How to encode/convert the blob audio file to wav format?

We are using struts2 application where in we have recorded the audio using getUserMedia method in javascript. It produces the audio as a blob file. Now, I want to convert the raw blob file into wav or any other audio format. We are developing in firefox browser.

I need to convert the blob file once mediaStream.stop() is issued.(ie) when the recording stops. Shall I send the blob file to java action class and then convert into wav format or Is there any idea of converting blob to wav in javascript? Kindly, suggest an appropriate method.

Note: recorder.js and recorderWorker.js are not working in firefox.