Generating Random Numbers
The java.util.Random class provides a pseudorandom number generator that is more flexible than the one in the Math class. Actually, the random number generator in the Math class just uses one of the methods in the Random class to produce its results. Because the methods in the Random class are not static, you must create an instance of Random to use it. You can do this with the no-argument constructor or the one that accepts a seed:
public Random() public Random(long seed)
"Random" numbers generated by a mathematical algorithm are not truly random, but are instead well-distributed values taken from a sequence that is defined by the algorithm. This distinction is why java.util.Random is described as a pseudorandom ...