Obtaining memory available to JVM at runtime

Question

I\'m trying to sort a bunch of data such that that the size of data input to the program can be larger than the memory available to the JVM, and handling that requires exter

Answer 1

Check out these methods on the java.lang.Runtime class:

freeMemory

totalMemory

maxMemory

Example

Runtime rt = Runtime.getRuntime();
System.err.println(String.format("Free: %d bytes, Total: %d bytes, Max: %d bytes",
  rt.freeMemory(), rt.totalMemory(), rt.maxMemory()));

Also note that if the total amount of memory is being exhausted you can always start the JVM with a larger amount of heap allocated using the -Xmx JVM argument; e.g.

java -Xmx256M MyClass