và vào những thời điểm khác được gọi bằng tên lớp và tên gói. Nếu tên gói luôn luôn được sử dụng, tóm tắt lớp học sẽ trở nên dài và khó đọc. Mặt khác, nếu tên gói không bao giờ được sử dụng, đôi khi nó sẽ là khó để biết những gì lớp học đã được nhắc đến. Các quy tắc để bao gồm hoặc bỏ sót tên gói rất phức tạp. Họ có thể được tóm tắt gần như sau, tuy nhiên: | J2ME in a Nutshell Runtime CLDC MIDP 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 public void gc public long totalMemory Returned By RuntimeException CLDC MIDP native native native unchecked A base class for Exception subclasses that need not be be declared in the throws clause of a method definition and consequently application code need not catch. Exceptions of this type are generally caused by programming errors and need to be addressed during application development rather than attempting recovery at run time. This class is the same as its J2SE equivalent apart from .
