how to store Image as blob in Sqlite & how to retrieve it?

后端 未结 6 939
野的像风
野的像风 2020-11-22 04:31

I want to store an image(from url) into a sqlite database.

For that I use:

db = new DataBase(getApplicationContext());
URL url = new URL(\"http://sr         


        
相关标签:
6条回答
  • 2020-11-22 05:00
    byte[] byteArray = rs.getBytes("columnname");  
    
    Bitmap bm = BitmapFactory.decodeByteArray(byteArray, 0 ,byteArray.length);
    
    0 讨论(0)
  • 2020-11-22 05:01

    in the DBAdaper i.e Data Base helper class declare the table like this

     private static final String USERDETAILS=
        "create table userdetails(usersno integer primary key autoincrement,userid text not null ,username text not null,password text not null,photo BLOB,visibility text not null);";
    

    insert the values like this,

    first convert the images as byte[]

    ByteArrayOutputStream baos = new ByteArrayOutputStream();  
    Bitmap bitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.common)).getBitmap();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);   
    byte[] photo = baos.toByteArray(); 
    db.insertUserDetails(value1,value2, value3, photo,value2);
    

    in DEAdaper class

     public long insertUserDetails(String uname,String userid, String pass, byte[] photo,String visibility) 
    {
        ContentValues initialValues = new ContentValues();
        initialValues.put("username", uname);
        initialValues.put("userid",userid);
        initialValues.put("password", pass);
        initialValues.put("photo",photo);
        initialValues.put("visibility",visibility);
        return db.insert("userdetails", null, initialValues);
    }
    

    retrieve the image as follows

    Cursor cur=your query;
    while(cur.moveToNext())
    {
         byte[] photo=cur.getBlob(index of blob cloumn);
    }
    

    convert the byte[] into image

    ByteArrayInputStream imageStream = new ByteArrayInputStream(photo);
    Bitmap theImage= BitmapFactory.decodeStream(imageStream);
    

    I think this content may solve your problem

    0 讨论(0)
  • 2020-11-22 05:04

    In insert()

    public void insert(String tableImg, Object object,
            ContentValues dataToInsert) {
    
       db.insert(tablename, null, dataToInsert);
    }
    

    Hope it helps you.

    0 讨论(0)
  • 2020-11-22 05:04

    for a ionic project

    
        var imgURI       = "";
        var imgBBDD      = ""; //sqllite for save into
    
        function takepicture() {
                    var options = {
                        quality : 75,
                        destinationType : Camera.DestinationType.DATA_URL,
                        sourceType : Camera.PictureSourceType.CAMERA,
                        allowEdit : true,
                        encodingType: Camera.EncodingType.JPEG,
                        targetWidth: 300,
                        targetHeight: 300,
                        popoverOptions: CameraPopoverOptions,
                        saveToPhotoAlbum: false
                    };
    
                    $cordovaCamera.getPicture(options).then(function(imageData) {
                        imgURI = "data:image/jpeg;base64," + imageData;
                        imgBBDD = imageData;
                    }, function(err) {
                        // An error occured. Show a message to the user
                    });
                }
    
    

    And now we put imgBBDD into SqlLite

    
         function saveImage = function (theId, theimage){
          var insertQuery = "INSERT INTO images(id, image) VALUES("+theId+", '"+theimage+"');"
          console.log('>>>>>>>');
          DDBB.SelectQuery(insertQuery)
                        .then( function(result) {
                            console.log("Image saved");
                        })
                        .catch( function(err) 
                         {
                            deferred.resolve(err);
                            return cb(err);
                        });
        }
    
    

    A server side (php)

    
            $request = file_get_contents("php://input"); // gets the raw data
            $dades = json_decode($request,true); // true for return as array
    
    
        if($dades==""){
                $array = array();
                $array['error'] = -1;
                $array['descError'] = "Error when get the file";
                $array['logError'] = '';
                echo json_encode($array);
                exit;
            }
            //send the image again to the client
            header('Content-Type: image/jpeg');
            echo '';
    
    
    0 讨论(0)
  • 2020-11-22 05:04

    you may also want to encode and decode to/from base64

        function uncompress(str:String):ByteArray {
                import mx.utils.Base64Decoder;
                var dec:Base64Decoder = new Base64Decoder();
                dec.decode(str);
                var newByteArr:ByteArray=dec.toByteArray();        
                return newByteArr;
            }
    
    
        // Compress a ByteArray into a Base64 String.
        function compress(bytes:ByteArray):String { 
            import mx.utils.Base64Decoder; //Transform String in a ByteArray.
            import mx.utils.Base64Encoder; //Transform ByteArray in a readable string.
            var enc:Base64Encoder = new Base64Encoder();    
            enc.encodeBytes(bytes);
            return enc.drain().split("\n").join("");
        }
    
    0 讨论(0)
  • 2020-11-22 05:07

    Here the code i used for my app

    This code will take a image from url and convert is to a byte array

    byte[] logoImage = getLogoImage(IMAGEURL);
    
    private byte[] getLogoImage(String url){
         try {
                 URL imageUrl = new URL(url);
                 URLConnection ucon = imageUrl.openConnection();
    
                 InputStream is = ucon.getInputStream();
                 BufferedInputStream bis = new BufferedInputStream(is);
    
                 ByteArrayBuffer baf = new ByteArrayBuffer(500);
                 int current = 0;
                 while ((current = bis.read()) != -1) {
                      baf.append((byte) current);
                 }
    
                 return baf.toByteArray();
         } catch (Exception e) {
              Log.d("ImageManager", "Error: " + e.toString());
         }
         return null;
    }
    

    To save the image to db i used this code.

     public void insertUser(){
            SQLiteDatabase db = dbHelper.getWritableDatabase();
            String delSql = "DELETE FROM ACCOUNTS";
            SQLiteStatement delStmt = db.compileStatement(delSql);
            delStmt.execute();
    
            String sql = "INSERT INTO ACCOUNTS (account_id,account_name,account_image) VALUES(?,?,?)";
            SQLiteStatement insertStmt = db.compileStatement(sql);
            insertStmt.clearBindings();
            insertStmt.bindString(1, Integer.toString(this.accId));
            insertStmt.bindString(2,this.accName);
            insertStmt.bindBlob(3, this.accImage);
            insertStmt.executeInsert();
            db.close();
    }
    

    To retrieve the image back this is code i used.

    public Account getCurrentAccount() {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        String sql = "SELECT * FROM ACCOUNTS";
        Cursor cursor = db.rawQuery(sql, new String[] {});
    
        if(cursor.moveToFirst()){
            this.accId  = cursor.getInt(0);
            this.accName = cursor.getString(1);
            this.accImage = cursor.getBlob(2);
        }
        if (cursor != null && !cursor.isClosed()) {
            cursor.close();
        }
        db.close();
        if(cursor.getCount() == 0){
            return null;
        } else {
            return this;
        }
    }
    

    Finally to load this image to a imageview

    logoImage.setImageBitmap(BitmapFactory.decodeByteArray( currentAccount.accImage, 
            0,currentAccount.accImage.length));
    
    0 讨论(0)
提交回复
热议问题