts[i])) {
            base64 = true;
        }
    }
    String dataPartAsString = uriAsString.substring(commaPos + 1);
    byte[] data;
    if (base64) {
        data = Base64.decode(dataPartAsString, Base64.DEFAULT);
    } else {
        try {
            data = dataPartAsString.getBytes("UTF-8");
        } catch (UnsupportedEncodingException e) {
            data = dataPartAsString.getBytes();
        }
    }
    InputStream inputStream = new ByteArrayInputStream(data);
    return new OpenForReadResult(uri, inputStream, contentType, data.length, null);
}
 

private void showFbBar(String mode) {
    try {
        InputStream inputStream = getAssets().open("showfbar.css");
        byte[] buffer = new byte[inputStream.available()];
        inputStream.read(buffer);
        inputStream.close();
        webView.loadUrl("javascript:(function() {var parent = document.getElementsByTagName('head').item(0);var style = document.createElement('style');style.type = 'text/css';style.innerHTML = window.atob('" + Base64.encodeToString(buffer, 2) + "');" + "parent.appendChild(style)" + "})()");
    } catch (Exception d) {
        d.printStackTrace();
    }
}
 

/**
 * string转成bitmap
 *
 * @param str 需要转换的字符串
 * @return 失败时为null
 */
public static Bitmap str2Bitmap(String str) {
    Bitmap bitmap = null;
    try {
        byte[] bitmapArray = Base64.decode(str, Base64.DEFAULT);
        bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0,
                bitmapArray.length);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return bitmap;
}