使用Android Intent共享文件：删除文件扩展名

Question

I'm using the following code to share an audio file with Android Studio 3.3.2 and Java. The file is extracted from the /raw/ folder.

public void funktionTeilen(String file) {
    Uri uri = Uri.parse("android.resource://" + this.getPackageName() + "/raw/" + file);
    Intent share = new Intent(Intent.ACTION_SEND);
    share.setType("audio/mpeg3");
    share.putExtra(Intent.EXTRA_STREAM, uri);
    startActivity(Intent.createChooser(share, "Audio teilen"));
}

In principle the sharing works fine, but the file is sent without a file extension, which of course makes it unreadable by most apps. If I add the file extension manually (for example after downloading it from the e-mail client), the MP3 works fine.

"file" is fed in by another function and corresponds to the file name from the raw folder. It is also found basically, otherwise the sharing process would not work at all.

So, how can I share a file with retention of the file extension? Thanks for your help!

Update #1

public void funktionTeilen(String Datei) {


    try {
        File tmpFile = new File(this.getCacheDir() + "/tmpfile.mp3");
        InputStream in = getResources().openRawResource(R.raw.meise1);
        FileOutputStream out = new FileOutputStream(tmpFile, true);
        byte[] buff = new byte[1024];
        int read = 0;

        try {
            while ((read = in.read(buff)) > 0) {
                out.write(buff, 0, read);
            }
        } finally {
            in.close();
            out.close();
        }

        // Uri uri = FileProvider.getUriForFile(this, this.getPackageName(), tmpFile);
        Uri uri = Uri.fromFile(tmpFile);
        Intent share = new Intent(Intent.ACTION_SEND);
        share.setType("audio/*");
        share.putExtra(Intent.EXTRA_STREAM, uri);
        startActivity(Intent.createChooser(share, "Audio teilen"));

    } catch (Exception e) {
        Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
    }

}

Answer 1

I'm using the following code to share an audio file with Android Studio 3.3.2 and Java

You are sharing a resource. That is a file on your development machine. It is not a file on the device.

In principle the sharing works fine, but the file is sent without a file extension, which of course makes it unreadable by most apps.

In Android, resources do not have file extensions when we work with them using the Android SDK.

So, how can I share a file with retention of the file extension?

If you share an actual file , using FileProvider , it will have a file extension. So, copy the bytes corresponding to your resource to a file (eg, in getCacheDir() ), then set up FileProvider and use FileProvider.getUriForFile() to get the Uri to use with EXTRA_STREAM .

Answer 2

I worked out the solution!

MainActivity.java

public void funktionTeilen(String Datei) {

    try {
        File tmpFile = new File(this.getCacheDir() + "/tmpfile.mp3");
        InputStream in = getResources().openRawResource(R.raw.meise1);
        FileOutputStream out = new FileOutputStream(tmpFile, false);
        byte[] buff = new byte[1024];
        int read = 0;

        try {
            while ((read = in.read(buff)) > 0) {
                out.write(buff, 0, read);
            }
        } finally {
            in.close();
            out.close();
            /* if (tmpFile.exists()) {
                Toast.makeText(MainActivity.this, tmpFile.getAbsolutePath(), Toast.LENGTH_LONG).show();
            } */
        }

        Uri uri = FileProvider.getUriForFile(this, BuildConfig.APPLICATION_ID, tmpFile.getAbsoluteFile());
        Intent share = new Intent(Intent.ACTION_SEND);
        share.setType("audio/mpeg3");
        share.putExtra(Intent.EXTRA_STREAM, uri);
        startActivity(Intent.createChooser(share, "Audio teilen"));

    } catch (Exception e) {
        Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
    }

}

AndroidManifest.xml

<application>
        <provider
        android:name="android.support.v4.content.FileProvider"
        android:grantUriPermissions="true"
        android:exported="false"
        android:authorities="${applicationId}">

        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_provider_paths"/>

    </provider>

</application>

file_provider_paths.xml

<paths>
    <cache-path name="cache" path="/" />
    <files-path name="files" path="/" />
</paths>