MongoDB text index for all fields using Java

I want to create a text index for all my fields in MongoDB. I know it can be done like this:

db.collection.ensureIndex({ "$**": "text" },{ name: "TextIndex" })

But I want to create this index in my Java program. I've tried with this:

collection.createIndex(new BasicDBObject("$**","text"),newBasicDBObject("name","TextIndex"));

but it gave me this error: com.mongodb.MongoException: Can't canonicalize query: BadValue unknown operator: $**

I do not know what to do. I see others have asked a similar question, but no one has answered. Can any of you help me?

Thanks in advance.