If an application’s behavior is dependent on the amount of available memory, then this code fragment can be used to determine what action an application should take. For example, a text editor may not allow any more files to be opened, when the amount of free memory falls to a tenth of the total available memory.

The code also warns when available memory falls below a certain level, and attempts to free up memory.

 public class MemTester{static long totalMemory;static long freeMemory;public static void main(String[] args) {    Runtime runtime = Runtime.getRuntime();    totalMemory = runtime.totalMemory();    freeMemory = runtime.freeMemory();    if (freeMemory < totalMemory/4 ) {        System.out.println("Running low on memory");        System.out.println("Attempting to free up memory");        System.gc();    }    else       System.out.println("Currently " + freeMemory _+ " bytes are free outof " + totalMemory + " bytes"); }}