Class JdiDefaultExecutionControl

jdk.jshell.execution.JdiDefaultExecutionControl

All Implemented Interfaces:: AutoCloseable, ExecutionControl

public class JdiDefaultExecutionControl extends JdiExecutionControl

The implementation of ExecutionControl that the JShell-core uses by default. Launches a remote process -- the "remote agent". Interfaces to the remote agent over a socket and via JDI. Designed to work with RemoteExecutionControl.

Since:: 9

Nested Class Summary

Modifier and Type	Class	Description
`static interface`	`JdiDefaultExecutionControl.JdiStarter`	Start an external process where the user's snippets can be run.

Nested classes/interfaces declared in interface ExecutionControl

ExecutionControl.ClassBytecodes, ExecutionControl.ClassInstallException, ExecutionControl.EngineTerminationException, ExecutionControl.ExecutionControlException, ExecutionControl.InternalException, ExecutionControl.NotImplementedException, ExecutionControl.ResolutionException, ExecutionControl.RunException, ExecutionControl.StoppedException, ExecutionControl.UserException

Modifier and Type	Interface	Description
`static final class`	`ExecutionControl.ClassBytecodes`	Bundles class name with class bytecodes.
`static class`	`ExecutionControl.ClassInstallException`	A class install (load or redefine) encountered a problem.
`static class`	`ExecutionControl.EngineTerminationException`	Unbidden execution engine termination has occurred.
`static class`	`ExecutionControl.ExecutionControlException`	The abstract base of all `ExecutionControl` exceptions.
`static class`	`ExecutionControl.InternalException`	An internal problem has occurred.
`static class`	`ExecutionControl.NotImplementedException`	The command is not implemented.
`static class`	`ExecutionControl.ResolutionException`	An exception indicating that a `DeclarationSnippet` with unresolved references has been encountered.
`static class`	`ExecutionControl.RunException`	The abstract base of of exceptions specific to running user code.
`static class`	`ExecutionControl.StoppedException`	An exception indicating that an `ExecutionControl.invoke(java.lang.String, java.lang.String)` (or theoretically a `ExecutionControl.varValue(java.lang.String, java.lang.String)`) has been interrupted by a `ExecutionControl.stop()`.
`static class`	`ExecutionControl.UserException`	A 'normal' user exception occurred.

Method Summary

Modifier and Type	Method	Description
`String`	`invoke(String classname, String methodname)`	Invokes an executable Snippet by calling a method on the specified wrapper class.
`void`	`stop()`	Interrupts a running remote invoke by manipulating remote variables and sending a stop via JDI.
`protected VirtualMachine`	`vm()`	Returns the JDI `VirtualMachine` instance.

Methods declared in class JdiExecutionControl

redefine, referenceType

Modifier and Type	Method	Description
`void`	`redefine(ExecutionControl.ClassBytecodes[] cbcs)`	Redefine the specified classes.
`protected ReferenceType`	`referenceType(VirtualMachine vm, String name)`	Returns the JDI `ReferenceType` corresponding to the specified class name.

Methods declared in class StreamingExecutionControl

addToClasspath, close, extensionCommand, load, varValue

Modifier and Type	Method	Description
`void`	`addToClasspath(String path)`	Adds the path to the execution class path.
`void`	`close()`	Closes the execution engine.
`Object`	`extensionCommand(String command, Object arg)`	Run a non-standard command (or a standard command from a newer version).
`void`	`load(ExecutionControl.ClassBytecodes[] cbcs)`	Attempts to load new classes.
`String`	`varValue(String classname, String varname)`	Returns the value of a variable.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Method Details

invoke

public String invoke(String classname, String methodname) throws ExecutionControl.RunException, ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Description copied from interface: ExecutionControl

Invokes an executable Snippet by calling a method on the specified wrapper class. The method must have no arguments and return String.

Specified by:: invoke in interface ExecutionControl
Overrides:: invoke in class StreamingExecutionControl
Parameters:: classname - the class whose method should be invoked; methodname - the name of method to invoke
Returns:: the result of the execution or null if no result
Throws:: ExecutionControl.UserException - the invoke raised a user exception; ExecutionControl.ResolutionException - the invoke attempted to directly or indirectly invoke an unresolved snippet; ExecutionControl.StoppedException - if the invoke() was canceled by ExecutionControl.stop(); ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.InternalException - an internal problem occurred; ExecutionControl.RunException

stop

public void stop() throws ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Interrupts a running remote invoke by manipulating remote variables and sending a stop via JDI.

Throws:: ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.InternalException - an internal problem occurred

vm

protected VirtualMachine vm() throws ExecutionControl.EngineTerminationException

Description copied from class: JdiExecutionControl

Returns the JDI VirtualMachine instance.

Specified by:: vm in class JdiExecutionControl
Returns:: the virtual machine
Throws:: ExecutionControl.EngineTerminationException - if the VM is dead/disconnected

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.