Site Tools


Smart Card Solution

User Manual

JavaCard API Samples

Java Card Specification

Knowledge Sharing


3.4 Contexts

Each applet running on a Java Card virtual machine is associated with an execution context. The Java Card virtual machine uses the context of the current frame to enforce security policies for inter-applet operations.

There is a one-to-one mapping between contexts and packages in which applets are defined. An easy way to think of a context is as the runtime equivalent of a package, since Java packages are compile-time constructs and have no direct representation at runtime. As a consequence, all applet instances from the same package will share the same context.

The Java Card Runtime Environment also has its own context. Framework objects execute in this Java Card RE context.

The context of the currently executing method is known as the current context. Every object in a Java Card virtual machine is owned by a particular context. The owning context is the context that was current when the object was created.

When a method in one context successfully invokes a method on an object in another context, the Java Card virtual machine performs a context switch. Afterwards the invoked method's context becomes the current context. When the invoked method returns, the current context is switched back to the previous context.

javacard/jcvm/3.4_contexts.txt · Last modified: 2017/05/13 04:10 (external edit)