Java™ Debug Interface

The Java^TM Debug Interface (JDI) is a high level Java API providing information useful for debuggers and similiar systems needing access to the running state of a (usually remote) virtual machine.

The JDI provides introspective access to a running virtual machine's state, Class, Array, Interface, and primitive types, and instances of those types.

The JDI also provides explicit control over a virtual machine's execution. The ability to suspend and resume threads, and to set breakpoints, watchpoints, ... Notification of exceptions, class loading, thread creation... The ability to inspect a suspended thread's state, local variables, stack backtrace...

JDI is the highest-layer of the Java Platform Debugger Architecture (JPDA). For more information on the Java Platform Debugger Architecture, see the Java Platform Debugger Architecture documentation for this release and the Java Platform Debugger Architecture website.

Global Exceptions:

This section documents exceptions which apply to the entire API and are thus not documented on individual methods.

VMMismatchException

Any method on a Mirror that takes a Mirror as an parameter directly or indirectly (e.g., as a element in a List) will throw VMMismatchException if the mirrors are from different virtual machines.

NullPointerException

Any method which takes a Object as an parameter will throw NullPointerException if null is passed directly or indirectly -- unless null is explicitly mentioned as a valid parameter.

NOTE: The exceptions below may be thrown whenever the specified conditions are met but a guarantee that they are thrown only exists when a valid result cannot be returned.

VMDisconnectedException

Any method on ObjectReference, ReferenceType, EventRequest, StackFrame, or VirtualMachine or which takes one of these directly or indirectly as an parameter may throw VMDisconnectedException if the target VM is disconnected and the VMDisconnectEvent has been or is available to be read from the EventQueue.

VMOutOfMemoryException

Any method on ObjectReference, ReferenceType, EventRequest, StackFrame, or VirtualMachine or which takes one of these directly or indirectly as an parameter may throw VMOutOfMemoryException if the target VM has run out of memory.

ObjectCollectedException

Any method on ObjectReference or which directly or indirectly takes ObjectReference as parameter may throw ObjectCollectedException if the mirrored object has been garbage collected.

Any method on ReferenceType or which directly or indirectly takes ReferenceType as parameter may throw ObjectCollectedException if the mirrored type has been unloaded.