Interface CommandLine.ITypeConverter<K>

Type Parameters:
K - the type of the object that is the result of the conversion
All Known Implementing Classes:
CommandLine.BuiltIn.BigDecimalConverter, CommandLine.BuiltIn.BigIntegerConverter, CommandLine.BuiltIn.BooleanConverter, CommandLine.BuiltIn.ByteConverter, CommandLine.BuiltIn.CharacterConverter, CommandLine.BuiltIn.CharSequenceConverter, CommandLine.BuiltIn.CharsetConverter, CommandLine.BuiltIn.DoubleConverter, CommandLine.BuiltIn.FileConverter, CommandLine.BuiltIn.FloatConverter, CommandLine.BuiltIn.InetAddressConverter, CommandLine.BuiltIn.IntegerConverter, CommandLine.BuiltIn.ISO8601DateConverter, CommandLine.BuiltIn.ISO8601TimeConverter, CommandLine.BuiltIn.LongConverter, CommandLine.BuiltIn.PathConverter, CommandLine.BuiltIn.PatternConverter, CommandLine.BuiltIn.ShortConverter, CommandLine.BuiltIn.StringBuilderConverter, CommandLine.BuiltIn.StringConverter, CommandLine.BuiltIn.URIConverter, CommandLine.BuiltIn.URLConverter, CommandLine.BuiltIn.UUIDConverter
Enclosing class:
CommandLine
public 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.

This interface defines the contract for classes that know how to convert a String into some domain object. Custom converters can be registered with the CommandLine.registerConverter(Class, ITypeConverter) method.

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

  • Method Summary

    Modifier and Type
    Method
    Description
    K
    convert(String value)
    Converts the specified command line argument value to some domain object.

  • Method Details

    • convert

      K convert(String value) throws Exception
      Converts the specified command line argument value to some domain object.
      Parameters:
      value - the command line argument String value
      Returns:
      the resulting domain object
      Throws:
      Exception - an exception detailing what went wrong during the conversion