Runtime (Java Card API, Connected Edition)
Date: 2009-12-11

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## java.lang
Class Runtime

    java.lang.Object
      java.lang.Runtime

    @TransactionType(value=NOT_SUPPORTED)
    public class Runtime

extends Object

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.

This Java Card class is a subset of the CLDC 1.1 Runtime class. Some interfaces, methods and/or variables have been pruned, and/or other methods simplified, in an effort to reduce the size of this class and/or eliminate dependencies on unsupported features.

Since:
  JDK1.0, CLDC 1.0, Java Card 3.0
See Also:
  `getRuntime()`

Method Summary
`long` | `freeMemory()` Returns the amount of free memory in the system.
`void` | `gc()` Runs the garbage collector.
`static Runtime` | `getRuntime()` Returns the runtime object associated with the current Java application.
`long` | `totalMemory()` Returns the total amount of memory in the Java Virtual Machine.

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Method Detail

### getRuntime

    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 Java Card RE-owned `Runtime` object associated with the current Java application.

### freeMemory

    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.

### totalMemory

    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.

### gc

    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 even if the `gc` method is not invoked explicitly.

  The method `System.gc()` is the conventional and convenient means of invoking this method.

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Copyright (c) 2009 Sun Microsystems, Inc. All rights reserved.