压缩文件的Demo,直接拿来用_文件解压后demo-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_36895346/article/details/78615943

本文详细介绍了在Android平台上如何进行文件压缩的步骤，包括选择合适的压缩库，编写压缩和解压缩的代码示例，以及在实际应用中如何集成和使用这些功能。通过阅读，开发者可以快速掌握在Android应用中实现文件压缩的技能。

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public void compress(String srcPath) {
        DisplayMetrics dm;
        dm = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dm);

        float hh = dm.heightPixels;
        float ww = dm.widthPixels;
        BitmapFactory.Options opts = new BitmapFactory.Options();
        opts.inJustDecodeBounds = true;
        Bitmap bitmap = BitmapFactory.decodeFile(srcPath, opts);
        opts.inJustDecodeBounds = false;
        int w = opts.outWidth;
        int h = opts.outHeight;
        int size = 0;
        if (w <= ww && h <= hh) {
            size = 1;
        } else {
            double scale = w >= h ? w / ww : h / hh;
            double log = Math.log(scale) / Math.log(2);
            double logCeil = Math.ceil(log);
            size = (int) Math.pow(2, logCeil);
        }
        opts.inSampleSize = size;
        bitmap = BitmapFactory.decodeFile(srcPath, opts);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, baos);
        System.out.println(baos.toByteArray().length);
        while (baos.toByteArray().length > 45 * 1024) {
            baos.reset();
            bitmap.compress(Bitmap.CompressFormat.JPEG, quality, baos);
            quality -= 20;
            System.out.println(baos.toByteArray().length);
        }
        try {
            baos.writeTo(new FileOutputStream(srcPath));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                baos.flush();
                baos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }