android 接收服务端 oracle数据中存储的blob对象 转化为图像

服务端比较好处理：

直接返回一个String类型

return Base64.encode(rs.getBytes("BLOB字段名"));

其中，rs为resultSet,接收查询语句的结果

客户端：

byte[] b = Base64.decode(ru,Base64.DEFAULT);
Bitmap bitmap = BitMapUtil.getBitmapFromByte(b);
if(bitmap!=null)
 {
    setBigBitmap(bitmap);
  }

 

 其中，ru为服务端返回的字符串

BitMapUtil.java:

public class BitMapUtil {
    /**
     * 根据本地图片的path获得Bitmap
     * @param url
     * @return
     */
    public static Bitmap getBitmapFromByte(byte[] b) {
        try {
             BitmapFactory.Options opts = new BitmapFactory.Options();
             /**
              * ALPHA_8：每个像素占用 1byte 内存、
              * ARGB_4444:每个像素占用 2byte 内存、
              * ARGB_8888:每个像素占用 4byte 内存、
              * RGB_565:每个像素占用 2byte 内存。
              * Android默认的颜色模式为ARGB_8888
              */
             opts.inPreferredConfig = Bitmap.Config.RGB_565;//
             opts.inPurgeable = true;  
             opts.inInputShareable = true; 
             opts.inJustDecodeBounds = true;
             BitmapFactory.decodeByteArray(b, 0, b.length, opts);
             opts.inSampleSize = computeSampleSize(opts, -1, 1024*1024);
             opts.inJustDecodeBounds = false;
             Bitmap bmp = BitmapFactory.decodeByteArray(b, 0, b.length, opts);
             return bmp;
        } catch (Exception e) {
             e.printStackTrace();
             return null;
        }
    }
    /**
     * 计算 bitmap 尺寸
     * @param options
     * @param minSideLength
     * @param maxNumOfPixels
     * @return
     */
    private static int computeSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength,
                maxNumOfPixels);
        int roundedSize;
        if (initialSize <= 8) {
            roundedSize = 1;
            while (roundedSize < initialSize) {
                roundedSize <<= 1;
            }
        } else {
            roundedSize = (initialSize + 7) / 8 * 8;
        }
        return roundedSize;
    }

    /**
     * 计算 bitmap 尺寸
     * @param options
     * @param minSideLength
     * @param maxNumOfPixels
     * @return
     */
    private static int computeInitialSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        double w = options.outWidth;
        double h = options.outHeight;
        int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math
                .sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(Math
                .floor(w / minSideLength), Math.floor(h / minSideLength));
        if (upperBound < lowerBound) {
            return lowerBound;
        }
        if ((maxNumOfPixels == -1) && (minSideLength == -1)) {
            return 1;
        } else if (minSideLength == -1) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
}

 

setBigBitmap(Bitmap bitmap)

    public void setBigBitmap(Bitmap bigBitmap) {
        this.bigBitmap = bigBitmap;
        if(cWidth!=0&&cHeight!=0)
        {
            this.setImageBitmap(Bitmap.createScaledBitmap(bigBitmap, cWidth,cHeight, false));
            
        }
        else
        {
            this.setImageBitmap(Bitmap.createScaledBitmap(bigBitmap, this.getWidth(), this.getHeight(), false));
        }
    }

setBigBitmap(Bitmap bitmap)方法是位于一个继承ImageView的类中

这样，这个功能就完成了，需要的时候写个LinearLayout ,add上去就可以了