Can a livy client upload and run different jar packages multiple times?

[adley]

Hi：
    I followed the official example-PiApp.java, and tried to submit and run 
successfully. 
    Then I modified the code and called client.uploadJar (newjar) again after 
client.submit, and finally called the class implementation in newjar, 
client.submit ( newjar-newclass), the upload is successful, no error is 
reported, but it has no effect. The execution result shows that the class 
implementation in oldjar is still called. 
    Can Livy support the repeated submission of jar packages under one client?