1.图片-base64解码工具类如下。

注意：base64转成Bitmap时，需要去除所有"/r/n"、"data:image/png;base64,"字符，否则会造成解码失败，Bitmap为空的情况。

public class TypeConverter {
    //图片转化成base64字符串
    public static String imageEncode(String path) {
        //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
        InputStream in = null;
        byte[] data = null;
        //读取图片字节数组
        try {
            in = new FileInputStream(new File(path));
            data = new byte[in.available()];
            in.read(data);
            in.close();
        catch (IOException e)
            e.printStackTrace();
        //对字节数组Base64编码
        return Base64.encodeToString(data, Base64.DEFAULT);//返回Base64编码过的字节数组字符串
    //base64字符串转化成图片
    public static String imageDecode(Context context, String imgStr,String imagePath,String imageName) {
        imgStr = imgStr.replaceAll("/r/ndata:image/png;base64,","");
        //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 "";
        //Base64解码
        byte[] b = Base64.decode(imgStr,Base64.DEFAULT);
        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 = context.getExternalCacheDir().getPath()+"/hema_card.jpg";//新生成的图片
        String imgFilePath = imagePath+"/"+imageName;//新生成的图片
        LogUtils.e("生成的图片地址为："+imgFilePath);
        OutputStream out = null;
        try {
            out = new FileOutputStream(imgFilePath);
            out.write(b);
            out.flush();
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        // 其次把文件插入到系统图库
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(),
                    imagePath, imageName, null);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        // 最后通知图库更新
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://"+imgFilePath)));
        return imgFilePath;
     * bitmap转为base64
     * @param bitmap
     * @return
    public static String bitmapToBase64(Bitmap bitmap) {
        String result = null;
        ByteArrayOutputStream baos = null;
        try {
            if (bitmap != null) {
                baos = new ByteArrayOutputStream();
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
                baos.flush();
                baos.close();
                byte[] bitmapBytes = baos.toByteArray();
                result = Base64.encodeToString(bitmapBytes, Base64.DEFAULT);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (baos != null) {
                    baos.flush();
                    baos.close();
            } catch (IOException e) {
                e.printStackTrace();
        return result;
     * base64转为bitmap
     * @param base64Data
     * @return
    public static Bitmap base64ToBitmap(String base64Data) {
        base64Data = base64Data.replace("data:image/png;base64,","");
        byte[] bytes = Base64.decode(base64Data, Base64.DEFAULT);
        return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
2.存储文件至指定路径。
 2.1.添加存储权限。　
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
2.2.保存图片，并通知相册刷新。
 public static void saveImageToGallery(Context context, Bitmap bitmap, String fileName,String toast){
        // 首先保存图片
        File file = new File(Environment.getExternalStorageDirectory().getPath()+"/"+fileName);//log: storage/emulated/0/hema2.jpg
        try {
            if(!file.exists()){
                file.createNewFile();
            FileOutputStream fos = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
            fos.flush();
            fos.close();
            if(!TextUtils.isEmpty(toast)){
                ToastUtils.showToast(toast);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        // 其次把文件插入到系统图库
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(),
                    file.getAbsolutePath(), fileName, null);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        // 最后通知图库更新
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://"+file.getPath())));
参考博客：
1.https://blog.csdn.net/chunlongyuan/article/details/7696070
2.https://blog.csdn.net/wolfking0608/article/details/79289799#commentBox