J2ME in a Nutshell

Name

Runtime

Synopsis

The Runtime class contains methods and variables that provide access to low-level facilities provided by the Java virtual machine. In order to access these facilities, application code must first use the static getRuntime() method to obtain an instance of the Runtime class. The CLDC version of this class contains only a small subset of the functionality of its J2SE counterpart.

The exit() method causes the virtual machine to terminate. A CLDC application is permitted to use this method. However, a MIDlet will receive a SecurityException if it attempts to do so.

The gc() method hints to the garbage collector that it should attempt to reclaim unreferenced memory. Garbage collectors implemented in small-footprint virtual machines (e,g, the KVM) are typically quite agressive at cleaning up unused memory, so the programmer should not have to call this method very often. The totalMemory() method returns the total amount of memory, in bytes, occupied by the Java virtual machine. In some environments, demand for more memory can cause this value to increase as the VM uses extra system resources. The freeMemory() method returns a value that indicates approximately how much of the total memory occupied by the Java VM is free for allocation to new objects.

public class Runtime {
// No Constructor
                    
// Public Class Methods
   public static Runtime getRuntime();    
// Public Instance Methods
   public void exit( int status);  
   public long freeMemory();                                     // native
   public void gc(); ...