edu.nmu.os.shell
Class CommandImpl

java.lang.Object
  |
  +--edu.nmu.os.shell.Command
        |
        +--edu.nmu.os.shell.CommandImpl

All Implemented Interfaces:

java.lang.Runnable

public class CommandImpl

extends Command

Encapsulates the functionality of a single shell command

Since:

jdk1.4

Version:

1.0, 01/24/2003

Author:

Matt Murphy

Constructor Summary

CommandImpl(Shell shell, java.lang.String string, java.io.InputStream in, java.io.PrintStream out, java.io.PrintStream err, java.lang.String[] args, java.lang.String program, boolean fork, boolean exit, boolean force)
Constructs a new CommandImpl

Method Summary

boolean	forceCurrentThread() Determines whether the Command should be run in the same Thread as the executor
boolean	fork() Determines whether this Command should be joined with immediately after its execution
java.lang.String[]	getArgs() Gets the parameters that will be given to the program when this Command is executed
java.io.PrintStream	getErr() Gets the PrintStream that should be used as NewSystem.err during execution
java.io.InputStream	getIn() Gets the InputStream that should be used as NewSystem.in during execution
java.io.PrintStream	getOut() Gets the PrintStream that should be used as NewSystem.out during execution
java.lang.String	getProgram() Gets the name of the program that will be run when this Command is executed
protected Shell	getShell()
boolean	isExit() Determines whether or not this Command is a command to exit the Shell
protected java.lang.Class	resolveClass(java.lang.String program) Resolves the given program as a Class
protected java.io.File	resolveExecutable(java.lang.String program) Resolves the given program as a File
java.lang.String	toString() Returns the string specified in the constructor

Methods inherited from class edu.nmu.os.shell.Command

isResolved, run

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandImpl

public CommandImpl(Shell shell,
                   java.lang.String string,
                   java.io.InputStream in,
                   java.io.PrintStream out,
                   java.io.PrintStream err,
                   java.lang.String[] args,
                   java.lang.String program,
                   boolean fork,
                   boolean exit,
                   boolean force)

Constructs a new CommandImpl

Parameters:

string - to be returned by toString()

in - to be returned by getIn()

out - to be returned by getOut()

err - to be returned by getErr()

args - to be returned by getArgs()

program - to be returned by getProgram()

fork - to be returned by fork()

exit - to be returned by isExit()

force - to be returned by forceCurrentThread()

Method Detail

getShell

protected Shell getShell()

Specified by:

getShell in class Command

getProgram

public java.lang.String getProgram()

Description copied from class: Command

Gets the name of the program that will be run when this Command is executed

Specified by:

getProgram in class Command

Returns:

the name of the program

getArgs

public java.lang.String[] getArgs()

Description copied from class: Command

Gets the parameters that will be given to the program when this Command is executed

Specified by:

getArgs in class Command

Returns:

the parameters

fork

public boolean fork()

Description copied from class: Command

Determines whether this Command should be joined with immediately after its execution

Specified by:

fork in class Command

Returns:

false if the executor should wait for the Thread to exit before continuing, true otherwise

getIn

public java.io.InputStream getIn()

Description copied from class: Command

Gets the InputStream that should be used as NewSystem.in during execution

Specified by:

getIn in class Command

Returns:

the InputStream

getOut

public java.io.PrintStream getOut()

Description copied from class: Command

Gets the PrintStream that should be used as NewSystem.out during execution

Specified by:

getOut in class Command

Returns:

the PrintStream

getErr

public java.io.PrintStream getErr()

Description copied from class: Command

Gets the PrintStream that should be used as NewSystem.err during execution

Specified by:

getErr in class Command

Returns:

the PrintStream

isExit

public boolean isExit()

Description copied from class: Command

Determines whether or not this Command is a command to exit the Shell

Specified by:

isExit in class Command

Returns:

true if the Shell should exit after execution, false othewise

forceCurrentThread

public boolean forceCurrentThread()

Description copied from class: Command

Determines whether the Command should be run in the same Thread as the executor

Specified by:

forceCurrentThread in class Command

Returns:

true if the Command should be run in the current Thread

toString

public java.lang.String toString()

Returns the string specified in the constructor

Overrides:

toString in class java.lang.Object

Returns:

this Command as a String

resolveClass

protected java.lang.Class resolveClass(java.lang.String program)
                                throws java.lang.ClassNotFoundException

Resolves the given program as a Class

Tries to resolve the Class to classes in the current Shell's classpath path if the default implementation is not sufficient

Overrides:

resolveClass in class Command

Parameters:

program - the name of the program to be resolved

Returns:

the resolved Class

Throws:

java.lang.ClassNotFoundException - if resolution was unsuccessful

resolveExecutable

protected java.io.File resolveExecutable(java.lang.String program)
                                  throws java.io.FileNotFoundException

Resolves the given program as a File

Tries to resolve the File to files in the current Shell's path

Overrides:

resolveExecutable in class Command

Parameters:

program - the name of the program to be resolved

Returns:

the resolved File

Throws:

java.io.FileNotFoundException - if resolution was unsuccessful