Support of conversion to java.time classes

src/main/java/com/beust/jcommander/converters/InstantConverter.java

@@ -0,0 +1,30 @@
+package com.beust.jcommander.converters;
+
+import java.time.Instant;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter to {@link Instant}.
+ */
+public final class InstantConverter extends JavaTimeConverter<Instant> {
+
+  public InstantConverter(String optionName) {
+    super(optionName, Instant.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_INSTANT);
+  }
+
+  @Override
+  protected Instant parse(String value, DateTimeFormatter formatter) {
+    try {
+      long ms = Long.parseLong(value);
+      return Instant.ofEpochMilli(ms);
+    } catch (NumberFormatException e) {
+      return formatter.parse(value, Instant::from);
+    }
+  }
+}

src/main/java/com/beust/jcommander/converters/JavaTimeConverter.java

@@ -0,0 +1,80 @@
+package com.beust.jcommander.converters;
+
+import com.beust.jcommander.ParameterException;
+
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+import java.time.temporal.TemporalAccessor;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * Base class for all {@link java.time} converters.
+ *
+ * @param <T> concrete type to parse into
+ */
+public abstract class JavaTimeConverter<T extends TemporalAccessor> extends BaseConverter<T> {
+
+  private final Class<T> toClass;
+
+  /**
+   * Inheritor constructors should have only 1 parameter - optionName.
+   *
+   * @param optionName name of the option
+   * @param toClass    type to parse into
+   */
+  protected JavaTimeConverter(String optionName, Class<T> toClass) {
+    super(optionName);
+    this.toClass = toClass;
+  }
+
+  @Override
+  public final T convert(String value) {
+    return supportedFormats().stream()
+            .map(new Mapper(value))
+            .filter(Objects::nonNull)
+            .findFirst()
+            .orElseThrow(() -> new ParameterException(errorMessage(value)));
+  }
+
+  /**
+   * Supported formats for this type, e.g. {@code HH:mm:ss}
+   *
+   * @return list of supported formats
+   */
+  protected abstract List<DateTimeFormatter> supportedFormats();
+
+  /**
+   * Parse the value using the specified formatter.
+   *
+   * @param value value to parse
+   * @param formatter formatter specifying supported format
+   * @return parsed value
+   */
+  protected abstract T parse(String value, DateTimeFormatter formatter);
+
+  private String errorMessage(String value) {
+    return getErrorString(value, "a " + toClass.getSimpleName());
+  }
+
+  private final class Mapper implements Function<DateTimeFormatter, T> {
+
+    private final String value;
+
+    private Mapper(String value) {
+      this.value = value;
+    }
+
+    @Override
+    public T apply(DateTimeFormatter formatter) {
+      try {
+        return parse(value, formatter);
+      } catch (DateTimeParseException exc) {
+        return null;
+      } catch (Exception exc) {
+        throw new ParameterException(errorMessage(value), exc);
+      }
+    }
+  }
+}

src/main/java/com/beust/jcommander/converters/LocalDateConverter.java

@@ -0,0 +1,25 @@
+package com.beust.jcommander.converters;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter to {@link LocalDate}.
+ */
+public class LocalDateConverter extends JavaTimeConverter<LocalDate> {
+
+  public LocalDateConverter(String optionName) {
+    super(optionName, LocalDate.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_LOCAL_DATE, DateTimeFormatter.ofPattern("dd-MM-yyyy"));
+  }
+
+  @Override
+  protected LocalDate parse(String value, DateTimeFormatter formatter) {
+    return LocalDate.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/converters/LocalDateTimeConverter.java

@@ -0,0 +1,29 @@
+package com.beust.jcommander.converters;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
+import java.util.List;
+
+/**
+ * Converter for {@link LocalDateTime}.
+ */
+public class LocalDateTimeConverter extends JavaTimeConverter<LocalDateTime> {
+
+  public LocalDateTimeConverter(String optionName) {
+    super(optionName, LocalDateTime.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(
+            DateTimeFormatter.ISO_LOCAL_DATE_TIME,
+            new DateTimeFormatterBuilder().appendPattern("dd-MM-yyyy").appendLiteral('T').append(DateTimeFormatter.ISO_LOCAL_TIME).toFormatter()
+    );
+  }
+
+  @Override
+  protected LocalDateTime parse(String value, DateTimeFormatter formatter) {
+    return LocalDateTime.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/converters/LocalTimeConverter.java

@@ -0,0 +1,25 @@
+package com.beust.jcommander.converters;
+
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter for {@link LocalTime}.
+ */
+public class LocalTimeConverter extends JavaTimeConverter<LocalTime> {
+
+  public LocalTimeConverter(String optionName) {
+    super(optionName, LocalTime.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_LOCAL_TIME);
+  }
+
+  @Override
+  protected LocalTime parse(String value, DateTimeFormatter formatter) {
+    return LocalTime.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/converters/OffsetDateTimeConverter.java

@@ -0,0 +1,25 @@
+package com.beust.jcommander.converters;
+
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter for {@link OffsetDateTime}.
+ */
+public class OffsetDateTimeConverter extends JavaTimeConverter<OffsetDateTime> {
+
+  public OffsetDateTimeConverter(String optionName) {
+    super(optionName, OffsetDateTime.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
+  }
+
+  @Override
+  protected OffsetDateTime parse(String value, DateTimeFormatter formatter) {
+    return OffsetDateTime.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/converters/OffsetTimeConverter.java

@@ -0,0 +1,25 @@
+package com.beust.jcommander.converters;
+
+import java.time.OffsetTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter for {@link OffsetTime}.
+ */
+public class OffsetTimeConverter extends JavaTimeConverter<OffsetTime> {
+
+  public OffsetTimeConverter(String optionName) {
+    super(optionName, OffsetTime.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_OFFSET_TIME);
+  }
+
+  @Override
+  protected OffsetTime parse(String value, DateTimeFormatter formatter) {
+    return OffsetTime.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/converters/ZonedDateTimeConverter.java

@@ -0,0 +1,25 @@
+package com.beust.jcommander.converters;
+
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Converter for {@link ZonedDateTime}.
+ */
+public class ZonedDateTimeConverter extends JavaTimeConverter<ZonedDateTime> {
+
+  public ZonedDateTimeConverter(String optionName) {
+    super(optionName, ZonedDateTime.class);
+  }
+
+  @Override
+  protected List<DateTimeFormatter> supportedFormats() {
+    return List.of(DateTimeFormatter.ISO_ZONED_DATE_TIME);
+  }
+
+  @Override
+  protected ZonedDateTime parse(String value, DateTimeFormatter formatter) {
+    return ZonedDateTime.parse(value, formatter);
+  }
+}

src/main/java/com/beust/jcommander/internal/DefaultConverterFactory.java

@@ -26,16 +26,30 @@
 import com.beust.jcommander.converters.FileConverter;
 import com.beust.jcommander.converters.FloatConverter;
 import com.beust.jcommander.converters.ISO8601DateConverter;
+import com.beust.jcommander.converters.InstantConverter;
 import com.beust.jcommander.converters.IntegerConverter;
+import com.beust.jcommander.converters.LocalDateConverter;
+import com.beust.jcommander.converters.LocalDateTimeConverter;
+import com.beust.jcommander.converters.LocalTimeConverter;
 import com.beust.jcommander.converters.LongConverter;
+import com.beust.jcommander.converters.OffsetDateTimeConverter;
+import com.beust.jcommander.converters.OffsetTimeConverter;
 import com.beust.jcommander.converters.StringConverter;
 import com.beust.jcommander.converters.PathConverter;
 import com.beust.jcommander.converters.URIConverter;
 import com.beust.jcommander.converters.URLConverter;
+import com.beust.jcommander.converters.ZonedDateTimeConverter;
 
 import java.io.File;
 import java.lang.NoClassDefFoundError;
 import java.math.BigDecimal;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.OffsetDateTime;
+import java.time.OffsetTime;
+import java.time.ZonedDateTime;
 import java.util.Date;
 import java.net.URI;
 import java.net.URL;
@@ -67,6 +81,14 @@ public class DefaultConverterFactory implements IStringConverterFactory {
     classConverters.put(URI.class, URIConverter.class);
     classConverters.put(URL.class, URLConverter.class);
 
+    classConverters.put(Instant.class, InstantConverter.class);
+    classConverters.put(LocalDate.class, LocalDateConverter.class);
+    classConverters.put(LocalDateTime.class, LocalDateTimeConverter.class);
+    classConverters.put(LocalTime.class, LocalTimeConverter.class);
+    classConverters.put(OffsetDateTime.class, OffsetDateTimeConverter.class);
+    classConverters.put(OffsetTime.class, OffsetTimeConverter.class);
+    classConverters.put(ZonedDateTime.class, ZonedDateTimeConverter.class);
+
     try {
       classConverters.put(Path.class, PathConverter.class);
     } catch (NoClassDefFoundError ex) {

src/test/java/com/beust/jcommander/JCommanderTest.java

@@ -39,6 +39,14 @@
 import java.nio.file.Path;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.OffsetDateTime;
+import java.time.OffsetTime;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
 import java.util.*;
 import java.util.ResourceBundle;
 
@@ -1519,4 +1527,39 @@ public void validate(String name, Integer i) throws ParameterException {
             }
         }
     }
+
+    @Test
+    public void javaTimeTest() {
+        String[] argv = {
+                "-i", "0",
+                "-ld", "1970-01-12",
+                "-ldt", "1970-01-12T11:15:09.000000333",
+                "-lt", "11:15:09.000000333",
+                "-odt", "1970-01-12T11:15:09.000000333+01:00",
+                "-ot", "11:15:09.000000333+01:00",
+                "-zdt", "1970-01-12T11:15:09.000000333Z"
+        };
+        JavaTimeParameters params = new JavaTimeParameters();
+        JCommander.newBuilder().addObject(params).build().parse(argv);
+
+        Assert.assertEquals(params.instant, Instant.EPOCH, "Instant parsed incorrectly");
+
+        LocalDate localDate = LocalDate.of(1970, 1, 12);
+        Assert.assertEquals(params.localDate, localDate, "LocalDate parsed incorrectly");
+
+        LocalTime localTime = LocalTime.of(11, 15, 9, 333);
+        Assert.assertEquals(params.localDateTime, LocalDateTime.of(localDate, localTime), "LocalDateTime parsed incorrectly");
+
+        Assert.assertEquals(params.localTime, localTime, "LocalTime parsed incorrectly");
+
+        ZoneOffset zoneOffset = ZoneOffset.ofHours(1);
+        OffsetDateTime offsetDateTime = OffsetDateTime.of(localDate, localTime, zoneOffset);
+        Assert.assertEquals(params.offsetDateTime, offsetDateTime, "OffsetDateTime parsed incorrectly");
+
+        OffsetTime offsetTime = OffsetTime.of(localTime, zoneOffset);
+        Assert.assertEquals(params.offsetTime, offsetTime, "OffsetTime parsed incorrectly");
+
+        ZonedDateTime zonedDateTime = ZonedDateTime.of(localDate, localTime, ZoneOffset.UTC);
+        Assert.assertEquals(params.zonedDateTime, zonedDateTime, "ZonedDateTime parsed incorrectly");
+    }
 }