Package org.dellroad.jct.jshell

Class JShellShellSession

java.lang.Object

org.dellroad.jct.core.AbstractConsoleSession<Shell,ShellRequest>

org.dellroad.jct.core.AbstractShellSession

org.dellroad.jct.jshell.JShellShellSession

All Implemented Interfaces:

ConsoleSession<Shell,ShellRequest>, ShellSession

public class JShellShellSession
extends AbstractShellSession

A ShellSession that builds and executes a JShell instance.

The associated JShell instance can be customized in two ways:

• Override createBuilder() to customize the JavaShellToolBuilder used to create the JShell.
• Override modifyJShellParams() to customize the flags and parameters passed to JShell itself (these are the same as accepted by the jshell(1) command line tool). By default, the parameters passed are the the parameters given on the command line.

During execution, instances make themselves available to the current thread via getCurrent().

Field Summary

Fields

Modifier and Type	Field	Description
protected ClassLoader	localContextClassLoader

Fields inherited from class org.dellroad.jct.core.AbstractShellSession

exitValue, in, out

Fields inherited from class org.dellroad.jct.core.AbstractConsoleSession

owner, request

Constructor Summary

Constructors

Constructor	Description
JShellShellSession(JShellShell shell, ShellRequest request)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected PrintStream	buildOutputStream(org.jline.terminal.Terminal terminal)	Get the PrintStream to use for output from the given Terminal.
protected JavaShellToolBuilder	createBuilder()	Create and configure the JShell builder for this new session.
protected int	doExecute()	Execute this session.
static JShellShellSession	getCurrent()	Get the instance associated with the current thread.
JShellShell	getOwner()	Get the owner, i.e., the console component that created this session.
protected List<String>	modifyJShellParams(List<String> params)	Generate a list of command line flags and parameters to be passed to the JShell tool, given the arguments given on the shell command line for this command.
void	setLocalContextClassLoader(ClassLoader loader)	Configure a class loader to use with LocalContextExecutionControlProvider for local execution.

Methods inherited from class org.dellroad.jct.core.AbstractShellSession

buildInputStream, getExitValue, getInputStream, getOutputStream, setExitValue

Methods inherited from class org.dellroad.jct.core.AbstractConsoleSession

doInterrupt, execute, getRequest, interrupt

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.dellroad.jct.core.ConsoleSession

execute, getRequest, interrupt

Methods inherited from interface org.dellroad.jct.core.ShellSession

getErrorStream

Field Details

localContextClassLoader

protected ClassLoader localContextClassLoader

Constructor Details

JShellShellSession

public JShellShellSession(JShellShell shell,
 ShellRequest request)

Constructor.

Parameters:

shell - owning shell

request - shell request

Throws:

IllegalArgumentException - if any parameter is null

Method Details

getCurrent

public static JShellShellSession getCurrent()

Get the instance associated with the current thread.

This value is stored in an InheritableThreadLocal initialized when the JShell tool is started. As a result, it is accessible not only from the main JShell loop but also from the separate snippet execution threads created by JShell.

Returns:

session associated with the current thread, or null if not found

setLocalContextClassLoader

public void setLocalContextClassLoader(ClassLoader loader)

Configure a class loader to use with LocalContextExecutionControlProvider for local execution.

Parameters:

loader - class loader, or null for none

See Also:

• modifyJShellParams(java.util.List<java.lang.String>)

getOwner

public JShellShell getOwner()

Description copied from interface: ConsoleSession

Get the owner, i.e., the console component that created this session.

Specified by:

getOwner in interface ConsoleSession<Shell,ShellRequest>

Overrides:

getOwner in class AbstractConsoleSession<Shell,ShellRequest>

Returns:

owning component

buildOutputStream

protected PrintStream buildOutputStream(org.jline.terminal.Terminal terminal)

Description copied from class: AbstractShellSession

Get the PrintStream to use for output from the given Terminal.

Overrides:

buildOutputStream in class AbstractShellSession

Parameters:

terminal - terminal for shell

Returns:

corresponding output stream

doExecute

protected int doExecute()
                 throws InterruptedException

Description copied from class: AbstractConsoleSession

Execute this session.

This method is invoked by AbstractConsoleSession.execute() to do the actual work.

Specified by:

doExecute in class AbstractConsoleSession<Shell,ShellRequest>

Returns:

zero if successful, non-zero error code if an error occurred

Throws:

InterruptedException - if the current thread is interrupted

createBuilder

protected JavaShellToolBuilder createBuilder()

Create and configure the JShell builder for this new session.

Returns:

new builder

modifyJShellParams

protected List<String> modifyJShellParams(List<String> params)

Generate a list of command line flags and parameters to be passed to the JShell tool, given the arguments given on the shell command line for this command.

If this method is overridden to add or change this command's flags and/or parameters, then the full constructor taking customized help detail should be used to describe the new usage.

The implementation in JShellShellSession just returns the list unmodified unless a local context class loader has been configured, in which case the list is copied, modified by LocalContextExecutionControlProvider.modifyJShellFlags(java.lang.ClassLoader, java.util.List<java.lang.String>), and then returned.

Parameters:

params - parameters given to the shell command line

Returns:

flags and parameters for JShell

Throws:

IllegalArgumentException - if commandLineParams is null

See Also:

• setLocalContextClassLoader(java.lang.ClassLoader)