如何使用活动的android序列化字节数组并将其存储到数据库中？

Question

I have an image as byte[] and I need to save this image in database. I use Active Android library for this purpose. I know that data type in db for this purpose should be BLOB. I know that byte[] can't be stored directly and I know that it should serialized. But when I try to serialize it - problem arises.

I tried to convert byte[] to String and then isnsert it to database- it worked: I saved it in database. But then, when I get this string back from db and convert it back to array of bytes, this array is not equal to the first one so when I try to decode this array as an image I receive

skia: --- SkImageDecoder::Factory returned null.

My question is: what should I do to serialize byte array, save it into database, deserialize it back to byte array which will be equal to first one? Exactly steps I mean.

I really was searching how to solve this problem for a very long time and I kindly ask you not to share here links to Active Android documentation or examples of TypeSerializer implementation for other classes - I saw that a lot of times. What I need is exactly way how to solve this problem step by step.

EDIT

Present code of my TypeSerializer which give me opportunity to save byte array at database with Active Android

public class ByteArraySerializer extends TypeSerializer {

    @Override
    public Class<?> getDeserializedType() {
        return byte[].class;
    }

    @Override
    public Class<?> getSerializedType() {
        return String.class;
    }

    @Override
    public Object serialize(Object o) {
        if ( o != null ) {
            return  new String((byte[]) o);
        }
        return null;
    }

    @Override
    public Object deserialize(Object o) {
        if ( o != null ) {
            String str = (String) o;
            return str.getBytes();
        }
        return null;
    }
}

Answer 1

I know that byte[] can't be stored directly

Incorrect. A byte[] can be stored directly into a BLOB column.

In JDBC, you'd set it by calling PreparedStatement.setBytes() , and get it by calling ResultSet.getBytes() .

Any functional ORM should support mapping a BLOB column to byte[] fields.

For Active Android, see these links:

• ActiveAndroid Not saving blob type data(Image) in Sqlite
• http://stackrun.info/qs?id=is35529638

You may have to serialize byte[] to a java.sql.Blob .