Android asynchronous image loading method 1 (3)

Utils. Java is as follows:

Package cn. loadImages; import java. io. inputStream; import java. io. outputStream; import android. graphics. bitmap; import android. graphics. bitmapFactory; public class Utils {public static void copyStream (InputStream is, OutputStream OS) {final int buffer_size = 1024; try {byte [] bytes = new byte [buffer_size]; for (;) {int count = is. read (bytes, 0, buffer_size); if (count =-1) {break;} OS. write (bytes, 0, count) ;}} Catch (Exception ex) {}} // obtain the image thumbnail public static Bitmap getBitmapThumbnail (String filePath, int minSideLength, int maxNumOfPixels) {BitmapFactory. options options = new BitmapFactory. options (); // true, the actual bitmap object will not be returned // no memory space is allocated to it, but some decoded boundary information such as the image size can be obtained. options. inJustDecodeBounds = true; // at this time, rawBitmap is nullBitmap rawBitmap = BitmapFactory. decodeFile (filePath, options); if (rawBitmap = null) {System. out. Println ("rawBitmap is null");} // inSampleSize indicates that the thumbnail size is a fraction of the size of the original image, if the value is 3 //, the width and height of the thumbnail are 1/3 of the original image, and the image size is 1/9 of the original size. // calculate sampleSizeint sampleSize = computeSampleSize (options, minSideLength, maxNumOfPixels); // to read an image, you must set options. inJustDecodeBounds sets falseoptions. inJustDecodeBounds = false; options. inSampleSize = sampleSize; // the original image size is 625x690 90.2kB // test the call computeSampleSize (options, 100,200*100); // get sampleSize = 8 // get width and height Bits 79 and 87 // 79*8 = 632 87*8 = 696 Bitmap thumbnailBitmap = BitmapFactory. decodeFile (filePath, options); return thumbnailBitmap;} // reference: // computeSampleSize (BitmapFactory. options options, int minSideLength, int maxNumOfPixels) {int initialSize = computeInitialSampleSize (options, min SideLength, maxNumOfPixels); int roundedSize; if (initialSize <= 8) {roundedSize = 1; while (roundedSize <initialSize) {roundedSize <= 1 ;}} else {roundedSize = (initialSize + 7)/8*8;} return roundedSize;} private static int computeInitialSampleSize (BitmapFactory. options options, int minSideLength, int maxNumOfPixels) {// width of the original image, double w = options. outWidth; // The height of the original image, double h = options. outHeight; int lowe RBound = (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 the larger one when there is no overlapping zone. return lowerBound;} if (maxNumOfPixels =-1) & (minSideLength =-1) {return 1;} else if (minSideLength =-1) {return lowerBound;} else {return upperBound ;}}}