title: How to implement bootstrap (resampling) in Java efficiently
body: <p>I have a data file of 50,000,000 lines and need to bootstrap each line using Java. 
  Right now I am using Math.random() to generate random number, then do the bootstrapping in a brute force way. However, it will take me forever. So i am wondering if there is any Java library help to do this efficiently or should i call other languages inside Java? Anyway my goal is to optimize the whole process. Thank you!</p>