Answers for "how to get a run time of a function in java"

java execution time

long start = System.currentTimeMillis();
class.method();
long time = System.currentTimeMillis() - start;

running time of java program

long startTime = System.nanoTime();
.....your program....
long endTime   = System.nanoTime();
long totalTime = endTime - startTime;
System.out.println(totalTime);