How to fetch BOX application folders and file metadata information using Box Java SDK?

here's a code snippet...

        ...
        BoxAPIConnection api = getBoxAPIConnectionFromState(client_id, client_secret, token, refresh_token, stateConfPath);
        saveBoxAPIConnect(api, stateConfPath);
        listFolder(BoxFolder.getRootFolder(api), 1);
    }

    private static void listFolder(BoxFolder folder, int depth) {
        for (BoxItem.Info itemInfo : folder) {
            String indent = "";
            for (int i = 0; i < depth; i++) {
                indent += "    ";
            }

            System.out.println(indent + itemInfo.getName() + " [" + itemInfo.getID()+ "]");

            if (itemInfo instanceof BoxFile.Info) {
                BoxFile file = (BoxFile)itemInfo.getResource();
                try {
                    Metadata metadata = file.getMetadata();
                    System.out.println(indent + "metadata: " + metadata.toString());
                }
                catch (BoxAPIException ae) {
                    // 404 - you can't do anything about for now
                }
            }
            else if (itemInfo instanceof BoxFolder.Info) {
                BoxFolder childFolder = (BoxFolder) itemInfo.getResource();
                if (depth < 100) {
                    listFolder(childFolder, depth + 1);
                }
            }
        }
    }

and sample output:

Box Reports [removed for privacy7]
        shared_links_run_on_6-8-16__8-**removed**-AM.xlsx [removed for privacy33]
        metadata: {"foo":"bar","$type":"properties","$parent":"file_69084985633","$id":"7b93fbcb-63bb-45**removed**f5a-07b96c2d171f","$version":0,"$typeVersion":2,"$template":"properties","$scope":"global"}

Thanks for reply
I tried your given code using Developer Token to create an API connection :

BoxAPIConnection api = new BoxAPIConnection(DEVELOPER_TOKEN);

 but I'm getting following BoxAPIException :

com.box.sdk.BoxAPIException: The API returned an error code: 404
	at com.box.sdk.BoxAPIResponse.(BoxAPIResponse.java:70)
	at com.box.sdk.BoxJSONResponse.(BoxJSONResponse.java:30)
	at com.box.sdk.BoxAPIRequest.trySend(BoxAPIRequest.java:423)
	at com.box.sdk.BoxAPIRequest.send(BoxAPIRequest.java:209)
	at com.box.sdk.BoxAPIRequest.send(BoxAPIRequest.java:184)
	at com.box.sdk.BoxFile.getMetadata(BoxFile.java:623)
	at com.box.sdk.BoxFile.getMetadata(BoxFile.java:611)

Getting this exception at the time of metadata creation :

Metadata metadata = file.getMetadata();

I think that's why I have it wrapped in a try/catch since "as-user" calls don't work in box-java-sdk.

try {
     Metadata metadata = file.getMetadata();
     System.out.println(indent + "metadata: " + metadata.toString());
}
     catch (BoxAPIException ae) {
     // 404 - you can't do anything about for now
}

"as-user calls don't work in box-java-sdk" I didn't get it can you please elaborate it.

If it does not work in java then there is any another way to fetch BOX folder and file metadata using box-java-sdk?

You'll be able to get your AppUser's content but you won't be able to get another user (managed user's) content.