| java.lang.Object | |
| ↳ | java.lang.Runtime |
Class Overview
Every Java application has a single instance of class Runtime
that allows the application to interface with the environment in which the
application is running. The current runtime can be obtained from the
getRuntime method.
An application cannot create its own instance of this class.
See Also
Summary
| Public Methods | |||||||||||
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| void |
exit(int status)
Terminates the currently running Java application.
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| long |
freeMemory()
Returns the amount of free memory in the system.
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| void |
gc()
Runs the garbage collector.
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| static Runtime |
getRuntime()
Returns the runtime object associated with the current Java application.
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| long |
totalMemory()
Returns the total amount of memory in the Java Virtual Machine.
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
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Public Methods
public void exit (int status)
Terminates the currently running Java application. This method never returns normally.
The argument serves as a status code; by convention, a nonzero status code indicates abnormal termination.
Parameters
| status | exit status. |
|---|
public long freeMemory ()
Returns the amount of free memory in the system. Calling the gc
method may result in increasing the value returned by
freeMemory.
Returns
- an approximation to the total amount of memory currently available for future allocated objects, measured in bytes.
public void gc ()
Runs the garbage collector. Calling this method suggests that the Java Virtual Machine expend effort toward recycling unused objects in order to make the memory they currently occupy available for quick reuse. When control returns from the method call, the Java Virtual Machine has made its best effort to recycle all discarded objects.
The name gc stands for "garbage collector". The Java Virtual
Machine performs this recycling process automatically as needed, in a
separate thread, even if the gc method is not invoked
explicitly.
The method gc() is hte conventional and convenient means of
invoking this method.
public static Runtime getRuntime ()
Returns the runtime object associated with the current Java application. Most
of the methods of class Runtime are instance methods and must be
invoked with respect to the current runtime object.
Returns
- the
Runtimeobject associated with the current Java application.
public long totalMemory ()
Returns the total amount of memory in the Java Virtual Machine. The value returned by this method may vary over time, depending on the host environment.
Note that the amount of memory required to hold an object of any given type may be implementation-dependent.
Returns
- the total amount of memory currently available for current and future objects, measured in bytes.