代码

Question

我想在SQLite数据库中存储较大的BLOBS或类似数据，因为现在我不能上传大小超过2mb的图像

此问题的解决方案是将我的图像存储在内部目录中，并且其路径是在SQLite DB中插入

过去3天，我一直在尝试解决此问题，因为我是Java的新手，而且我不知道如何存储它

如果您能帮助我解决这个问题，我将不胜感激

这是我的代码：

CrudActivity

    EditText mEdtName, mEdtStok, mEdtJual;
    Button mBtnAdd, mBtnList;
    ImageView mImageView;

    final int REQUEST_CODE_GALLERY = 999;

    public static SQLiteHelper mSQLiteHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_crud);

        mEdtName = findViewById(R.id.edtName);
        mEdtStok = findViewById(R.id.edtStok);
        mEdtJual = findViewById(R.id.edtJual);
        mBtnAdd = findViewById(R.id.btnAdd);
        mBtnList = findViewById(R.id.btnList);
        mImageView = findViewById(R.id.imageView);

        //creating database
        mSQLiteHelper = new SQLiteHelper(this, "RECORDDB.sqlite", null, 1);

        //creating table in database
        mSQLiteHelper.queryData("CREATE TABLE IF NOT EXISTS RECORD(id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, stok VARCHAR, jual VARCHAR, image BLOB)");


        //select image by on imageview click
        mImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //read external storage permission to select image from gallery
                //runtime permission for devices android 6.0 and above
                ActivityCompat.requestPermissions(
                        CrudActivity.this,
                        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                        REQUEST_CODE_GALLERY
                );
            }
        });

        //add record to sqlite
        mBtnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    mSQLiteHelper.insertData(
                            mEdtName.getText().toString().trim(),
                            mEdtStok.getText().toString().trim(),
                            mEdtJual.getText().toString().trim(),
                            imageViewToByte(mImageView)
                    );
                    Toast.makeText(CrudActivity.this, "Added successfully", Toast.LENGTH_SHORT).show();
                    //reset views
                    mEdtName.setText("");
                    mEdtStok.setText("");
                    mEdtJual.setText("");
                    mImageView.setImageResource(R.drawable.addphoto);
                }
                catch (Exception e){
                    e.printStackTrace();
                }
            }
        });

        //show record list
        mBtnList.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //start recordlist activity
                startActivity(new Intent(CrudActivity.this, RecordListActivity.class));
            }
        });


    }

    public static byte[] imageViewToByte(ImageView image) {
        Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
        byte[] byteArray = stream.toByteArray();
        return byteArray;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CODE_GALLERY){
            if (grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                //gallery intent
                Intent galleryIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
                galleryIntent.setType("image/*");
                startActivityForResult(galleryIntent, REQUEST_CODE_GALLERY);
            }
            else {
                Toast.makeText(this, "Don't have permission to access file location", Toast.LENGTH_SHORT).show();
            }
            return;
        }
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }



    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Intent intent;
        intent = new Intent(Intent.ACTION_GET_CONTENT);

        if (requestCode == REQUEST_CODE_GALLERY && resultCode == RESULT_OK){
            Uri imageUri = data.getData();
            final int takeFlags = intent.getFlags()
                    & (Intent.FLAG_GRANT_READ_URI_PERMISSION
                    | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
// Check for the freshest data.
            getContentResolver().takePersistableUriPermission(imageUri, takeFlags);
            CropImage.activity(imageUri)
                    .setGuidelines(CropImageView.Guidelines.ON) //enable image guidlines
                    .setAspectRatio(1,1)// image will be square
                    .start(this);

        }
        if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE){
            CropImage.ActivityResult result =CropImage.getActivityResult(data);
            if (resultCode == RESULT_OK){
                Uri resultUri = result.getUri();
                //set image choosed from gallery to image view
                mImageView.setImageURI(resultUri);
            }
            else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE){
                Exception error = result.getError();
            }

        }

        super.onActivityResult(requestCode, resultCode, data);
    }
}

SQLiteHelper

  public class SQLiteHelper extends SQLiteOpenHelper{

    //constructor
    SQLiteHelper(Context context,
                 String name,
                 SQLiteDatabase.CursorFactory factory,
                 int version){
        super(context, name, factory, version);
    }

    public void queryData(String sql){
        SQLiteDatabase database = getWritableDatabase();
        database.execSQL(sql);
    }

    //insertData
    public void insertData(String name, String stok, String jual, byte[] image){
        SQLiteDatabase database = getWritableDatabase();
        //query to insert record in database table
        String sql = "INSERT INTO RECORD VALUES(NULL, ?, ?, ?, ?)"; //where "RECORD" is table name in database we will create in mainActivity

        SQLiteStatement statement = database.compileStatement(sql);
        statement.clearBindings();

        statement.bindString(1, name);
        statement.bindString(2, stok);
        statement.bindString(3, jual);
        statement.bindBlob(4, image);

        statement.executeInsert();
    }

    //updateData
    public void updateData(String name, String stok, String jual, byte[] image, int id){
        SQLiteDatabase database = getWritableDatabase();
        //query to update record
        String sql = "UPDATE RECORD SET name=?, stok=?, jual=?, image=? WHERE id=?";

        SQLiteStatement statement = database.compileStatement(sql);

        statement.bindString(1, name);
        statement.bindString(2, stok);
        statement.bindString(3, jual);
        statement.bindBlob(4, image);
        statement.bindDouble(5, (double)id);

        statement.execute();
        database.close();
    }

    //deleteData
    public void deleteData(int id){
        SQLiteDatabase database = getWritableDatabase();
        //query to delete record using id
        String sql = "DELETE FROM RECORD WHERE id=?";

        SQLiteStatement statement = database.compileStatement(sql);
        statement.clearBindings();
        statement.bindDouble(1, (double)id);

        statement.execute();
        database.close();
    }

    public Cursor getData(String sql){
        SQLiteDatabase database = getReadableDatabase();
        return database.rawQuery(sql, null);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}

RecordListActivity

public class RecordListActivity extends AppCompatActivity {

    ListView mListView;
    ArrayList<Model> mList;
    RecordListAdapter mAdapter = null;

    ImageView imageViewIcon;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_record_list);

        mListView = findViewById(R.id.listView);
        mList = new ArrayList<>();
        mAdapter = new RecordListAdapter(this, R.layout.row, mList);
        mListView.setAdapter(mAdapter);

        //get all data from sqlite
        SQLiteHelper mSQLiteHelper = new SQLiteHelper(this, "RECORDDB.sqlite", null, 1);
        Cursor cursor = mSQLiteHelper.getData("SELECT * FROM RECORD");
        mList.clear();
        while (cursor.moveToNext()){
            int id = cursor.getInt(0);
            String name = cursor.getString(1);
            String stok = cursor.getString(2);
            String jual = cursor.getString(3);
            byte[] image  = cursor.getBlob(4);
            //add to list
            mList.add(new Model(id, name, stok, jual, image));
        }
        mAdapter.notifyDataSetChanged();
        if (mList.size()==0){
            //if there is no record in table of database which means listview is empty
            Toast.makeText(this, "No record found...", Toast.LENGTH_SHORT).show();
        }

        mListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> adapterView, View view, final int position, long l) {
                //alert dialog to display options of update and delete
                final CharSequence[] items = {"Update", "Delete"};

                AlertDialog.Builder dialog = new AlertDialog.Builder(RecordListActivity.this);

                dialog.setTitle("Choose an action");
                dialog.setItems(items, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        if (i == 0){
                            //update
                            Cursor c = CrudActivity.mSQLiteHelper.getData("SELECT id FROM RECORD");
                            ArrayList<Integer> arrID = new ArrayList<Integer>();
                            while (c.moveToNext()){
                                arrID.add(c.getInt(0));
                            }
                            //show update dialog
                            showDialogUpdate(RecordListActivity.this, arrID.get(position));
                        }
                        if (i==1){
                            //delete
                            Cursor c = CrudActivity.mSQLiteHelper.getData("SELECT id FROM RECORD");
                            ArrayList<Integer> arrID = new ArrayList<Integer>();
                            while (c.moveToNext()){
                                arrID.add(c.getInt(0));
                            }
                            showDialogDelete(arrID.get(position));
                        }
                    }
                });
                dialog.show();
                return true;
            }
        });


    }

    private void showDialogDelete(final int idRecord) {
        AlertDialog.Builder dialogDelete = new AlertDialog.Builder(RecordListActivity.this);
        dialogDelete.setTitle("Warning!!");
        dialogDelete.setMessage("Are you sure to delete?");
        dialogDelete.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                try {
                    CrudActivity.mSQLiteHelper.deleteData(idRecord);
                    Toast.makeText(RecordListActivity.this, "Delete successfully", Toast.LENGTH_SHORT).show();
                }
                catch (Exception e){
                    Log.e("error", e.getMessage());
                }
                updateRecordList();
            }
        });
        dialogDelete.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialogInterface.dismiss();
            }
        });
        dialogDelete.show();
    }

    private void showDialogUpdate(Activity activity, final int position){
        final Dialog dialog = new Dialog(activity);
        dialog.setContentView(R.layout.update_dialog);
        dialog.setTitle("Update");

        imageViewIcon = dialog.findViewById(R.id.imageViewRecord);
        final EditText edtName = dialog.findViewById(R.id.edtName);
        final EditText edtStok = dialog.findViewById(R.id.edtStok);
        final EditText edtJual = dialog.findViewById(R.id.edtJual);
        Button btnUpdate = dialog.findViewById(R.id.btnUpdate);

        //set width of dialog
        int width = (int)(activity.getResources().getDisplayMetrics().widthPixels*0.95);
        //set hieght of dialog
        int height = (int)(activity.getResources().getDisplayMetrics().heightPixels*0.7);
        dialog.getWindow().setLayout(width,height);
        dialog.show();

        //in update dialog click image view to update image
        imageViewIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //check external storage permission
                ActivityCompat.requestPermissions(
                        RecordListActivity.this,
                        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                        888
                );
            }
        });
        btnUpdate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    CrudActivity.mSQLiteHelper.updateData(
                            edtName.getText().toString().trim(),
                            edtStok.getText().toString().trim(),
                            edtJual.getText().toString().trim(),
                            CrudActivity.imageViewToByte(imageViewIcon),
                            position
                    );
                    dialog.dismiss();
                    Toast.makeText(getApplicationContext(), "Update Successfull", Toast.LENGTH_SHORT).show();
                }
                catch (Exception error){
                    Log.e("Update error", error.getMessage());
                }
                updateRecordList();
            }
        });

    }

    private void updateRecordList() {
        //get all data from sqlite
        Cursor cursor = CrudActivity.mSQLiteHelper.getData("SELECT * FROM RECORD");
        mList.clear();
        while (cursor.moveToNext()){
            int id = cursor.getInt(0);
            String name = cursor.getString(1);
            String stok = cursor.getString(2);
            String jual = cursor.getString(3);
            byte[] image = cursor.getBlob(4);

            mList.add(new Model(id,name,stok,jual,image));
        }
        mAdapter.notifyDataSetChanged();
    }


    public static byte[] imageViewToByte(ImageView image) {
        Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
        byte[] byteArray = stream.toByteArray();
        return byteArray;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == 888){
            if (grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                //gallery intent
                Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
                galleryIntent.setType("image/*");
                startActivityForResult(galleryIntent, 888);
            }
            else {
                Toast.makeText(this, "Don't have permission to access file location", Toast.LENGTH_SHORT).show();
            }
            return;
        }
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Intent intent;
        intent = new Intent(Intent.ACTION_GET_CONTENT);

        if (requestCode == 888 && resultCode == RESULT_OK){
            Uri imageUri = data.getData();
            final int takeFlags = intent.getFlags()
                    & (Intent.FLAG_GRANT_READ_URI_PERMISSION
                    | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
// Check for the freshest data.
            getContentResolver().takePersistableUriPermission(imageUri, takeFlags);
            CropImage.activity(imageUri)
                    .setGuidelines(CropImageView.Guidelines.ON) //enable image guidlines
                    .setAspectRatio(1,1)// image will be square
                    .start(this);
        }
        if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE){
            CropImage.ActivityResult result =CropImage.getActivityResult(data);
            if (resultCode == RESULT_OK){
                Uri resultUri = result.getUri();
                //set image choosed from gallery to image view
                imageViewIcon.setImageURI(resultUri);
            }
            else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE){
                Exception error = result.getError();
            }
        }

        super.onActivityResult(requestCode, resultCode, data);
    }
}

Answer 1

下面的演示会将图像存储在数据库中或应用程序的内部存储中。

如果图像大小小于256k（根据public static final int MAX_IMAGESIZETOSTORE = 1024 * 256;），它将存储在数据库中，并可从数据库中检索。

如果图像大于或等于256k（根据public static final int MAXIMAGEBUFFER = 1024 * 1024 * 16;，演示必须具有16MB的限制），则它将存储在应用程序的Files / myimagestores目录（演示创建的myimagestores目录）中，并且图像的路径存储在数据库中。

演示而不是从照相机中获取图像，而是从资产文件夹中获取图像（演示中使用了5个）。

如果图像不在资源文件夹中，并且没有按照以下匹配名称进行定义，则代码将无法正常工作：

String[] imagesToGet = new String[]{"sample001.jpg","sample002.jpg","sample003.jpg","sample004.jpg","sample005.jpg"};

代码

SQLiteHelper.java

基本上，这是您的帮手，具有经过修改的 insertData 方法

：-

public long insertData(String name, String stok, String jual, byte[] image) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues cv = new ContentValues(); cv.put(RECORD_COL_NAME,name); cv.put(RECORD_COL_STOK,stok); cv.put(RECORD_COL_JUAL,jual); if (image.length > 0 && image.length < MAX_IMAGESIZETOSTORE) { cv.put(RECORD_COL_IMAGE,image); } else { cv.put(RECORD_COL_IMAGEPATH,StoreImage.storeImage(mContext,image,name)); } return db.insert(TBLNAME_RECORD,null,cv); }

在类级别声明以下常量：-

public static final int MAX_IMAGESIZETOSTORE = 1024 * 256; public static final String DBNAME = "mydb"; public static final int DBVERSION = 1; public static final String TBLNAME_RECORD = "record"; public static final String RECORD_COl_ID = BaseColumns._ID; public static final String RECORD_COL_NAME = "name"; public static final String RECORD_COL_STOK = "stok"; public static final String RECORD_COL_JUAL = "jual"; public static final String RECORD_COL_IMAGE = "image"; public static final String RECORD_COL_IMAGEPATH = "imagepath";

可以看到另外一列，添加了 imagepath 来存储图像的路径（如果图像存储在数据库中，则为null；反之亦然，如果未存储图像，则为null在数据库中，但图片列为文件）。

StoreImage.java是

：-

public class StoreImage { public static final String IMAGESTOREDIRECTORY = "myimagestore"; public static String storeImage(Context context, byte[] image, String imagename) { File mFilesDirectory = context.getFilesDir(); File mImageStoreDirectory = new File(mFilesDirectory.getPath() + File.separator + IMAGESTOREDIRECTORY); if (!mImageStoreDirectory.exists()) { mImageStoreDirectory.mkdirs(); } File mImageStore = new File(mImageStoreDirectory.getPath() + File.separator + imagename); OutputStream os; try { os = new FileOutputStream(mImageStore); os.write(image); os.flush(); os.close(); } catch (IOException e) { e.printStackTrace(); } return mImageStore.getPath(); } }

从上面可以看到， StoreImage 类的 storeImage 方法存储图像（（传递给 insertData 的byte [] SQliteHelper 类的方法。

也可以看到，上面将在需要时创建 myimagestore 目录。

MainActivity.java是

：-

public class MainActivity extends AppCompatActivity { public static final int MAXIMAGEBUFFER = 1024 * 1024 * 16; SQLiteHelper mDBHlpr; // The demo images copied into the assets folder String[] imagesToGet = new String[]{"sample001.jpg","sample002.jpg","sample003.jpg","sample004.jpg","sample005.jpg"}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mDBHlpr = new SQLiteHelper(this); for (String s: imagesToGet) { mDBHlpr.insertData(s,"stock for " + s,"jual for " + s,getImage(s)); } Cursor csr = mDBHlpr.getData("SELECT * FROM RECORD;"); DatabaseUtils.dumpCursor(csr); csr.close(); } //Get a demo image from the assets folder private byte[] getImage(String name) { byte[] buffer = new byte[0]; try { AssetFileDescriptor afd = this.getAssets().openFd(name); long fsz = afd.getLength(); if (fsz < MAXIMAGEBUFFER) { InputStream is = this.getAssets().open(name); buffer = new byte[(int) fsz]; is.read(buffer, 0, (int) fsz); } } catch (IOException e) { e.printStackTrace(); } return buffer; } }

getImage 方法（大部分活动）从资产文件夹中检索图像（演示图像）。

5个演示图像进行循环处理，并通过 insertData 方法添加到数据库中。

插入后，所有数据都提取到游标中，然后将游标转储（写入日志）。

示例运行：-

根据：-
将图像复制到资源文件夹中

然后运行该应用，然后日志包含：-

06-01 08:59:14.828 7728-7728/? I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@cd7f7ce 06-01 08:59:14.828 7728-7728/? I/System.out: 0 { 06-01 08:59:14.828 7728-7728/? I/System.out: _id=1 06-01 08:59:14.828 7728-7728/? I/System.out: name=sample001.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: stok=stock for sample001.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: jual=jual for sample001.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: image=null 06-01 08:59:14.828 7728-7728/? I/System.out: imagepath=/data/user/0/s.e.so56392635storeimage/files/myimagestore/sample001.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: } 06-01 08:59:14.828 7728-7728/? I/System.out: 1 { 06-01 08:59:14.828 7728-7728/? I/System.out: _id=2 06-01 08:59:14.828 7728-7728/? I/System.out: name=sample002.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: stok=stock for sample002.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: jual=jual for sample002.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: image=null 06-01 08:59:14.828 7728-7728/? I/System.out: imagepath=/data/user/0/s.e.so56392635storeimage/files/myimagestore/sample002.jpg 06-01 08:59:14.828 7728-7728/? I/System.out: } 06-01 08:59:14.829 7728-7728/? I/System.out: 2 { 06-01 08:59:14.829 7728-7728/? I/System.out: _id=3 06-01 08:59:14.829 7728-7728/? I/System.out: name=sample003.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: stok=stock for sample003.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: jual=jual for sample003.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: image=null 06-01 08:59:14.829 7728-7728/? I/System.out: imagepath=/data/user/0/s.e.so56392635storeimage/files/myimagestore/sample003.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: } 06-01 08:59:14.829 7728-7728/? I/System.out: 3 { 06-01 08:59:14.829 7728-7728/? I/System.out: _id=4 06-01 08:59:14.829 7728-7728/? I/System.out: name=sample004.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: stok=stock for sample004.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: jual=jual for sample004.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: image=<unprintable> 06-01 08:59:14.829 7728-7728/? I/System.out: imagepath=null 06-01 08:59:14.829 7728-7728/? I/System.out: } 06-01 08:59:14.829 7728-7728/? I/System.out: 4 { 06-01 08:59:14.829 7728-7728/? I/System.out: _id=5 06-01 08:59:14.829 7728-7728/? I/System.out: name=sample005.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: stok=stock for sample005.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: jual=jual for sample005.jpg 06-01 08:59:14.829 7728-7728/? I/System.out: image=<unprintable> 06-01 08:59:14.829 7728-7728/? I/System.out: imagepath=null 06-01 08:59:14.829 7728-7728/? I/System.out: } 06-01 08:59:14.829 7728-7728/? I/System.out: <<<<<

这表示sample001.jpg-sample003.jpg已存储为文件，例如sample001.jpg（就数据库而言）存储在 /data/user/0/s.e.so56392635storeimage/files/myimagestore/sample001.jpg

显然，软件包名称将与所使用的软件包相同，有时您可能会看到 /data/data/the_package_name/files/myimagestore/sample001.jpg

对于这3张图片，图片列也是空。

对于其他两个（较小）图像，图像列为不可打印（即BLOB），而图像路径列为空。

除了上述测试/检查以下两个屏幕截图外，请确认是否已存储较大的照片。

首先显示资产文件夹中每个资产文件夹的文件大小的资产：-

第二个应用程序的内部存储（数据/数据/）：-

sample004.jpg 和 sample005.jpg 不会出现，因为它们已存储在数据库中。

最后一个证据是已存储了较小的图像，然后对查询进行了简单的修改，按照：-

Cursor csr = mDBHlpr.getData("SELECT *, length(" + SQLiteHelper.RECORD_COL_IMAGE + ") FROM RECORD;");

结果：-

06-01 09:16:36.282 I/System.out: _id=4 06-01 09:16:36.282 I/System.out: name=sample004.jpg 06-01 09:16:36.282 I/System.out: stok=stock for sample004.jpg 06-01 09:16:36.282 I/System.out: jual=jual for sample004.jpg 06-01 09:16:36.282 I/System.out: image=<unprintable> 06-01 09:16:36.282 I/System.out: imagepath=null 06-01 09:16:36.282 I/System.out: length(image)=9000 <<<<<<<<<<<< 06-01 09:16:36.283 I/System.out: } 06-01 09:16:36.283 I/System.out: 4 { 06-01 09:16:36.283 I/System.out: _id=5 06-01 09:16:36.283 I/System.out: name=sample005.jpg 06-01 09:16:36.283 I/System.out: stok=stock for sample005.jpg 06-01 09:16:36.283 I/System.out: jual=jual for sample005.jpg 06-01 09:16:36.283 I/System.out: image=<unprintable> 06-01 09:16:36.283 I/System.out: imagepath=null 06-01 09:16:36.283 I/System.out: length(image)=28239 <<<<<<<<<<<<

其他SQliteHelper.java

这是完整的SQLiteHelper.java：-

public class SQLiteHelper extends SQLiteOpenHelper { public static final int MAX_IMAGESIZETOSTORE = 1024 * 256; public static final String DBNAME = "mydb"; public static final int DBVERSION = 1; public static final String TBLNAME_RECORD = "record"; public static final String RECORD_COl_ID = BaseColumns._ID; public static final String RECORD_COL_NAME = "name"; public static final String RECORD_COL_STOK = "stok"; public static final String RECORD_COL_JUAL = "jual"; public static final String RECORD_COL_IMAGE = "image"; public static final String RECORD_COL_IMAGEPATH = "imagepath"; Context mContext; //constructor <<<<<<<<<< MODIFIED so just requires Context //!!!!!!!!!!NOTE!!!!!!!!!! uses database/tables as defined in this class public SQLiteHelper(Context context){ super(context,DBNAME, null, DBVERSION); mContext = context; } public void queryData(String sql){ SQLiteDatabase database = getWritableDatabase(); database.execSQL(sql); } public long insertData(String name, String stok, String jual, byte[] image) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues cv = new ContentValues(); cv.put(RECORD_COL_NAME,name); cv.put(RECORD_COL_STOK,stok); cv.put(RECORD_COL_JUAL,jual); if (image.length > 0 && image.length < MAX_IMAGESIZETOSTORE) { cv.put(RECORD_COL_IMAGE,image); } else { cv.put(RECORD_COL_IMAGEPATH,StoreImage.storeImage(mContext,image,name)); } return db.insert(TBLNAME_RECORD,null,cv); } //insertData /** public void insertData(String name, String stok, String jual, byte[] image){ SQLiteDatabase database = getWritableDatabase(); //query to insert record in database table String sql = "INSERT INTO RECORD VALUES(NULL, ?, ?, ?, ?)"; //where "RECORD" is table name in database we will create in mainActivity SQLiteStatement statement = database.compileStatement(sql); statement.clearBindings(); statement.bindString(1, name); statement.bindString(2, stok); statement.bindString(3, jual); statement.bindBlob(4, image); statement.executeInsert(); } **/ //updateData public void updateData(String name, String stok, String jual, byte[] image, int id){ SQLiteDatabase database = getWritableDatabase(); //query to update record String sql = "UPDATE RECORD SET name=?, stok=?, jual=?, image=? WHERE id=?"; SQLiteStatement statement = database.compileStatement(sql); statement.bindString(1, name); statement.bindString(2, stok); statement.bindString(3, jual); statement.bindBlob(4, image); statement.bindDouble(5, (double)id); statement.execute(); database.close(); } //deleteData public void deleteData(int id){ SQLiteDatabase database = getWritableDatabase(); //query to delete record using id String sql = "DELETE FROM RECORD WHERE id=?"; SQLiteStatement statement = database.compileStatement(sql); statement.clearBindings(); statement.bindDouble(1, (double)id); statement.execute(); database.close(); } public Cursor getData(String sql){ SQLiteDatabase database = getReadableDatabase(); return database.rawQuery(sql, null); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE IF NOT EXISTS " + TBLNAME_RECORD + "(" + RECORD_COl_ID + " INTEGER PRIMARY KEY," + RECORD_COL_NAME + " TEXT," + RECORD_COL_STOK + " TEXT," + RECORD_COL_JUAL + " TEXT," + RECORD_COL_IMAGE + " BLOB," + RECORD_COL_IMAGEPATH + " TEXT" + ")" ); } @Override public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) { } }

在数据库中另外存储图像

选择256k限制是一个合理的大小，以不将图像存储在DB中。我猜想当您说 2MB下载限制时，您的意思是您遇到的CursorWindow限制为2MB，因此需要存储图像路径。

即使256k也可能太大，因为每个CursorWindow可能导致7行。因此可能会出现问题。但是，考虑到SQlite - 35% Faster Than The Filesystem的发现，那么在100k时，最好将图像存储在数据库中。 这样的实验可能会确定更好的限制。

我需要帮助将图像存储在内部目录中，并且其路径已插入SQLite

1 个答案:

代码

SQLiteHelper.java

StoreImage.java是

MainActivity.java是

示例运行：-

其他SQliteHelper.java

在数据库中另外存储图像