为什么使用s3（java lib）上传的文件仍然具有内容类型application / octet-stream

Question

为什么使用java s3库上传的文件具有内容类型application / octet-stream 当我从网上访问它时，即使我在上传时将contentEncoding设置为代码中的text / html？

private void setUpClusterer() {
    // Declare a variable for the cluster manager.
    private ClusterManager<MyItem> mClusterManager;

    // Position the map.
    getMap().moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(51.503186, -0.126446), 10));

    // Initialize the manager with the context and the map.
    // (Activity extends context, so we can pass 'this' in the constructor.)
    mClusterManager = new ClusterManager<MyItem>(this, getMap());

    // Point the map's listeners at the listeners implemented by the cluster
    // manager.
    getMap().setOnCameraChangeListener(mClusterManager);
    getMap().setOnMarkerClickListener(mClusterManager);

    // Add cluster items (markers) to the cluster manager.
    addItems();
}

private void addItems() {

    // Set some lat/lng coordinates to start with.
    double lat = 51.5145160;
    double lng = -0.1270060;

    // Add ten cluster items in close proximity, for purposes of this example.
    for (int i = 0; i < 10; i++) {
        double offset = i / 60d;
        lat = lat + offset;
        lng = lng + offset;
        MyItem offsetItem = new MyItem(lat, lng);
        mClusterManager.addItem(offsetItem);
    }
}