android用工具类

http://www.iteye.com/topic/1112871

public class ImageUtil {

    public static InputStream getRequest(String path) throws Exception {
        URL url = new URL(path);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5000);
        if (conn.getResponseCode() == 200){
            return conn.getInputStream();
        }
        return null;
    }

    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
        byte[] buffer = new byte[4096];
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outSteam.write(buffer, 0, len);
        }
        outSteam.close();
        inStream.close();
        return outSteam.toByteArray();
    }
    
    public static Drawable loadImageFromUrl(String url){
        URL m;
        InputStream i = null;
        try {
            m = new URL(url);
            i = (InputStream) m.getContent();
        } catch (MalformedURLException e1) {
            e1.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Drawable d = Drawable.createFromStream(i, "src");
        return d;
    }
    
    public static Drawable getDrawableFromUrl(String url) throws Exception{
         return Drawable.createFromStream(getRequest(url),null);
    }
    
    public static Bitmap getBitmapFromUrl(String url) throws Exception{
        byte[] bytes = getBytesFromUrl(url);
        return byteToBitmap(bytes);
    }
    
    public static Bitmap getRoundBitmapFromUrl(String url,int pixels) throws Exception{
        byte[] bytes = getBytesFromUrl(url);
        Bitmap bitmap = byteToBitmap(bytes);
        return toRoundCorner(bitmap, pixels);
    }
    
    public static Drawable geRoundDrawableFromUrl(String url,int pixels) throws Exception{
        byte[] bytes = getBytesFromUrl(url);
        BitmapDrawable bitmapDrawable = (BitmapDrawable)byteToDrawable(bytes);
        return toRoundCorner(bitmapDrawable, pixels);
    }
    
    public static byte[] getBytesFromUrl(String url) throws Exception{
         return readInputStream(getRequest(url));
    }
    
    public static Bitmap byteToBitmap(byte[] byteArray){
        if(byteArray.length!=0){
            return BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
        }
        else {
            return null;
        }  
    }
    
    public static Drawable byteToDrawable(byte[] byteArray){
        ByteArrayInputStream ins = new ByteArrayInputStream(byteArray);
        return Drawable.createFromStream(ins, null);
    }
    
    public static byte[] Bitmap2Bytes(Bitmap bm){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
        return baos.toByteArray();
    }
    
    public static Bitmap drawableToBitmap(Drawable drawable) {

        Bitmap bitmap = Bitmap
                .createBitmap(
                        drawable.getIntrinsicWidth(),
                        drawable.getIntrinsicHeight(),
                        drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                : Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
                drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
    }
    
         /**
          * 图片去色,返回灰度图片
          * @param bmpOriginal 传入的图片
         * @return 去色后的图片
         */
        public static Bitmap toGrayscale(Bitmap bmpOriginal) {
            int width, height;
            height = bmpOriginal.getHeight();
            width = bmpOriginal.getWidth();    
    
            Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
            Canvas c = new Canvas(bmpGrayscale);
            Paint paint = new Paint();
            ColorMatrix cm = new ColorMatrix();
            cm.setSaturation(0);
            ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
            paint.setColorFilter(f);
            c.drawBitmap(bmpOriginal, 0, 0, paint);
            return bmpGrayscale;
        }
        
        
        /**
         * 去色同时加圆角
         * @param bmpOriginal 原图
         * @param pixels 圆角弧度
         * @return 修改后的图片
         */
        public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels) {
            return toRoundCorner(toGrayscale(bmpOriginal), pixels);
        }
        
        /**
         * 把图片变成圆角
         * @param bitmap 需要修改的图片
         * @param pixels 圆角的弧度
         * @return 圆角图片
         */
        public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {
    
            Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);
            Canvas canvas = new Canvas(output);
    
            final int color = 0xff424242;
            final Paint paint = new Paint();
            final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
            final RectF rectF = new RectF(rect);
            final float roundPx = pixels;
    
            paint.setAntiAlias(true);
            canvas.drawARGB(0, 0, 0, 0);
            paint.setColor(color);
            canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
    
            paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
            canvas.drawBitmap(bitmap, rect, rect, paint);
    
            return output;
        }
    
        
       /**
         * 使圆角功能支持BitampDrawable
         * @param bitmapDrawable
         * @param pixels
         * @return
         */
        public static BitmapDrawable toRoundCorner(BitmapDrawable bitmapDrawable, int pixels) {
            Bitmap bitmap = bitmapDrawable.getBitmap();
            bitmapDrawable = new BitmapDrawable(toRoundCorner(bitmap, pixels));
            return bitmapDrawable;
        }
    
}