The Java Developers Almanac 1.4

e55. Getting the Size of the Java Memory Heap

    // Get current size of heap in bytes
    long heapSize = Runtime.getRuntime().totalMemory();
    
    // Get maximum size of heap in bytes. The heap cannot grow beyond this size.
    // Any attempt will result in an OutOfMemoryException.
    long heapMaxSize = Runtime.getRuntime().maxMemory();
    
    // Get amount of free memory within the heap in bytes. This size will increase
    // after garbage collection and decrease as new objects are created.
    long heapFreeSize = Runtime.getRuntime().freeMemory();

Related Examples

e48. The Quintessential Java Application
e49. Terminating the Application
e50. Determining When the Application Is About to Exit
e51. Computing Elapsed Time
e52. Loading Native Code
e53. Implementing a Class That Can Be Sorted
e54. Redirecting Standard Output, and Error

See also: Arrays    Assertions    Classes    Commands    Numbers    Objects    Strings    System Properties    Threads

© 2002 Addison-Wesley.