从 SQLite 存储和检索图像 - blob答案

【问题标题】：Storing and retrieving image from SQLite - blob从 SQLite 存储和检索图像 - blob
【发布时间】：2015-11-21 10:49:33
【问题描述】：

我正在尝试在离线模式下显示用户个人资料详细信息。姓名、图片、地址、邮箱等基本信息。

我已经阅读了blob，并将图像以字节数组的形式保存在blob中。

现在在检索时，我已将字节数组转换为位图，它始终为空。 :(

代码 sn-p：

点击按钮时从图库中选择图片：

photo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                Intent photoPickerIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                photoPickerIntent.setType("image/*");
                startActivityForResult(photoPickerIntent, RESULT_LOAD_IMG);
            }
        });

获取图像并将其转换为字符串和字节数组：

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data); 
        try
        { 
            if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK && null != data)
            { 
                Uri selectedImage = data.getData();
                String[] filePathColumn = { MediaStore.Images.Media.DATA }; 
                Cursor cursor = getContentResolver().query(selectedImage,
                        filePathColumn, null, null, null); 
                cursor.moveToFirst();
                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                imgPath = cursor.getString(columnIndex);
                cursor.close(); 
                String fileNameSegments[] = imgPath.split("/");
                fileName = fileNameSegments[fileNameSegments.length - 1]; 
                BitmapFactory.Options options = null;
                options = new BitmapFactory.Options();
                options.inSampleSize = 3;
                bitmap = BitmapFactory.decodeFile(imgPath,options);
                ByteArrayOutputStream stream = new ByteArrayOutputStream(); 
                BitmapFactory.Options o = new BitmapFactory.Options();
                o.inJustDecodeBounds = true;
                BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o); 
                final int REQUIRED_SIZE = 140; 
                int width_tmp = o.outWidth, height_tmp = o.outHeight;
                int scale = 1;
                while (true) {
                    if (width_tmp / 2 < REQUIRED_SIZE
                            || height_tmp / 2 < REQUIRED_SIZE) {
                        break;
                    }
                    width_tmp /= 2;
                    height_tmp /= 2;
                    scale *= 2;
                }

                BitmapFactory.Options o2 = new BitmapFactory.Options();
                o2.inSampleSize = scale;

                bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o2); 
                images.setImageBitmap(BitmapFactory.decodeFile(imgPath)); 
                images.setVisibility(View.VISIBLE); 
                ;

                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
                byte_arr = stream.toByteArray();

                encodedString = Base64.encodeToString(byte_arr, Base64.DEFAULT); 
            }
            else
            {
                Toast.makeText(this, "You haven't picked Image",
                        Toast.LENGTH_LONG).show();
            }
        } catch (Exception e) {
            Toast.makeText(this, "Something went wrong", Toast.LENGTH_LONG).show();
        }
    }

现在将基本细节和编码字符串发送到服务器以保存在数据库中。成功后，我会在 SQLite 中保存相同的详细信息。

@Override
        protected void onPostExecute(Void aVoid)
        {
            dialog1.dismiss();
            if(code==200)
            {
                Intent intent = new Intent(getApplicationContext(), SuccessfulLogin.class);
                startActivity(intent);
                finish(); 

                DBhelper dbHelper = new DBhelper(Edit.this);
                Employee employee_One = new Employee(byte_arr,  name.getText().toString(), mobile.getText().toString(),address.getText().toString(),birth.getText().toString(),UserID);
//                Employee employee_One = new Employee(byte_arr,  name.getText().toString(), mobile.getText().toString(),address.getText().toString(),city.getText().toString(),birth.getText().toString(),UserID);
                dbHelper.open();
                dbHelper.insertEmpDetails(employee_One);
                dbHelper.close();
                dbHelper.open();
                employee_One = dbHelper.retriveEmpDetails();
                dbHelper.close();
                /*
                Log.e("Edit Profile Details", "Address --" + employee_One.getAddress() + "\n name " + employee_One.getName()
                        + "\n Image " + Arrays.toString(employee_One.getBitmap()) + " \n mobile--" + employee_One.getPhoneNumber()
                        + "\n DOB " + (employee_One.getBirth()) + " \n email--" + employee_One.getEmail());

                Log.e("Profile Values", "Address --" + address.getText().toString() + "\n name " +
                        name.getText().toString() + "\n Image " + Arrays.toString(byte_arr) + " \n mobile--" +mobile.getText().toString());
*/
                Log.e("byte_arr", "" + Arrays.toString(byte_arr));

                Toast.makeText(getBaseContext(), "Details updated successfully..", Toast.LENGTH_LONG).show();
            }
            else
            {
                Toast.makeText(getBaseContext(), "Sorry, Try Again",Toast.LENGTH_LONG).show();
            }
            super.onPostExecute(aVoid);
        }

我在这里使用相同的字节数组。

员工构造函数：

public Employee(byte[] b, String n, String k, String a, String bt, String e)
    {
        bmp = b;
        Log.e("\nEmployee bmp", "" + Arrays.toString(this.bmp));
        name = n;
        _phone_number = k;
        _address = a; 
        _birth = bt;
        _email = e;
    }

在离线模式下检索数据：

if(isNetworkAvailable())
        {
            new DisplayDetails().execute(); 
        }
        else
        {
            DBhelper dbHelper = new DBhelper(ViewProfile.this);

            dbHelper.open();
            employee_One = dbHelper.retriveEmpDetails();
            dbHelper.close();

            Log.e("Profile Details", "Address --" + employee_One.getAddress() + "\n name " +
                    employee_One.getName() + "\n Image " + Arrays.toString(employee_One.getBitmap()) + " \n mobile--" + employee_One.getPhoneNumber());

            name.setText(employee_One.getName());
            address.setText(employee_One.getAddress());
            mobile.setText(employee_One.getPhoneNumber());
            birth.setText(employee_One.getBirth());
            email.setText(employee_One.getEmail());
            byte[] outImage=employee_One.getBitmap();
            ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
            Bitmap theImage = BitmapFactory.decodeStream(imageStream);
            Image.setImageBitmap(theImage);

            /*
            ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
            Bitmap theImage = BitmapFactory.decodeStream(imageStream);
            Image.setImageBitmap(theImage);

            ************

            ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
            Bitmap theImage = BitmapFactory.decodeStream(imageStream);
            Log.e("\nbitmap", "" + theImage +"\n outImage--" + Arrays.toString(outImage));

            ****************

            ByteArrayInputStream arrayInputStream = new ByteArrayInputStream(outImage);
            Bitmap bitmap = BitmapFactory.decodeStream(arrayInputStream);

            ******************

            int intByteCount = outImage.length;
            int[] intColors = new int[intByteCount / 3];
            int intWidth = 2;
            int intHeight = 2;
            final int intAlpha = 255;
            if ((intByteCount / 3) != (intWidth * intHeight)) {
                throw new ArrayStoreException();
            }
            for (int intIndex = 0; intIndex < intByteCount - 2; intIndex = intIndex + 3) {
                intColors[intIndex / 3] = (intAlpha << 24) | (outImage[intIndex] << 16) | (outImage[intIndex + 1] << 8) | outImage[intIndex + 2];
            }
            Bitmap bmpImage = Bitmap.createBitmap(intColors, intWidth, intHeight, Bitmap.Config.ARGB_8888);
            */

        }

我已经尝试了所有注释的代码。但是失败

每次我在位图中得到 null 并且图像没有分配给ImageView。同时我无法在我的表中添加超过 6 列。如果我尝试添加第 7 列，则会出现各种错误。

我不明白哪里出错了..

任何形式的帮助都将不胜感激。

谢谢。

日志

  Image array: [91, 45, 49, 44, 32, 45, 52, 48, 44, 32, 45, 49, 44, 32, 45, 51, 50, 44, 32, 48, 44, 32, 49, 54, 44, 32, 55, 52, 44, 32, 55, 48, 44, 32, 55, 51, 44, 32, 55, 48, 44, 32, 48, 44, 32, 49, 44, 32, 49, 44, 32, 48, 44, 32, 48, 44, 32, 49, 44, 32, 48, 44, 32, 49, 44, 32, 48, 44, 32, 48, 44, 32, 45, 49, 44, 32, 45, 51, 55, 44, 32, 48, 44, 32, 54, 55, 44, 32, 48, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 45, 49, 44, 32, 45, 51, 55, 44, 32, 48, 44, 32, 54, 55, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 45, 49, 44, 32, 45, 54, 52, 44, 32, 48, 44, 32, 49, 55, 44, 32, 56, 44, 32, 48, 44, 32, 45, 49, 48, 54, 44, 32, 48, 44, 32, 45, 53, 54, 44, 32, 51, 44, 32, 49, 44, 32, 51, 52, 44, 32, 48, 44, 32, 50, 44, 32, 49, 55, 44, 32, 49, 44, 32, 51, 44, 32, 49, 55, 44, 32, 49, 44, 32, 45, 49, 44, 32, 45, 54, 48, 44, 32, 48, 44, 32, 51, 49, 44, 32, 48, 44, 32, 48, 44, 32, 49, 44, 32, 53, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 49, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 48, 44, 32, 49, 44, 32, 50, 44, 32, 51, 44, 32, 52, 44, 32, 53, 44, 32, 54, 44, 32, 55, 44, 32, 56, 44, 32, 57, 44, 32, 49, 48, 44, 32, 49, 49, 44, 32, 45, 49, 44, 32, 45, 54, 48, 44, 32, 48, 44, 32, 45, 55, 53, 44, 32, 49, 54, 44, 32, 48, 44, 32, 50, 44, 32, 49, 44, 32, 51, 44, 32, 51, 44, 32, 50, 44, 32, 52, 44, 32, 51, 44, 32, 53, 44, 32, 53, 44, 32, 52, 44, 32, 52, 44, 32, 48, 44, 32, 48, 44, 32, 49, 44, 32, 49, 50, 53, 44, 32, 49, 44, 32, 50, 44, 32, 51, 44, 32, 48, 44, 32, 52, 44, 32, 49, 55, 44, 32, 53, 44, 32, 49, 56, 44, 32, 51, 51, 44, 32, 52, 57, 44, 32, 54, 53, 44, 32, 54, 44, 32, 49, 57, 44, 32, 56, 49, 44, 32, 57, 55, 44, 32, 55, 44, 32, 51, 52, 44, 32, 49, 49, 51, 44, 32, 50, 48, 44, 32, 53, 48, 44, 32, 45, 49, 50, 55, 44, 32, 45, 49, 49, 49, 44, 32, 45, 57, 53, 44, 32, 56, 44, 32, 51, 53, 44, 32, 54, 54, 44, 32, 45, 55, 57, 44, 32, 45, 54, 51, 44, 32, 50, 49, 44, 32, 56, 50, 44, 32, 45, 52, 55, 44, 32, 45, 49, 54, 44, 32, 51, 54, 44, 32, 53, 49, 44, 32, 57, 56, 44, 32, 49, 49, 52, 44, 32, 45, 49, 50, 54, 44, 32, 57, 44, 32, 49, 48, 44, 32, 50, 50, 44, 32, 50, 51, 44, 32, 50, 52, 44, 32, 50, 53, 44, 32, 50, 54, 44, 32, 51, 55, 44, 32, 51, 56, 44, 32, 51, 57, 44, 32, 52, 48, 44, 32, 52, 49, 44, 32, 52, 50, 44, 32, 53, 50, 44, 32, 53, 51, 44, 32, 53, 52, 44, 32, 53, 53, 44, 32, 53, 54, 44, 32, 53, 55, 44, 32, 53, 56, 44, 32, 54, 55, 44, 32, 54, 56, 44, 32, 54, 57, 44, 32, 55, 48, 44, 32, 55, 49, 44, 32, 55, 50, 44, 32, 55, 51, 44, 32, 55, 52, 44, 32, 56, 51, 44
 E/bitmap﹕ null

【问题讨论】：

这是因为在Db中保存任何类型的数据都有1MB的限制..而不是image..您可以将image保存在sdcard中..然后将image的路径保存在db中。

标签： android sqlite bitmap

【解决方案1】：

将 decodeStream 替换为 decodeByteArray：

Bitmap bitmap = BitmapFactory.decodeByteArray(theImage , 0, theImage.length);

【讨论】：

@Prabs 请记住将 picture.length 替换为 theImage.length，抱歉我之前错过了。
我已经添加了日志..再次为空

【解决方案2】：

在数据库中存在 1 MB 查询限制，以防止无意义的查询阻塞设备。

http://www.sqlite.org/intern-v-extern-blob.html

而是将您的图像保存在 SD 卡中......以及 sd 卡的 db 存储路径中。

【讨论】：

“在数据库中”没有这样的限制，您可以存储任何大小的数据，好的，有一些限制但更大：sqlite.org/limits.html
如果图像丢失（如果删除）？那么呢？
您可以将它们隐藏起来（“使用“点”和图像名称），这样任何人都无法删除它们
@pskink 同意 db 没有限制..它取决于内存..但是查询有限制..cursor..您从 db 获取的数据量..
好的..我正在关注你的答案..将图像保存在隐藏文件夹中..现在正在执行 sql 部分..一旦完成，我会告诉你..谢谢你展示另一种方式这样做