如何在数据库中插入字节数组？

Question

我在插入android数据库的byte []时遇到问题。 我有两个名为DB.java和DBAdapter.java的类，如下所示。 我收到以下错误。 “错误插入图像= [B @ 43d1b7b8””基本上，我在进行某些操作时仍然无法使用。 希望有人能帮忙。

DB.java：

public class DB extends Activity{
    private final String imageInSD = "/sdcard/e5.jpg";
    Bitmap bitmap;
    byte[] buf =null;

/** Called when the activity is first created. */
@Override
public void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    DBAdapter db = new DBAdapter(this);

    BitmapFactory.Options BitmapFactoryOptionsbfo = new BitmapFactory.Options();
    BitmapFactoryOptionsbfo.inPreferredConfig = Bitmap.Config.RGB_565; 
    bitmap = BitmapFactory.decodeFile(imageInSD, BitmapFactoryOptionsbfo);

    ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos );
        buf = bos.toByteArray(); 

    db.open();        
    long id;
    id = db.insertTitle(buf);        
    db.close();

    System.out.println("ID:"+id);

}

}

DBAdapter.java

public class DBAdapter 
{
    public static final String KEY_IMAGE = "image";    
    private static final String TAG = "DBAdapter";

    private static final String DATABASE_NAME = "books";
    private static final String DATABASE_TABLE = "photo";
    private static final int DATABASE_VERSION = 1;

    private static final String DATABASE_CREATE =
        "create table photo (image blob not null);";

    private final Context context; 

    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public DBAdapter(Context ctx) 
    {
        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }

    private static class DatabaseHelper extends SQLiteOpenHelper 
    {
        DatabaseHelper(Context context) 
        {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) 
        {
            db.execSQL(DATABASE_CREATE);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, 
        int newVersion) 
        {
            Log.w(TAG, "Upgrading database from version " + oldVersion 
                    + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS titles");
            onCreate(db);
        }
    }    

    //---opens the database---
    public DBAdapter open() throws SQLException 
    {
        db = DBHelper.getWritableDatabase();
        return this;
    }

    //---closes the database---    
    public void close() 
    {
        DBHelper.close();
    }


    public long insertTitle(byte[] buf) 
    {   
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_IMAGE, buf);
        return db.insert(DATABASE_TABLE, null, initialValues);
    }
}

Answer 1

我建议您将图像文件保存在sdcard上，并将其路径保存在数据库中。