图片压缩上传

市场上手机像素普遍比较高，拍的相片较大，上传原始图片到服务器耗时耗流量，所以要对图片进行压缩后再进行上传具体流程如下

1、通过文件路径获取图片转化为bitmap对象

 /**     * 通过路径转为bitMap对象     * @param imgPath     * @return     */    public static Bitmap getBitmap(String imgPath) {        final BitmapFactory.Options options = new BitmapFactory.Options();        options.inJustDecodeBounds = true;//只解析图片边沿，获取宽高        BitmapFactory.decodeFile(imgPath, options);        // 计算缩放比 转为320*480大小图片        options.inSampleSize = calculateInSampleSize(options, 320, 480);        // 完整解析图片返回bitmap        options.inJustDecodeBounds = false;        return BitmapFactory.decodeFile(imgPath, options);    }

计算图片大小的方法

 /**     * 计算图片大小     * @param options     * @param reqWidth     * @param reqHeight     * @return     */    public static int calculateInSampleSize(BitmapFactory.Options options,                                            int reqWidth, int reqHeight) {        final int height = options.outHeight;        final int width = options.outWidth;        int inSampleSize = 1;        if (height > reqHeight || width > reqWidth) {            final int heightRatio = Math.round((float) height / (float) reqHeight);            final int widthRatio = Math.round((float) width / (float) reqWidth);            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;        }        return inSampleSize;    }

2、开启线程对图片进行压缩

 /**     * 压缩文件     * @param bmp     * @param file     */    public static void compressBmpToFile(final Bitmap bmp, final File file){        //开启子线程进行压缩        new Thread(new Runnable() {            @Override            public void run() {                ByteArrayOutputStream baos = new ByteArrayOutputStream();                int options = 60;                bmp.compress(Bitmap.CompressFormat.JPEG, options, baos);                //压缩至100k以内                while (baos.toByteArray().length / 1024 > 100) {                    baos.reset();                    options -= 10;                    bmp.compress(Bitmap.CompressFormat.JPEG, options, baos);                }                try {                    FileOutputStream fos = new FileOutputStream(file);                    fos.write(baos.toByteArray());                    fos.flush();                    fos.close();                } catch (Exception e) {                    e.printStackTrace();                }            }        }).start();    }

3、设置压缩图片存储路径

 /**     * 获取sd卡路径     */    public static String getSdcardPath() {        String path = Environment.getExternalStorageDirectory() + File.separator + "edaibu" + File.separator;        File file = new File(path);        if (!file.exists()) {            file.mkdirs();        }        return path;    }

Activity代码中调用返回file类型

 /**     * 压缩图片     * @param imagePath     */    private File compressImg(String imagePath) {        LogUtils.e("压缩前长度："+new File(imagePath).length());        Bitmap bitmap= CompressImageUtil.getBitmap(imagePath);        final String path=CompressImageUtil.getSdcardPath()+index+"compress.jpg";        File files=new File(path);        CompressImageUtil.compressBmpToFile(bitmap,files);        LogUtils.e("压缩后的图片长度："+files.length());        return files;    }

最后记得在图片上传成功后将压缩的图片进行删除

 String compressedPicDir =Environment.getExternalStorageDirectory() + File.separator + "edaibu";        //删除压缩后的图片        destroyPhoto(compressedPicDir);

 /**     * 销毁文件夹图片     */    @TargetApi(Build.VERSION_CODES.KITKAT)    private void destroyPhoto(String path) {        LogUtils.e("销毁拍照图片");        //里面输入特定目录        File file = new File(path);        File temp;        if (file.isDirectory() && file.listFiles().length > 0) {            File[] fileList = file.listFiles();            for (int i = 0; i < fileList.length; i++) {                temp = fileList[i];                temp.delete();            }        }    }