picocli

Class CommandLine

java.lang.Object

picocli.CommandLine

public class CommandLine
extends java.lang.Object

CommandLine interpreter that uses reflection to initialize an annotated domain object with values obtained from the command line arguments.

Example

import static picocli.CommandLine.*;

 @Command(header = "Encrypt FILE(s), or standard input, to standard output or to the output file.",
          version = "v1.2.3")
 public class Encrypt {

     @Parameters(type = File.class, description = "Any number of input files")
     private List<File> files = new ArrayList<File>();

     @Option(names = { "-o", "--out" }, description = "Output file (default: print to console)")
     private File outputFile;

     @Option(names = { "-v", "--verbose"}, description = "Verbosely list files processed")
     private boolean verbose;

     @Option(names = { "-h", "--help", "-?", "-help"}, usageHelp = true, description = "Display this help and exit")
     private boolean help;

     @Option(names = { "-V", "--version"}, versionHelp = true, description = "Display version info and exit")
     private boolean versionHelp;
 }
 

Use CommandLine to initialize a domain object as follows:

 public static void main(String... args) {
     Encrypt encrypt = new Encrypt();
     try {
         List<CommandLine> parsedCommands = new CommandLine(encrypt).parse(args);
         if (!CommandLine.printHelpIfRequested(parsedCommands, System.err, Help.Ansi.AUTO)) {
             runProgram(encrypt);
         }
     } catch (ParameterException ex) { // command line arguments could not be parsed
         System.err.println(ex.getMessage());
         ex.getCommandLine().usage(System.err);
     }
 }
 

Invoke the above program with some command line arguments. The below are all equivalent:

 --verbose --out=outfile in1 in2
 --verbose --out outfile in1 in2
 -v --out=outfile in1 in2
 -v -o outfile in1 in2
 -v -o=outfile in1 in2
 -vo outfile in1 in2
 -vo=outfile in1 in2
 -v -ooutfile in1 in2
 -vooutfile in1 in2
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	CommandLine.Command Annotate your class with @Command when you want more control over the format of the generated help message.
static class	CommandLine.DefaultExceptionHandler Default exception handler that prints the exception message to the specified PrintStream, followed by the usage message for the command or subcommand whose input was invalid.
static class	CommandLine.DuplicateOptionAnnotationsException Exception indicating that multiple fields have been annotated with the same Option name.
static class	CommandLine.ExecutionException Exception indicating a problem while invoking a command or subcommand.
static class	CommandLine.Help A collection of methods and inner classes that provide fine-grained control over the contents and layout of the usage help message to display to end users when help is requested or invalid input values were specified.
static interface	CommandLine.IExceptionHandler Represents a function that can handle a ParameterException that occurred while parsing the command line arguments.
static interface	CommandLine.IFactory Factory for instantiating classes that are registered declaratively with annotation attributes, like CommandLine.Command.subcommands(), CommandLine.Option.converter(), CommandLine.Parameters.converter() and CommandLine.Command.versionProvider().
static class	CommandLine.InitializationException Exception indicating a problem during CommandLine initialization.
static interface	CommandLine.IParseResultHandler Represents a function that can process a List of CommandLine objects resulting from successfully parsing the command line arguments.
static interface	CommandLine.ITypeConverter<K> When parsing command line arguments and initializing fields annotated with @Option or @Parameters, String values can be converted to any type for which a ITypeConverter is registered.
static interface	CommandLine.IVersionProvider Provides version information for a command.
static class	CommandLine.MaxValuesforFieldExceededException Exception indicating that more values were specified for an option or parameter than its arity allows.
static class	CommandLine.MissingParameterException Exception indicating that a required parameter was not specified.
static class	CommandLine.MissingTypeConverterException Exception indicating that an annotated field had a type for which no CommandLine.ITypeConverter was registered.
static interface	CommandLine.Option Annotate fields in your class with @Option and picocli will initialize these fields when matching arguments are specified on the command line.
static class	CommandLine.OverwrittenOptionException Exception indicating that an option for a single-value option field has been specified multiple times on the command line.
static class	CommandLine.ParameterException Exception indicating something went wrong while parsing command line options.
static class	CommandLine.ParameterIndexGapException Exception indicating that there was a gap in the indices of the fields annotated with CommandLine.Parameters.
static interface	CommandLine.Parameters Fields annotated with @Parameters will be initialized with positional parameters.
static interface	CommandLine.ParentCommand Fields annotated with @ParentCommand will be initialized with the parent command of the current subcommand.
static class	CommandLine.PicocliException Base class of all exceptions thrown by picocli.CommandLine.
static class	CommandLine.Range Describes the number of parameters required and accepted by an option or a positional parameter.
static class	CommandLine.RunAll Command line parse result handler that prints help if requested, and otherwise executes the top-level command and all subcommands as Runnable or Callable.
static class	CommandLine.RunFirst Command line parse result handler that prints help if requested, and otherwise executes the top-level Runnable or Callable command.
static class	CommandLine.RunLast Command line parse result handler that prints help if requested, and otherwise executes the most specific Runnable or Callable subcommand.
static class	CommandLine.TypeConversionException Exception thrown by CommandLine.ITypeConverter implementations to indicate a String could not be converted.
static class	CommandLine.UnmatchedArgumentException Exception indicating that a command line argument could not be mapped to any of the fields annotated with CommandLine.Option or CommandLine.Parameters.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	VERSION This is picocli version "2.3.0".

Constructor Summary

Constructors

Constructor and Description
CommandLine(java.lang.Object command) Constructs a new CommandLine interpreter with the specified annotated object and a default subcommand factory.
CommandLine(java.lang.Object command, CommandLine.IFactory factory) Constructs a new CommandLine interpreter with the specified annotated object and object factory.

Method Summary

Methods

Modifier and Type	Method and Description
CommandLine	addSubcommand(java.lang.String name, java.lang.Object command) Registers a subcommand with the specified name.
static <C extends java.util.concurrent.Callable<T>,T> T	call(C callable, java.io.PrintStream out, CommandLine.Help.Ansi ansi, java.lang.String... args) Convenience method to allow command line application authors to avoid some boilerplate code in their application.
static <C extends java.util.concurrent.Callable<T>,T> T	call(C callable, java.io.PrintStream out, java.lang.String... args) Delegates to call(Callable, PrintStream, Help.Ansi, String...) with CommandLine.Help.Ansi.AUTO.
<T> T	getCommand() Returns the annotated object that this CommandLine instance was constructed with.
java.lang.String	getCommandName() Returns the command name (also called program name) displayed in the usage help synopsis.
CommandLine	getParent() Returns the command that this is a subcommand of, or null if this is a top-level command.
java.lang.String	getSeparator() Returns the String that separates option names from option values when parsing command line options.
java.util.Map<java.lang.String,CommandLine>	getSubcommands() Returns a map with the subcommands registered on this instance.
java.util.List<java.lang.String>	getUnmatchedArguments() Returns the list of unmatched command line arguments, if any.
boolean	isExpandAtFiles() Returns whether arguments starting with '@' should be treated as the path to an argument file and its contents should be expanded into separate arguments for each line in the specified file.
boolean	isOverwrittenOptionsAllowed() Returns whether options for single-value fields can be specified multiple times on the command line.
boolean	isStopAtPositional() Returns whether the parser interprets the first positional parameter as "end of options" so the remaining arguments are all treated as positional parameters.
boolean	isStopAtUnmatched() Returns whether the parser should stop interpreting options and positional parameters as soon as it encounters an unmatched option.
boolean	isUnmatchedArgumentsAllowed() Returns whether the end user may specify arguments on the command line that are not matched to any option or parameter fields.
boolean	isUsageHelpRequested() Returns true if an option annotated with CommandLine.Option.usageHelp() was specified on the command line.
boolean	isVersionHelpRequested() Returns true if an option annotated with CommandLine.Option.versionHelp() was specified on the command line.
java.util.List<CommandLine>	parse(java.lang.String... args) Parses the specified command line arguments and returns a list of CommandLine objects representing the top-level command and any subcommands (if any) that were recognized and initialized during the parsing process.
java.util.List<java.lang.Object>	parseWithHandler(CommandLine.IParseResultHandler handler, java.io.PrintStream out, java.lang.String... args) Returns the result of calling parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...) with Help.Ansi.AUTO and a new CommandLine.DefaultExceptionHandler in addition to the specified parse result handler, PrintStream, and the specified command line arguments.
java.util.List<java.lang.Object>	parseWithHandlers(CommandLine.IParseResultHandler handler, java.io.PrintStream out, CommandLine.Help.Ansi ansi, CommandLine.IExceptionHandler exceptionHandler, java.lang.String... args) Tries to parse the specified command line arguments, and if successful, delegates the processing of the resulting list of CommandLine objects to the specified handler.
static <T> T	populateCommand(T command, java.lang.String... args) Convenience method that initializes the specified annotated object from the specified command line arguments.
static boolean	printHelpIfRequested(java.util.List<CommandLine> parsedCommands, java.io.PrintStream out, CommandLine.Help.Ansi ansi) Helper method that may be useful when processing the list of CommandLine objects that result from successfully parsing command line arguments.
void	printVersionHelp(java.io.PrintStream out) Delegates to printVersionHelp(PrintStream, Help.Ansi) with the platform default.
void	printVersionHelp(java.io.PrintStream out, CommandLine.Help.Ansi ansi) Prints version information from the CommandLine.Command.version() annotation to the specified PrintStream.
void	printVersionHelp(java.io.PrintStream out, CommandLine.Help.Ansi ansi, java.lang.Object... params) Prints version information from the CommandLine.Command.version() annotation to the specified PrintStream.
<K> CommandLine	registerConverter(java.lang.Class<K> cls, CommandLine.ITypeConverter<K> converter) Registers the specified type converter for the specified class.
static <R extends java.lang.Runnable> void	run(R runnable, java.io.PrintStream out, CommandLine.Help.Ansi ansi, java.lang.String... args) Convenience method to allow command line application authors to avoid some boilerplate code in their application.
static <R extends java.lang.Runnable> void	run(R runnable, java.io.PrintStream out, java.lang.String... args) Delegates to run(Runnable, PrintStream, Help.Ansi, String...) with CommandLine.Help.Ansi.AUTO.
CommandLine	setCommandName(java.lang.String commandName) Sets the command name (also called program name) displayed in the usage help synopsis to the specified value.
CommandLine	setExpandAtFiles(boolean expandAtFiles) Sets whether arguments starting with '@' should be treated as the path to an argument file and its contents should be expanded into separate arguments for each line in the specified file.
CommandLine	setOverwrittenOptionsAllowed(boolean newValue) Sets whether options for single-value fields can be specified multiple times on the command line without a CommandLine.OverwrittenOptionException being thrown.
CommandLine	setSeparator(java.lang.String separator) Sets the String the parser uses to separate option names from option values to the specified value.
CommandLine	setStopAtPositional(boolean newValue) Sets whether the parser interprets the first positional parameter as "end of options" so the remaining arguments are all treated as positional parameters.
CommandLine	setStopAtUnmatched(boolean newValue) Sets whether the parser should stop interpreting options and positional parameters as soon as it encounters an unmatched option.
CommandLine	setUnmatchedArgumentsAllowed(boolean newValue) Sets whether the end user may specify unmatched arguments on the command line without a CommandLine.UnmatchedArgumentException being thrown.
static void	usage(java.lang.Object command, java.io.PrintStream out) Equivalent to new CommandLine(command).usage(out).
static void	usage(java.lang.Object command, java.io.PrintStream out, CommandLine.Help.Ansi ansi) Equivalent to new CommandLine(command).usage(out, ansi).
static void	usage(java.lang.Object command, java.io.PrintStream out, CommandLine.Help.ColorScheme colorScheme) Equivalent to new CommandLine(command).usage(out, colorScheme).
void	usage(java.io.PrintStream out) Delegates to usage(PrintStream, Help.Ansi) with the platform default.
void	usage(java.io.PrintStream out, CommandLine.Help.Ansi ansi) Delegates to usage(PrintStream, Help.ColorScheme) with the default color scheme.
void	usage(java.io.PrintStream out, CommandLine.Help.ColorScheme colorScheme) Prints a usage help message for the annotated command class to the specified PrintStream.

Methods inherited from class java.lang.Object

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

Field Detail

VERSION

public static final java.lang.String VERSION

This is picocli version "2.3.0".

See Also:

Constant Field Values

Constructor Detail

CommandLine

public CommandLine(java.lang.Object command)

Constructs a new CommandLine interpreter with the specified annotated object and a default subcommand factory. When the parse(String...) method is called, fields of the specified object that are annotated with @Option or @Parameters will be initialized based on command line arguments.

Parameters:

command - the object to initialize from the command line arguments

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine

public CommandLine(java.lang.Object command,
           CommandLine.IFactory factory)

Constructs a new CommandLine interpreter with the specified annotated object and object factory. When the parse(String...) method is called, fields of the specified object that are annotated with @Option or @Parameters will be initialized based on command line arguments.

Parameters:

command - the object to initialize from the command line arguments

factory - the factory used to create instances of subcommands that are registered declaratively with annotation attributes

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

Method Detail

addSubcommand

public CommandLine addSubcommand(java.lang.String name,
                        java.lang.Object command)

Registers a subcommand with the specified name. For example:

 CommandLine commandLine = new CommandLine(new Git())
         .addSubcommand("status",   new GitStatus())
         .addSubcommand("commit",   new GitCommit();
         .addSubcommand("add",      new GitAdd())
         .addSubcommand("branch",   new GitBranch())
         .addSubcommand("checkout", new GitCheckout())
         //...
         ;
 

The specified object can be an annotated object or a CommandLine instance with its own nested subcommands. For example:

 CommandLine commandLine = new CommandLine(new MainCommand())
         .addSubcommand("cmd1",                 new ChildCommand1()) // subcommand
         .addSubcommand("cmd2",                 new ChildCommand2())
         .addSubcommand("cmd3", new CommandLine(new ChildCommand3()) // subcommand with nested sub-subcommands
                 .addSubcommand("cmd3sub1",                 new GrandChild3Command1())
                 .addSubcommand("cmd3sub2",                 new GrandChild3Command2())
                 .addSubcommand("cmd3sub3", new CommandLine(new GrandChild3Command3()) // deeper nesting
                         .addSubcommand("cmd3sub3sub1", new GreatGrandChild3Command3_1())
                         .addSubcommand("cmd3sub3sub2", new GreatGrandChild3Command3_2())
                 )
         );
 

The default type converters are available on all subcommands and nested sub-subcommands, but custom type converters are registered only with the subcommand hierarchy as it existed when the custom type was registered. To ensure a custom type converter is available to all subcommands, register the type converter last, after adding subcommands.

See also the CommandLine.Command.subcommands() annotation to register subcommands declaratively.

Parameters:

name - the string to recognize on the command line as a subcommand

command - the object to initialize with command line arguments following the subcommand name. This may be a CommandLine instance with its own (nested) subcommands

Returns:

this CommandLine object, to allow method chaining

Since:

0.9.7

See Also:

registerConverter(Class, ITypeConverter), CommandLine.Command.subcommands()

getSubcommands

public java.util.Map<java.lang.String,CommandLine> getSubcommands()

Returns a map with the subcommands registered on this instance.

Returns:

a map with the registered subcommands

Since:

0.9.7

getParent

public CommandLine getParent()

Returns the command that this is a subcommand of, or null if this is a top-level command.

Returns:

the command that this is a subcommand of, or null if this is a top-level command

Since:

0.9.8

See Also:

addSubcommand(String, Object), CommandLine.Command.subcommands()

getCommand

public <T> T getCommand()

Returns the annotated object that this CommandLine instance was constructed with.

Type Parameters:

T - the type of the variable that the return value is being assigned to

Returns:

the annotated object that this CommandLine instance was constructed with

Since:

0.9.7

isUsageHelpRequested

public boolean isUsageHelpRequested()

Returns true if an option annotated with CommandLine.Option.usageHelp() was specified on the command line.

Returns:

whether the parser encountered an option annotated with CommandLine.Option.usageHelp().

Since:

0.9.8

isVersionHelpRequested

public boolean isVersionHelpRequested()

Returns true if an option annotated with CommandLine.Option.versionHelp() was specified on the command line.

Returns:

whether the parser encountered an option annotated with CommandLine.Option.versionHelp().

Since:

0.9.8

isOverwrittenOptionsAllowed

public boolean isOverwrittenOptionsAllowed()

Returns whether options for single-value fields can be specified multiple times on the command line. The default is false and a CommandLine.OverwrittenOptionException is thrown if this happens. When true, the last specified value is retained.

Returns:

true if options for single-value fields can be specified multiple times on the command line, false otherwise

Since:

0.9.7

setOverwrittenOptionsAllowed

public CommandLine setOverwrittenOptionsAllowed(boolean newValue)

Sets whether options for single-value fields can be specified multiple times on the command line without a CommandLine.OverwrittenOptionException being thrown.

The specified setting will be registered with this CommandLine and the full hierarchy of its subcommands and nested sub-subcommands at the moment this method is called. Subcommands added later will have the default setting. To ensure a setting is applied to all subcommands, call the setter last, after adding subcommands.

Parameters:

newValue - the new setting

Returns:

this CommandLine object, to allow method chaining

Since:

0.9.7

isStopAtPositional

public boolean isStopAtPositional()

Returns whether the parser interprets the first positional parameter as "end of options" so the remaining arguments are all treated as positional parameters. The default is false.

Returns:

true if all values following the first positional parameter should be treated as positional parameters, false otherwise

Since:

2.3

setStopAtPositional

public CommandLine setStopAtPositional(boolean newValue)

Sets whether the parser interprets the first positional parameter as "end of options" so the remaining arguments are all treated as positional parameters. The default is false.

The specified setting will be registered with this CommandLine and the full hierarchy of its subcommands and nested sub-subcommands at the moment this method is called. Subcommands added later will have the default setting. To ensure a setting is applied to all subcommands, call the setter last, after adding subcommands.

Parameters:

newValue - true if all values following the first positional parameter should be treated as positional parameters, false otherwise

Returns:

this CommandLine object, to allow method chaining

Since:

2.3

isStopAtUnmatched

public boolean isStopAtUnmatched()

Returns whether the parser should stop interpreting options and positional parameters as soon as it encounters an unmatched option. Unmatched options are arguments that look like an option but are not one of the known options, or positional arguments for which there is no available slots (the command has no positional parameters or their size is limited). The default is false.

Setting this flag to true automatically sets the unmatchedArgumentsAllowed flag to true also.

Returns:

true when an unmatched option should result in the remaining command line arguments to be added to the unmatchedArguments list

Since:

2.3

setStopAtUnmatched

public CommandLine setStopAtUnmatched(boolean newValue)

Sets whether the parser should stop interpreting options and positional parameters as soon as it encounters an unmatched option. Unmatched options are arguments that look like an option but are not one of the known options, or positional arguments for which there is no available slots (the command has no positional parameters or their size is limited). The default is false.

Setting this flag to true automatically sets the unmatchedArgumentsAllowed flag to true also.

The specified setting will be registered with this CommandLine and the full hierarchy of its subcommands and nested sub-subcommands at the moment this method is called. Subcommands added later will have the default setting. To ensure a setting is applied to all subcommands, call the setter last, after adding subcommands.

Parameters:

newValue - true when an unmatched option should result in the remaining command line arguments to be added to the unmatchedArguments list

Returns:

this CommandLine object, to allow method chaining

Since:

2.3

isUnmatchedArgumentsAllowed

public boolean isUnmatchedArgumentsAllowed()

Returns whether the end user may specify arguments on the command line that are not matched to any option or parameter fields. The default is false and a CommandLine.UnmatchedArgumentException is thrown if this happens. When true, the last unmatched arguments are available via the getUnmatchedArguments() method.

Returns:

true if the end use may specify unmatched arguments on the command line, false otherwise

Since:

0.9.7

See Also:

getUnmatchedArguments()

setUnmatchedArgumentsAllowed

public CommandLine setUnmatchedArgumentsAllowed(boolean newValue)

Sets whether the end user may specify unmatched arguments on the command line without a CommandLine.UnmatchedArgumentException being thrown.

The specified setting will be registered with this CommandLine and the full hierarchy of its subcommands and nested sub-subcommands at the moment this method is called. Subcommands added later will have the default setting. To ensure a setting is applied to all subcommands, call the setter last, after adding subcommands.

Parameters:

newValue - the new setting. When true, the last unmatched arguments are available via the getUnmatchedArguments() method.

Returns:

this CommandLine object, to allow method chaining

Since:

0.9.7

See Also:

getUnmatchedArguments()

getUnmatchedArguments

public java.util.List<java.lang.String> getUnmatchedArguments()

Returns the list of unmatched command line arguments, if any.

Returns:

the list of unmatched command line arguments or an empty list

Since:

0.9.7

See Also:

isUnmatchedArgumentsAllowed()

populateCommand

public static <T> T populateCommand(T command,
                    java.lang.String... args)

Convenience method that initializes the specified annotated object from the specified command line arguments.

This is equivalent to

 CommandLine cli = new CommandLine(command);
 cli.parse(args);
 return command;
 

Type Parameters:

T - the type of the annotated object

Parameters:

command - the object to initialize. This object contains fields annotated with @Option or @Parameters.

args - the command line arguments to parse

Returns:

the specified annotated object

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine.ParameterException - if the specified command line arguments are invalid

Since:

0.9.7

parse

public java.util.List<CommandLine> parse(java.lang.String... args)

Parses the specified command line arguments and returns a list of CommandLine objects representing the top-level command and any subcommands (if any) that were recognized and initialized during the parsing process.

If parsing succeeds, the first element in the returned list is always this CommandLine object. The returned list may contain more elements if subcommands were registered and these subcommands were initialized by matching command line arguments. If parsing fails, a CommandLine.ParameterException is thrown.

Parameters:

args - the command line arguments to parse

Returns:

a list with the top-level command and any subcommands initialized by this method

Throws:

CommandLine.ParameterException - if the specified command line arguments are invalid; use CommandLine.ParameterException.getCommandLine() to get the command or subcommand whose user input was invalid

printHelpIfRequested

public static boolean printHelpIfRequested(java.util.List<CommandLine> parsedCommands,
                           java.io.PrintStream out,
                           CommandLine.Help.Ansi ansi)

Helper method that may be useful when processing the list of CommandLine objects that result from successfully parsing command line arguments. This method prints out usage help if requested or version help if requested and returns true. Otherwise, if none of the specified CommandLine objects have help requested, this method returns false.

Note that this method only looks at the usageHelp and versionHelp attributes. The help attribute is ignored.

Parameters:

parsedCommands - the list of CommandLine objects to check if help was requested

out - the PrintStream to print help to if requested

ansi - for printing help messages using ANSI styles and colors

Returns:

true if help was printed, false otherwise

Since:

2.0

parseWithHandler

public java.util.List<java.lang.Object> parseWithHandler(CommandLine.IParseResultHandler handler,
                                                java.io.PrintStream out,
                                                java.lang.String... args)

Returns the result of calling parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...) with Help.Ansi.AUTO and a new CommandLine.DefaultExceptionHandler in addition to the specified parse result handler, PrintStream, and the specified command line arguments.

This is a convenience method intended to offer the same ease of use as the run and call methods, but with more flexibility and better support for nested subcommands.

Calling this method roughly expands to:

 try {
     List<CommandLine> parsedCommands = parse(args);
     return parseResultsHandler.handleParseResult(parsedCommands, out, Help.Ansi.AUTO);
 } catch (ParameterException ex) {
     return new DefaultExceptionHandler().handleException(ex, out, ansi, args);
 }
 

Picocli provides some default handlers that allow you to accomplish some common tasks with very little code. The following handlers are available:

• CommandLine.RunLast handler prints help if requested, and otherwise gets the last specified command or subcommand and tries to execute it as a Runnable or Callable.
• CommandLine.RunFirst handler prints help if requested, and otherwise executes the top-level command as a Runnable or Callable.
• CommandLine.RunAll handler prints help if requested, and otherwise executes all recognized commands and subcommands as Runnable or Callable tasks.
• CommandLine.DefaultExceptionHandler prints the error message followed by usage help

Parameters:

handler - the function that will process the result of successfully parsing the command line arguments

out - the PrintStream to print help to if requested

args - the command line arguments

Returns:

a list of results, or an empty list if there are no results

Throws:

CommandLine.ExecutionException - if the command line arguments were parsed successfully but a problem occurred while processing the parse results; use CommandLine.ExecutionException.getCommandLine() to get the command or subcommand where processing failed

Since:

2.0

See Also:

CommandLine.RunLast, CommandLine.RunAll

parseWithHandlers

public java.util.List<java.lang.Object> parseWithHandlers(CommandLine.IParseResultHandler handler,
                                                 java.io.PrintStream out,
                                                 CommandLine.Help.Ansi ansi,
                                                 CommandLine.IExceptionHandler exceptionHandler,
                                                 java.lang.String... args)

Tries to parse the specified command line arguments, and if successful, delegates the processing of the resulting list of CommandLine objects to the specified handler. If the command line arguments were invalid, the ParameterException thrown from the parse method is caught and passed to the specified CommandLine.IExceptionHandler.

This is a convenience method intended to offer the same ease of use as the run and call methods, but with more flexibility and better support for nested subcommands.

Calling this method roughly expands to:

 try {
     List<CommandLine> parsedCommands = parse(args);
     return parseResultsHandler.handleParseResult(parsedCommands, out, ansi);
 } catch (ParameterException ex) {
     return new exceptionHandler.handleException(ex, out, ansi, args);
 }
 

Picocli provides some default handlers that allow you to accomplish some common tasks with very little code. The following handlers are available:

• CommandLine.RunLast handler prints help if requested, and otherwise gets the last specified command or subcommand and tries to execute it as a Runnable or Callable.
• CommandLine.RunFirst handler prints help if requested, and otherwise executes the top-level command as a Runnable or Callable.
• CommandLine.RunAll handler prints help if requested, and otherwise executes all recognized commands and subcommands as Runnable or Callable tasks.
• CommandLine.DefaultExceptionHandler prints the error message followed by usage help

Parameters:

handler - the function that will process the result of successfully parsing the command line arguments

out - the PrintStream to print help to if requested

ansi - for printing help messages using ANSI styles and colors

exceptionHandler - the function that can handle the ParameterException thrown when the command line arguments are invalid

args - the command line arguments

Returns:

a list of results produced by the IParseResultHandler or the IExceptionHandler, or an empty list if there are no results

Throws:

CommandLine.ExecutionException - if the command line arguments were parsed successfully but a problem occurred while processing the parse result CommandLine objects; use CommandLine.ExecutionException.getCommandLine() to get the command or subcommand where processing failed

Since:

2.0

See Also:

CommandLine.RunLast, CommandLine.RunAll, CommandLine.DefaultExceptionHandler

usage

public static void usage(java.lang.Object command,
         java.io.PrintStream out)

Equivalent to new CommandLine(command).usage(out). See usage(PrintStream) for details.

Parameters:

command - the object annotated with CommandLine.Command, CommandLine.Option and CommandLine.Parameters

out - the print stream to print the help message to

Throws:

java.lang.IllegalArgumentException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

usage

public static void usage(java.lang.Object command,
         java.io.PrintStream out,
         CommandLine.Help.Ansi ansi)

Equivalent to new CommandLine(command).usage(out, ansi). See usage(PrintStream, Help.Ansi) for details.

Parameters:

command - the object annotated with CommandLine.Command, CommandLine.Option and CommandLine.Parameters

out - the print stream to print the help message to

ansi - whether the usage message should contain ANSI escape codes or not

Throws:

java.lang.IllegalArgumentException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

usage

public static void usage(java.lang.Object command,
         java.io.PrintStream out,
         CommandLine.Help.ColorScheme colorScheme)

Equivalent to new CommandLine(command).usage(out, colorScheme). See usage(PrintStream, Help.ColorScheme) for details.

Parameters:

command - the object annotated with CommandLine.Command, CommandLine.Option and CommandLine.Parameters

out - the print stream to print the help message to

colorScheme - the ColorScheme defining the styles for options, parameters and commands when ANSI is enabled

Throws:

java.lang.IllegalArgumentException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

usage

public void usage(java.io.PrintStream out)

Delegates to usage(PrintStream, Help.Ansi) with the platform default.

Parameters:

out - the printStream to print to

See Also:

usage(PrintStream, Help.ColorScheme)

usage

public void usage(java.io.PrintStream out,
         CommandLine.Help.Ansi ansi)

Delegates to usage(PrintStream, Help.ColorScheme) with the default color scheme.

Parameters:

out - the printStream to print to

ansi - whether the usage message should include ANSI escape codes or not

See Also:

usage(PrintStream, Help.ColorScheme)

usage

public void usage(java.io.PrintStream out,
         CommandLine.Help.ColorScheme colorScheme)

Prints a usage help message for the annotated command class to the specified PrintStream. Delegates construction of the usage help message to the CommandLine.Help inner class and is equivalent to:

 Help help = new Help(command).addAllSubcommands(getSubcommands());
 StringBuilder sb = new StringBuilder()
         .append(help.headerHeading())
         .append(help.header())
         .append(help.synopsisHeading())      //e.g. Usage:
         .append(help.synopsis())             //e.g. <main class> [OPTIONS] <command> [COMMAND-OPTIONS] [ARGUMENTS]
         .append(help.descriptionHeading())   //e.g. %nDescription:%n%n
         .append(help.description())          //e.g. {"Converts foos to bars.", "Use options to control conversion mode."}
         .append(help.parameterListHeading()) //e.g. %nPositional parameters:%n%n
         .append(help.parameterList())        //e.g. [FILE...] the files to convert
         .append(help.optionListHeading())    //e.g. %nOptions:%n%n
         .append(help.optionList())           //e.g. -h, --help   displays this help and exits
         .append(help.commandListHeading())   //e.g. %nCommands:%n%n
         .append(help.commandList())          //e.g.    add       adds the frup to the frooble
         .append(help.footerHeading())
         .append(help.footer());
 out.print(sb);
 

Annotate your class with CommandLine.Command to control many aspects of the usage help message, including the program name, text of section headings and section contents, and some aspects of the auto-generated sections of the usage help message.

To customize the auto-generated sections of the usage help message, like how option details are displayed, instantiate a CommandLine.Help object and use a CommandLine.Help.TextTable with more of fewer columns, a custom layout, and/or a custom option renderer for ultimate control over which aspects of an Option or Field are displayed where.

Parameters:

out - the PrintStream to print the usage help message to

colorScheme - the ColorScheme defining the styles for options, parameters and commands when ANSI is enabled

printVersionHelp

public void printVersionHelp(java.io.PrintStream out)

Delegates to printVersionHelp(PrintStream, Help.Ansi) with the platform default.

Parameters:

out - the printStream to print to

Since:

0.9.8

See Also:

printVersionHelp(PrintStream, Help.Ansi)

printVersionHelp

public void printVersionHelp(java.io.PrintStream out,
                    CommandLine.Help.Ansi ansi)

Prints version information from the CommandLine.Command.version() annotation to the specified PrintStream. Each element of the array of version strings is printed on a separate line. Version strings may contain markup for colors and style.

Parameters:

out - the printStream to print to

ansi - whether the usage message should include ANSI escape codes or not

Since:

0.9.8

See Also:

CommandLine.Command.version(), CommandLine.Option.versionHelp(), isVersionHelpRequested()

printVersionHelp

public void printVersionHelp(java.io.PrintStream out,
                    CommandLine.Help.Ansi ansi,
                    java.lang.Object... params)

Prints version information from the CommandLine.Command.version() annotation to the specified PrintStream. Each element of the array of version strings is formatted with the specified parameters, and printed on a separate line. Both version strings and parameters may contain markup for colors and style.

Parameters:

out - the printStream to print to

ansi - whether the usage message should include ANSI escape codes or not

params - Arguments referenced by the format specifiers in the version strings

Since:

1.0.0

See Also:

CommandLine.Command.version(), CommandLine.Option.versionHelp(), isVersionHelpRequested()

call

public static <C extends java.util.concurrent.Callable<T>,T> T call(C callable,
                                                    java.io.PrintStream out,
                                                    java.lang.String... args)

Delegates to call(Callable, PrintStream, Help.Ansi, String...) with CommandLine.Help.Ansi.AUTO.

From picocli v2.0, this method prints usage help or version help if requested, and any exceptions thrown by the Callable are caught and rethrown wrapped in an ExecutionException.

Type Parameters:

C - the annotated object must implement Callable

T - the return type of the most specific command (must implement Callable)

Parameters:

callable - the command to call when parsing succeeds.

out - the printStream to print to

args - the command line arguments to parse

Returns:

null if an error occurred while parsing the command line options, otherwise returns the result of calling the Callable

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine.ExecutionException - if the Callable throws an exception

See Also:

call(Callable, PrintStream, Help.Ansi, String...), parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...), CommandLine.RunFirst

call

public static <C extends java.util.concurrent.Callable<T>,T> T call(C callable,
                                                    java.io.PrintStream out,
                                                    CommandLine.Help.Ansi ansi,
                                                    java.lang.String... args)

Convenience method to allow command line application authors to avoid some boilerplate code in their application. The annotated object needs to implement Callable. Calling this method is equivalent to:

 CommandLine cmd = new CommandLine(callable);
 List<CommandLine> parsedCommands;
 try {
     parsedCommands = cmd.parse(args);
 } catch (ParameterException ex) {
     out.println(ex.getMessage());
     cmd.usage(out, ansi);
     return null;
 }
 if (CommandLine.printHelpIfRequested(parsedCommands, out, ansi)) {
     return null;
 }
 CommandLine last = parsedCommands.get(parsedCommands.size() - 1);
 try {
     Callable<Object> subcommand = last.getCommand();
     return subcommand.call();
 } catch (Exception ex) {
     throw new ExecutionException(last, "Error calling " + last.getCommand(), ex);
 }
 

If the specified Callable command has subcommands, the last subcommand specified on the command line is executed. Commands with subcommands may be interested in calling the parseWithHandler method with a CommandLine.RunAll handler or a custom handler.

From picocli v2.0, this method prints usage help or version help if requested, and any exceptions thrown by the Callable are caught and rethrown wrapped in an ExecutionException.

Type Parameters:

C - the annotated object must implement Callable

T - the return type of the specified Callable

Parameters:

callable - the command to call when parsing succeeds.

out - the printStream to print to

ansi - whether the usage message should include ANSI escape codes or not

args - the command line arguments to parse

Returns:

null if an error occurred while parsing the command line options, or if help was requested and printed. Otherwise returns the result of calling the Callable

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine.ExecutionException - if the Callable throws an exception

See Also:

parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...), CommandLine.RunLast

run

public static <R extends java.lang.Runnable> void run(R runnable,
                                      java.io.PrintStream out,
                                      java.lang.String... args)

Delegates to run(Runnable, PrintStream, Help.Ansi, String...) with CommandLine.Help.Ansi.AUTO.

From picocli v2.0, this method prints usage help or version help if requested, and any exceptions thrown by the Runnable are caught and rethrown wrapped in an ExecutionException.

Type Parameters:

R - the annotated object must implement Runnable

Parameters:

runnable - the command to run when parsing succeeds.

out - the printStream to print to

args - the command line arguments to parse

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine.ExecutionException - if the Runnable throws an exception

See Also:

run(Runnable, PrintStream, Help.Ansi, String...), parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...), CommandLine.RunFirst

run

public static <R extends java.lang.Runnable> void run(R runnable,
                                      java.io.PrintStream out,
                                      CommandLine.Help.Ansi ansi,
                                      java.lang.String... args)

Convenience method to allow command line application authors to avoid some boilerplate code in their application. The annotated object needs to implement Runnable. Calling this method is equivalent to:

 CommandLine cmd = new CommandLine(runnable);
 List<CommandLine> parsedCommands;
 try {
     parsedCommands = cmd.parse(args);
 } catch (ParameterException ex) {
     out.println(ex.getMessage());
     cmd.usage(out, ansi);
     return null;
 }
 if (CommandLine.printHelpIfRequested(parsedCommands, out, ansi)) {
     return null;
 }
 CommandLine last = parsedCommands.get(parsedCommands.size() - 1);
 try {
     Runnable subcommand = last.getCommand();
     subcommand.run();
 } catch (Exception ex) {
     throw new ExecutionException(last, "Error running " + last.getCommand(), ex);
 }
 

If the specified Runnable command has subcommands, the last subcommand specified on the command line is executed. Commands with subcommands may be interested in calling the parseWithHandler method with a CommandLine.RunAll handler or a custom handler.

From picocli v2.0, this method prints usage help or version help if requested, and any exceptions thrown by the Runnable are caught and rethrown wrapped in an ExecutionException.

Type Parameters:

R - the annotated object must implement Runnable

Parameters:

runnable - the command to run when parsing succeeds.

out - the printStream to print to

ansi - whether the usage message should include ANSI escape codes or not

args - the command line arguments to parse

Throws:

CommandLine.InitializationException - if the specified command object does not have a CommandLine.Command, CommandLine.Option or CommandLine.Parameters annotation

CommandLine.ExecutionException - if the Runnable throws an exception

See Also:

parseWithHandlers(IParseResultHandler, PrintStream, Help.Ansi, IExceptionHandler, String...), CommandLine.RunLast

registerConverter

public <K> CommandLine registerConverter(java.lang.Class<K> cls,
                                CommandLine.ITypeConverter<K> converter)

Registers the specified type converter for the specified class. When initializing fields annotated with CommandLine.Option, the field's type is used as a lookup key to find the associated type converter, and this type converter converts the original command line argument string value to the correct type.

Java 8 lambdas make it easy to register custom type converters:

 commandLine.registerConverter(java.nio.file.Path.class, s -> java.nio.file.Paths.get(s));
 commandLine.registerConverter(java.time.Duration.class, s -> java.time.Duration.parse(s));

Built-in type converters are pre-registered for the following java 1.5 types:

• all primitive types
• all primitive wrapper types: Boolean, Byte, Character, Double, Float, Integer, Long, Short
• any enum
• java.io.File
• java.math.BigDecimal
• java.math.BigInteger
• java.net.InetAddress
• java.net.URI
• java.net.URL
• java.nio.charset.Charset
• java.sql.Time
• java.util.Date
• java.util.UUID
• java.util.regex.Pattern
• StringBuilder
• CharSequence
• String

The specified converter will be registered with this CommandLine and the full hierarchy of its subcommands and nested sub-subcommands at the moment the converter is registered. Subcommands added later will not have this converter added automatically. To ensure a custom type converter is available to all subcommands, register the type converter last, after adding subcommands.

Type Parameters:

K - the target type

Parameters:

cls - the target class to convert parameter string values to

converter - the class capable of converting string values to the specified target type

Returns:

this CommandLine object, to allow method chaining

See Also:

addSubcommand(String, Object)

getSeparator

public java.lang.String getSeparator()

Returns the String that separates option names from option values when parsing command line options. by default.

Returns:

the String the parser uses to separate option names from option values

setSeparator

public CommandLine setSeparator(java.lang.String separator)

Sets the String the parser uses to separate option names from option values to the specified value. The separator may also be set declaratively with the CommandLine.Command.separator() annotation attribute.

Parameters:

separator - the String that separates option names from option values

Returns:

this CommandLine object, to allow method chaining

getCommandName

public java.lang.String getCommandName()

Returns the command name (also called program name) displayed in the usage help synopsis. by default.

Returns:

the command name (also called program name) displayed in the usage

Since:

2.0

setCommandName

public CommandLine setCommandName(java.lang.String commandName)

Sets the command name (also called program name) displayed in the usage help synopsis to the specified value. Note that this method only modifies the usage help message, it does not impact parsing behaviour. The command name may also be set declaratively with the CommandLine.Command.name() annotation attribute.

Parameters:

commandName - command name (also called program name) displayed in the usage help synopsis

Returns:

this CommandLine object, to allow method chaining

Since:

2.0

isExpandAtFiles

public boolean isExpandAtFiles()

Returns whether arguments starting with '@' should be treated as the path to an argument file and its contents should be expanded into separate arguments for each line in the specified file. This property is true by default.

Returns:

whether "argument files" or @files should be expanded into their content

Since:

2.1

setExpandAtFiles

public CommandLine setExpandAtFiles(boolean expandAtFiles)

Sets whether arguments starting with '@' should be treated as the path to an argument file and its contents should be expanded into separate arguments for each line in the specified file. (true by default.)

Parameters:

expandAtFiles - whether "argument files" or @files should be expanded into their content

Returns:

this CommandLine object, to allow method chaining

Since:

2.1