software.amazon.smithy.cli

Class Cli

java.lang.Object

software.amazon.smithy.cli.Cli

public final class Cli
extends java.lang.Object

This class provides a very basic CLI abstraction.

Note: The argument parser does not support setting an argument using foo=bar.

The following options are automatically added to each command:

• --help | -h: Prints subcommand help text.
• --debug: Prints debug information, including exception stack traces.
• --no-color: Explicitly disables ANSI colors.
• --force-color: Explicitly enables ANSI colors.
• --stacktrace: Prints the stacktrace of any CLI exception that is thrown.
• --logging: Sets the log level to one of OFF, SEVERE, WARNING, INFO, FINE, ALL.

Why are we not using a library for this? Because parsing command line options isn't difficult, we don't need to take a dependency, this code uses no reflection to improve startup time. We can control exactly what CLI features are supported in case we want to migrate to a library or event a different language.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEBUG
static java.lang.String	FORCE_COLOR
static java.lang.String	HELP
static java.lang.String	LOGGING
static java.lang.String	NO_COLOR
static java.lang.String	STACKTRACE

Constructor Summary

Constructors

Constructor and Description
Cli(java.lang.String applicationName) Creates a new CLI with the given name.
Cli(java.lang.String applicationName, java.lang.ClassLoader classLoader) Creates a new CLI with the given name.

Method Summary

Modifier and Type	Method and Description
void	addCommand(Command command) Adds a subcommand to the CLI.
static java.util.function.Consumer<java.lang.String>	getStderr() Gets the stderr consumer.
static java.util.function.Consumer<java.lang.String>	getStdout() Gets the stdout consumer.
void	run(java.lang.String[] args) Execute the command line using the given arguments.
void	setConfigureLogging(boolean configureLogging) Set to true to configure logging for the CLI.
static void	setStderr(java.util.function.Consumer<java.lang.String> printer) Configures a custom STDERR printer.
static void	setStdout(java.util.function.Consumer<java.lang.String> printer) Configures a custom STDOUT printer.
static void	setUseAnsiColors(boolean useAnsiColors) Explicitly configures whether or not to use ANSI colors.
static void	stderr(java.lang.Object message) Write a line of text to the configured STDERR.
static void	stdout(java.lang.Object message) Write a line of text to the configured STDOUT.

Methods inherited from class java.lang.Object

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

Field Detail

HELP

public static final java.lang.String HELP

See Also:

Constant Field Values

NO_COLOR

public static final java.lang.String NO_COLOR

See Also:

Constant Field Values

FORCE_COLOR

public static final java.lang.String FORCE_COLOR

See Also:

Constant Field Values

DEBUG

public static final java.lang.String DEBUG

See Also:

Constant Field Values

STACKTRACE

public static final java.lang.String STACKTRACE

See Also:

Constant Field Values

LOGGING

public static final java.lang.String LOGGING

See Also:

Constant Field Values

Constructor Detail

Cli

public Cli(java.lang.String applicationName)

Creates a new CLI with the given name.

Parameters:

applicationName - Name of the CLI application.

Cli

public Cli(java.lang.String applicationName,
           java.lang.ClassLoader classLoader)

Creates a new CLI with the given name.

Parameters:

applicationName - Name of the CLI application.

classLoader - ClassLoader to use when invoking commands.

Method Detail

addCommand

public void addCommand(Command command)

Adds a subcommand to the CLI.

Parameters:

command - Command to add.

setConfigureLogging

public void setConfigureLogging(boolean configureLogging)

Set to true to configure logging for the CLI.

Parameters:

configureLogging - Set to true to configure logging.

run

public void run(java.lang.String[] args)

Execute the command line using the given arguments.

Parameters:

args - Arguments to parse.

setStdout

public static void setStdout(java.util.function.Consumer<java.lang.String> printer)

Configures a custom STDOUT printer.

Parameters:

printer - Consumer responsible for writing to STDOUT.

setStderr

public static void setStderr(java.util.function.Consumer<java.lang.String> printer)

Configures a custom STDERR printer.

Parameters:

printer - Consumer responsible for writing to STDERR.

getStdout

public static java.util.function.Consumer<java.lang.String> getStdout()

Gets the stdout consumer.

Returns:

Returns the stdout consumer.

getStderr

public static java.util.function.Consumer<java.lang.String> getStderr()

Gets the stderr consumer.

Returns:

Returns the stderr consumer.

stdout

public static void stdout(java.lang.Object message)

Write a line of text to the configured STDOUT.

Parameters:

message - Message to write.

stderr

public static void stderr(java.lang.Object message)

Write a line of text to the configured STDERR.

Parameters:

message - Message to write.

setUseAnsiColors

public static void setUseAnsiColors(boolean useAnsiColors)

Explicitly configures whether or not to use ANSI colors.

Parameters:

useAnsiColors - Set to true or false to enable/disable.