org.eclipse.osgi.framework.internal.core
Class FrameworkCommandInterpreter

java.lang.Object
  org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter

All Implemented Interfaces:

CommandInterpreter

public class FrameworkCommandInterpreter
extends java.lang.Object
implements CommandInterpreter

This class knows how to parse and execute the command line arguments to the FrameworkConsole. It attempts to pass the command to each registered CommandProvider until it finds one that knows what to do with it. FrameworkCommandInterpreter provides support for the "More" command which allows the operator to configure the number of lines to display before being prompted to continue. FrameworkCommandInterpreter provides several print methods which handle the "More" command.

Field Summary

protected int	currentLineCount The number of lines printed without user prompt.
protected static int	maxLineCount The maximum number of lines to print without user prompt.

Constructor Summary

FrameworkCommandInterpreter(java.lang.String cmdline, java.lang.Object[] commandProviders, FrameworkConsole con)
The constructor.

Method Summary

void	_more() Toggles the use of the more prompt for displayed output.
protected boolean	confirm(java.lang.String string, boolean defaultAnswer) Prompts the user for confirmation.
java.lang.Object	execute(java.lang.String cmd) Execute a command line as if it came from the end user.
java.lang.String	getHelp() Answer a string (may be as many lines as you like) with help texts that explain the command.
java.lang.String	nextArgument() Get the next argument in the input.
void	print(java.lang.Object o) Prints an object to the outputstream
void	printBundleResource(Bundle bundle, java.lang.String resource) Prints the given bundle resource if it exists
void	printDictionary(java.util.Dictionary dic, java.lang.String title) Prints the given dictionary sorted by keys.
void	println() Prints a empty line to the outputstream
void	println(java.lang.Object o) Prints an object to the output medium (appended with newline character).
void	printStackTrace(java.lang.Throwable t) Print a stack trace including nested exceptions.
protected int	prompt(java.lang.String string, int defaultAnswer) Prompts the user for input of a positive integer.
protected java.lang.String	prompt(java.lang.String string, java.lang.String defaultAnswer) Prompts the user for input from the input medium providing a default value.

Methods inherited from class java.lang.Object

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

Field Detail

maxLineCount

protected static int maxLineCount

The maximum number of lines to print without user prompt. 0 means no user prompt is required, the window is scrollable.

currentLineCount

protected int currentLineCount

The number of lines printed without user prompt.

Constructor Detail

FrameworkCommandInterpreter

public FrameworkCommandInterpreter(java.lang.String cmdline,
                                   java.lang.Object[] commandProviders,
                                   FrameworkConsole con)

The constructor. It turns the cmdline string into a StringTokenizer and remembers the input parms.

Method Detail

nextArgument

public java.lang.String nextArgument()

Get the next argument in the input. E.g. if the commandline is hello world, the _hello method will get "world" as the first argument.

Specified by:

nextArgument in interface CommandInterpreter

Returns:

A string containing the next argument on the command line

execute

public java.lang.Object execute(java.lang.String cmd)

Execute a command line as if it came from the end user. Searches the list of command providers using introspection until it finds one that contains a matching method. It searches for a method with the name "_cmd" where cmd is the command to execute. For example, for a command of "launch" execute searches for a method called "_launch".

Specified by:

execute in interface CommandInterpreter

Parameters:

cmd - The name of the command to execute.

Returns:

The object returned by the method executed.

print

public void print(java.lang.Object o)

Prints an object to the outputstream

Specified by:

print in interface CommandInterpreter

Parameters:

o - the object to be printed

println

public void println()

Prints a empty line to the outputstream

Specified by:

println in interface CommandInterpreter

printStackTrace

public void printStackTrace(java.lang.Throwable t)

Print a stack trace including nested exceptions.

Specified by:

printStackTrace in interface CommandInterpreter

Parameters:

t - The offending exception

println

public void println(java.lang.Object o)

Prints an object to the output medium (appended with newline character).

If running on the target environment, the user is prompted with '--more' if more than the configured number of lines have been printed without user prompt. This enables the user of the program to have control over scrolling.

For this to work properly you should not embed "\n" etc. into the string.

Specified by:

println in interface CommandInterpreter

Parameters:

o - the object to be printed

printDictionary

public void printDictionary(java.util.Dictionary dic,
                            java.lang.String title)

Prints the given dictionary sorted by keys.

Specified by:

printDictionary in interface CommandInterpreter

Parameters:

dic - the dictionary to print

title - the header to print above the key/value pairs

printBundleResource

public void printBundleResource(Bundle bundle,
                                java.lang.String resource)

Prints the given bundle resource if it exists

Specified by:

printBundleResource in interface CommandInterpreter

Parameters:

bundle - the bundle containing the resource

resource - the resource to print

getHelp

public java.lang.String getHelp()

Answer a string (may be as many lines as you like) with help texts that explain the command.

_more

public void _more()
           throws java.lang.Exception

Toggles the use of the more prompt for displayed output.

Throws:

java.lang.Exception

confirm

protected boolean confirm(java.lang.String string,
                          boolean defaultAnswer)

Prompts the user for confirmation.

Parameters:

string - the message to present to the user to confirm

defaultAnswer - the default result

Returns:

true if the user confirms; false otherwise.

prompt

protected java.lang.String prompt(java.lang.String string,
                                  java.lang.String defaultAnswer)

Prompts the user for input from the input medium providing a default value.

Parameters:

string - the message to present to the user

defaultAnswer - the string to use as a default return value

Returns:

The user provided string or the defaultAnswer, if user provided string was empty.

prompt

protected int prompt(java.lang.String string,
                     int defaultAnswer)

Prompts the user for input of a positive integer.

Parameters:

string - the message to present to the user

defaultAnswer - the integer to use as a default return value

Returns:

The user provided integer or the defaultAnswer, if user provided an empty input.