android cómo guardar un mapa de bits - código de error

Question

Im intentando serializar una clase en la que tengo una variable de mapa de bits. Aquí está el código que es un poco de trabajo .... Necesito ayuda para averiguar lo que sigue siendo incorrecto .....

private Bitmap myVideoScreenshotBm; 

private void writeObject(ObjectOutputStream out) throws IOException{ 

    out.writeInt(myVideoScreenshotBm.getRowBytes()); 
    out.writeInt(myVideoScreenshotBm.getHeight()); 
    out.writeInt(myVideoScreenshotBm.getWidth()); 

    int bmSize = myVideoScreenshotBm.getHeight() * myVideoScreenshotBm.getRowBytes(); 
    ByteBuffer dst= ByteBuffer.allocate(bmSize); 

    myVideoScreenshotBm.copyPixelsToBuffer(dst); 

    byte[] bytesar=new byte[bmSize]; 
    dst.position(0); 
    dst.get(bytesar); 

    out.write(bytesar); 


} 

private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException{ 

    int nbRowBytes=in.readInt(); 
    int height=in.readInt(); 
    int width=in.readInt(); 
    // 
    int bmSize = nbRowBytes * height; 
    byte[] toread= new byte[bmSize]; 

    in.read(toread, 0, toread.length); 
    ByteBuffer dst= ByteBuffer.allocate(bmSize); 
    dst.put(toread); 
    dst.position(0); 
    myVideoScreenshotBm=Bitmap.createBitmap(width, height, Bitmap.Config.ALPHA_8); 
    myVideoScreenshotBm.copyPixelsFromBuffer(dst); 

} 

no estoy recibiendo un error, pero el mapa de bits Im que consigue son mal ... Además, no sé cómo saber qué indicador de Bitmap.Config es adecuado ... ¿cómo saberlo?

¿Alguna ayuda?

Answer 1

Aquí está el código para una serialización con optimización de memoria. Estoy usando un búfer estático que está creciendo hasta el tamaño de mapa de bits más grande y que reutilizo cada vez.

public class Video implements Serializable{ 
public long videoId; 
public String title; 
public String publisher; 
public String language; 
public Date lastModified; 
public Date published; 
public String imageUrl; 
public String url; 
public Bitmap myVideoScreenshotBm; 
public Date expireTime; 
//public Drawable myVideoScreenshotDrawable; 

private static ByteBuffer dst; 
private static byte[] bytesar; 

public Video (long newVideoId) { 
    this.videoId=newVideoId; 
} 
private void writeObject(ObjectOutputStream out) throws IOException{ 

    out.writeLong(videoId); 

    out.writeObject(title); 
    out.writeObject(publisher); 
    out.writeObject(language); 
    out.writeObject(lastModified); 
    out.writeObject(published); 
    out.writeObject(expireTime); 

    out.writeObject(imageUrl); 
    out.writeObject(url); 


    out.writeInt(myVideoScreenshotBm.getRowBytes()); 
    out.writeInt(myVideoScreenshotBm.getHeight()); 
    out.writeInt(myVideoScreenshotBm.getWidth()); 

    int bmSize = myVideoScreenshotBm.getRowBytes() * myVideoScreenshotBm.getHeight(); 
    if(dst==null || bmSize > dst.capacity()) 
     dst= ByteBuffer.allocate(bmSize); 

    out.writeInt(dst.capacity()); 

    dst.position(0); 

    myVideoScreenshotBm.copyPixelsToBuffer(dst); 
    if(bytesar==null || bmSize > bytesar.length) 
     bytesar=new byte[bmSize]; 

    dst.position(0); 
    dst.get(bytesar); 


    out.write(bytesar, 0, bytesar.length); 

} 

private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException{ 

    videoId=in.readLong(); 

    title=(String) in.readObject(); 
    publisher=(String) in.readObject(); 
    language=(String) in.readObject(); 
    lastModified=(Date) in.readObject(); 
    published=(Date) in.readObject(); 
    expireTime=(Date) in.readObject(); 

    imageUrl = (String) in.readObject(); 
    url = (String) in.readObject(); 


    int nbRowBytes=in.readInt(); 
    int height=in.readInt(); 
    int width=in.readInt(); 

    int bmSize=in.readInt(); 



    if(bytesar==null || bmSize > bytesar.length) 
     bytesar= new byte[bmSize]; 


    int offset=0; 

    while(in.available()>0){ 
     offset=offset + in.read(bytesar, offset, in.available()); 
    } 


    if(dst==null || bmSize > dst.capacity()) 
     dst= ByteBuffer.allocate(bmSize); 
    dst.position(0); 
    dst.put(bytesar); 
    dst.position(0); 
    myVideoScreenshotBm=Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
    myVideoScreenshotBm.copyPixelsFromBuffer(dst); 
    //in.close(); 
} 

}

Answer 2

No hay necesidad de tener la matriz redundante + toda la lógica alrededor de + usar los métodos dados para manipular la memoria intermedia + UTF es mejor para cuerdas y evitar los elencos + sincronización (pero no es hilo seguro de todos modos):

private synchronized void writeObject(final ObjectOutputStream out) throws IOException { 
    out.writeUTF(title); 
    out.writeUTF(url_friendly_name); 
    out.writeUTF(creator_name); 
    out.writeUTF(version); 
    out.writeUTF(package_name); 
    out.writeUTF(contact_website); 
    out.writeInt(popularity); 
    out.writeUTF(inconditional_redirect == null ? "" : inconditional_redirect); 
    out.writeUTF(custom_description == null ? "" : custom_description); 

    out.writeInt(icon.getRowBytes()); 
    out.writeInt(icon.getHeight()); 
    out.writeInt(icon.getWidth()); 
    out.writeInt(icon.getConfig().ordinal()); 

    final int bmSize = icon.getRowBytes() * icon.getHeight(); 
    if (dst == null || bmSize > dst.capacity()) { 
     dst = ByteBuffer.allocate(bmSize); 
    } 
    dst.rewind(); 
    icon.copyPixelsToBuffer(dst); 
    dst.flip(); 
    out.write(dst.array(), 0, bmSize); 
} 


private synchronized void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { 
    title = in.readUTF(); 
    url_friendly_name = in.readUTF(); 
    creator_name = in.readUTF(); 
    version = in.readUTF(); 
    package_name = in.readUTF(); 
    contact_website = in.readUTF(); 
    popularity = in.readInt(); 
    inconditional_redirect = in.readUTF(); 
    custom_description = in.readUTF(); 

    final int nbRowBytes = in.readInt(); 
    final int height = in.readInt(); 
    final int width = in.readInt(); 
    final Bitmap.Config config = Bitmap.Config.values()[in.readInt()]; 

    final int bmSize = nbRowBytes * height; 
    if (dst == null || bmSize > dst.capacity()) { 
     dst = ByteBuffer.allocate(bmSize); 
    } 
    dst.rewind(); 
    in.read(dst.array(), 0, bmSize); 

    icon = Bitmap.createBitmap(width, height, config); 
    icon.copyPixelsFromBuffer(dst); 
} 

Answer 3

Para simplificar las cosas, puede utilizar la serialización estándar para todos los campos que no sean el mapa de bits. Simplemente marque el mapa de bits como transitorio y use out.defaultWriteObject(); y in.defaultReadObject() ;. Esto realmente limpia el código:

private String title; 
private String description; 
private transient Bitmap icon; 

private synchronized void writeObject(final ObjectOutputStream out) 
    throws IOException { 
    // Serialize everything but the image 
    out.defaultWriteObject(); 

    // Now serialize the image 
    out.writeInt(icon.getRowBytes()); 
    out.writeInt(icon.getHeight()); 
    out.writeInt(icon.getWidth()); 
    out.writeInt(icon.getConfig().ordinal()); 

    final int bmSize = icon.getRowBytes() * icon.getHeight(); 
    if (dst == null || bmSize > dst.capacity()) { 
    dst = ByteBuffer.allocate(bmSize); 
    } 
    dst.rewind(); 
    icon.copyPixelsToBuffer(dst); 
    dst.flip(); 
    out.write(dst.array(), 0, bmSize); 
} 

private void readObject(ObjectInputStream in) throws IOException, 
    ClassNotFoundException { 
    // Read everything but the image 
    in.defaultReadObject(); 

    // Now read the image 
    final int nbRowBytes = in.readInt(); 
    final int height = in.readInt(); 
    final int width = in.readInt(); 
    final Bitmap.Config config = Bitmap.Config.values()[in.readInt()]; 

    final int bmSize = nbRowBytes * height; 
    if (dst == null || bmSize > dst.capacity()) { 
    dst = ByteBuffer.allocate(bmSize); 
    } 
    dst.rewind(); 
    in.read(dst.array(), 0, bmSize); 

    icon = Bitmap.createBitmap(width, height, config); 
    icon.copyPixelsFromBuffer(dst); 
}