AudioFileIO's getTag() fails

Question

I am trying to use org.jaudiotagger.audio.AudioFileIO to read some tags in mp3 files. The following lines work correctly:

fileObj = createObject("java", "java.io.File").init(lsFileNameWithPath);
audioFileIO = createObject("java", "org.jaudiotagger.audio.AudioFileIO");
audioFile = audioFileIO.read(fileObj);
audioHeader = audioFile.getAudioHeader();
bitrate = audioHeader.getBitRate();
writeOutput("The audio file bitrate is: " & bitrate);
writeOutput(AudioHeader);

but If I try anything with tags such as:
Tag tag = audioFile.getTag(); or
lsArtist = audioFile.getTag().getFirst(FieldKey.ARTIST);
I get error messages. In the first case the error message is “ Variable TAG is undefined.“ and in the second case the error message is “ Variable FIELDKEY is undefined”

Any suggestions as to what I am doing wrong?

BKBK · Accepted Answer

As to the question of what you are doing wrong, Charlie has provided a suggestion. Namely that it is incorrect to import Java verbatim into ColdFusion using

Tag tag = audioFile.getTag();

I agree. As he says, cfjava would be handy if you wanted to use Java code directly in ColdFusion to create Java classes.

However, what I want to suggest are ways to ensure that the code you have shown works:

(1) ColdFusion determines type implicitly. So, you can replace the above line with

tag = audioFile.getTag();

(2) On googling org.jaudiotagger.audio I found the Jaudiotagger library on Github. According to this documentation, FieldKey is a class that represents an enumeration. The keys in FieldKey , such as ALBUM, ARTIST, BARCODE, etc., are static constants. Therefore you could replace

lsArtist = audioFile.getTag().getFirst(FieldKey.ARTIST);

with something like

fieldKey = createobject("java","org.jaudiotagger.tag.FieldKey");
// use tag instance created earlier
lsArtist = tag.getFirst(fieldKey.ARTIST);

That’s just a start. Let us know how it goes. We’ll discuss further if and where necessary.

Charlie Arehart · Answer

The two lines in error are Java rather than cfml, which your first 7 lines clearly are. You can't just drop Java into cfml. As your first 7 lines reflect, you can instantiate Java objects and use them--via cfml that refers to the objects.

The first error is that you have "Tag tag". That first reference would (in Java) define the class of the object. Cf doesn't support that. (That's why it's undefined. You could prove that by changing the first to be tag1, and see if the error changes to refer to that.)

The second error is similar: your reference to FieldKey in that second line would be a "field" in Java...and cf against doesn't support that by such a line of cfml. (It is possible to declare and use fields within a Java class. You can find more on that in docs, online, or via AI).

Finally, note that since cf2021 it's been possible to actually use pure Java within cfml, by way of the cfjava tag. Again, you can find more on that if interested.

Let us know how if this helps.

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