Package nz.org.riskscape.picocli

Class CommandLine.PropertiesDefaultProvider

java.lang.Object
nz.org.riskscape.picocli.CommandLine.PropertiesDefaultProvider
All Implemented Interfaces:
CommandLine.IDefaultValueProvider
Enclosing class:
CommandLine
public static class CommandLine.PropertiesDefaultProvider extends Object implements CommandLine.IDefaultValueProvider

IDefaultValueProvider implementation that loads default values for command line options and positional parameters from a properties file or Properties object.

Location

By default, this implementation tries to find a properties file named &quot;.<YOURCOMMAND>.properties&quot; in the user home directory, where &quot;<YOURCOMMAND>&quot; is the name of the command. If a command has aliases in addition to its name, these aliases are also used to try to find the properties file. For example: 
  @Command(name = "git", defaultValueProvider = PropertiesDefaultProvider.class)
  class Git { }

The above will try to load default values from new File(System.getProperty(&quot;user.home&quot;), &quot;.git.properties&quot;).

The location of the properties file can also be controlled with system property &quot;picocli.defaults.<YOURCOMMAND>.path&quot;, in which case the value of the property must be the path to the file containing the default values.

The location of the properties file may also be specified programmatically. For example: 

  CommandLine cmd = new CommandLine(new MyCommand());
  File defaultsFile = new File("path/to/config/mycommand.properties");
  cmd.setDefaultValueProvider(new PropertiesDefaultProvider(defaultsFile));
  cmd.execute(args);

Format

For options, the key is either the descriptionKey, or the option's longest name.

For positional parameters, the key is either the descriptionKey, or the positional parameter's param label.

End users may not know what the descriptionKey of your options and positional parameters are, so be sure to document that with your application.

Subcommands

The default values for options and positional parameters of subcommands can be included in the properties file for the top-level command, so that end users need to maintain only a single file. This can be achieved by prefixing the key with the command's qualified name. For example, to give the <code>git commit</code> command's --cleanup option a default value of strip, define a key of git.commit.cleanup and assign it a default value. 

  # /home/remko/.git.properties
  git.commit.cleanup = strip

Since:
4.1

  • Constructor Details

    • PropertiesDefaultProvider

      public PropertiesDefaultProvider()

      Default constructor, used when this default value provider is specified in the annotations: 

        @Command(name = "mycmd",
      defaultValueProvider = PropertiesDefaultProvider.class)
  class MyCommand // ...

      This loads default values from a properties file named &quot;.mycmd.properties&quot; in the user home directory.

      The location of the properties file can also be controlled with system property &quot;picocli.defaults.<YOURCOMMAND>.path&quot;, in which case the value of the property must be the path to the file containing the default values.

      See Also:

    • PropertiesDefaultProvider

      public PropertiesDefaultProvider(Properties properties)

      This constructor loads default values from the specified properties object. This may be used programmatically. For example: 

        CommandLine cmd = new CommandLine(new MyCommand());
  Properties defaults = getProperties();
  cmd.setDefaultValueProvider(new PropertiesDefaultProvider(defaults));
  cmd.execute(args);

      Parameters:
      properties - the properties containing the default values
      See Also:

    • PropertiesDefaultProvider

      public PropertiesDefaultProvider(File file)

      This constructor loads default values from the specified properties file. This may be used programmatically. For example: 

        CommandLine cmd = new CommandLine(new MyCommand());
  File defaultsFile = new File("path/to/config/file.properties");
  cmd.setDefaultValueProvider(new PropertiesDefaultProvider(defaultsFile));
  cmd.execute(args);

      Parameters:
      file - the file to load default values from. Must be non-null and must contain default values in the standard java Properties format.
      See Also:

  • Method Details

    • defaultValue

      public String defaultValue(CommandLine.Model.ArgSpec argSpec) throws Exception
      Description copied from interface: CommandLine.IDefaultValueProvider
      Returns the default value for an option or positional parameter or null. The returned value is converted to the type of the option/positional parameter via the same type converter used when populating this option/positional parameter from a command line argument.
      Specified by:
      defaultValue in interface CommandLine.IDefaultValueProvider
      Parameters:
      argSpec - the option or positional parameter, never null
      Returns:
      the default value for the option or positional parameter, or null if this provider has no default value for the specified option or positional parameter
      Throws:
      Exception - when there was a problem obtaining the default value

    • toString

      public String toString()
      Overrides:
      toString in class Object