Setting JVM Heap size at runtime

To set the JVM heap size, compile the program normally.
For example, consider Runtime.java program.

Compilation: javac Runtime.java

Now, to set minimum heap size(let, 16 MB) required by JVM, run the program as follows :

java -Xms16m Runtime 

We can also restrict maximum size(let 512 MB) utilized by JVM:

java -Xmx512m Runtime

 Both these options can also be combined to specify upper and lower bounds of JVM heap size:

java -Xms16m -Xmx512m Runtime

Now you can run a program that requires huge computational space.