Я считаю, что лучший способ сохранить изображение в базе данных SQLLite - это использовать алгоритм Base 64.который преобразует изображение в простой текст и обратно.Вы можете скачать полный пример проекта Android по адресу: http://developersfound.com/Base64FromStream.zip. Эта программа не сохраняет изображение, но конвертирует изображение из изображения в текст и обратно.
Вот класс:
package com.example.TestProject;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Base64;
import android.util.Log;
import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.nio.channels.FileChannel;
public class Base64CODEC {
private int IO_BUFFER_SIZE = 64;
//private int IO_BUFFER_SIZE = 8192;
private URL urlObject = null;
private URLConnection myConn = null;
ByteArrayOutputStream os = null;
public void Base64CODEC() {}
public Bitmap Base64ImageFromURL(String url) {
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
urlObject = new URL(url);
myConn = urlObject.openConnection();
in = myConn.getInputStream();
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copyCompletely(in, out);
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);
} catch (IOException e) {
Log.e("TAG", "Could not load Bitmap from: " + url);
} finally {
//closeStream(in);
try {
in.close();
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
//closeStream(out);
try {
out.close();
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
return bitmap;
}
private void copyCompletely(InputStream input, OutputStream output) throws IOException {
// if both are file streams, use channel IO
if ((output instanceof FileOutputStream) && (input instanceof FileInputStream)) {
try {
FileChannel target = ((FileOutputStream) output).getChannel();
FileChannel source = ((FileInputStream) input).getChannel();
source.transferTo(0, Integer.MAX_VALUE, target);
source.close();
target.close();
return;
} catch (Exception e) { /* failover to byte stream version */
}
}
byte[] buf = new byte[8192];
while (true) {
int length = input.read(buf);
if (length < 0)
break;
output.write(buf, 0, length);
}
try {
input.close();
} catch (IOException ignore) {
}
try {
output.close();
} catch (IOException ignore) {}
}
public String convertToBase64(Bitmap bitmap) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG,100,os);
byte[] byteArray = os.toByteArray();
return Base64.encodeToString(byteArray, 0);
}
public Bitmap convertToBitmap(String base64String) {
byte[] decodedString = Base64.decode(base64String, Base64.DEFAULT);
Bitmap bitmapResult = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
return bitmapResult;
}
}
А вот основной вид деятельности, который использует класс:
package com.example.TestProject;
import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.ImageView;
public class MainActivity extends Activity implements Runnable {
private Thread thread = null;
private Bitmap bitmap = null;
private Base64CODEC base64CODEC = null;
private ImageView imgViewSource = null;
private ImageView imgViewDestination = null;
private boolean isSourceImageVisible = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void CmdLoadImage_Click(View view) {
try {
if(isSourceImageVisible == true) {
imgViewSource.setImageBitmap(null);
imgViewDestination.setImageBitmap(null);
isSourceImageVisible = false;
}
else {
base64CODEC = new Base64CODEC();
thread = new Thread(this);
thread.start();
}
}
catch (NullPointerException e) {}
}
public void CmdEncodeImage_Click(View view) {
Base64CODEC base64CODEC = new Base64CODEC();
try {
String base64String = base64CODEC.convertToBase64(bitmap);
imgViewDestination = (ImageView) findViewById(R.id.imgViewDestination);
Bitmap imgViewDestinationBitmap = base64CODEC.convertToBitmap(base64String);
imgViewDestination.setImageBitmap(imgViewDestinationBitmap);
}
catch (NullPointerException e) {
//
}
}
@Override
public void run() {
bitmap = base64CODEC.Base64ImageFromURL("http://developersfound.com/me.png");
handler.sendEmptyMessage(0);
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
imgViewSource = (ImageView) findViewById(R.id.imgViewSource);
imgViewSource.setImageBitmap(bitmap);
isSourceImageVisible = true;
thread = null;
}
};
}