Java Utililty Methods Memory Used

long calcUsedMemorySize()
calculate used memory size.

return Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();

void disposeUnusedMemory()
Freeing memory that is available for the application by running the garbage collector.

Runtime.getRuntime().gc();

long getAvailableUnusedMemory()
Find out how much unused memory (in bytes) is still available for the JVM to use.

Runtime r = Runtime.getRuntime();
return r.maxMemory() 
 - r.totalMemory() 
 + r.freeMemory(); 

int getMemoryInUse()
Returns the number of megabytes (MB) of memory in use.

Runtime runtime = Runtime.getRuntime();
long mb = 1024 * 1024;
long total = runtime.totalMemory();
long free = runtime.freeMemory();
return (int) ((total - free) / mb);

long getMemoryUse()
retrieve the usage of memory.

putOutTheGarbage();
long totalMemory = Runtime.getRuntime().totalMemory();
putOutTheGarbage();
long freeMemory = Runtime.getRuntime().freeMemory();
return (totalMemory - freeMemory);

long getMemoryUsed()
get Memory Used

return Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();

int getMemoryUsed()
get Memory Used

int mb = 1024 * 1024;
Runtime runtime = Runtime.getRuntime();
int memoryUsed = (int) ((runtime.totalMemory() - runtime.freeMemory()) / mb);
return memoryUsed;

int getMemoryUsed()
Get the used memory in KB.

collectGarbage();
Runtime rt = Runtime.getRuntime();
long mem = rt.totalMemory() - rt.freeMemory();
return (int) (mem >> 10);

long getMemoryUsedBytes()
get Memory Used Bytes

final Runtime runtime = Runtime.getRuntime();
return runtime.totalMemory() - runtime.freeMemory();

String getMemoryUsege()
get Memory Usege

return String.format("memory={total: %d MB, free: %d MB, used: %d MB, max: %d MB}",
 (Runtime.getRuntime().totalMemory() / 1000 / 1000),
 (Runtime.getRuntime().freeMemory() / 1000 / 1000),
 ((Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / 1000 / 1000),
 (Runtime.getRuntime().maxMemory() / 1000 / 1000));