rewrote parsing to allow time zone offset at any time accuracy

histream-core/src/test/java/de/sekmi/histream/TestDateTimeAccuracy.java

@@ -7,8 +7,11 @@ import java.time.format.DateTimeParseException;
 import java.time.format.ResolverStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.ChronoUnit;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.UnsupportedTemporalTypeException;
 
 import org.junit.Assert;
+import static org.junit.Assert.*;
 import org.junit.Test;
 
 public class TestDateTimeAccuracy {
@@ -34,10 +37,62 @@ public class TestDateTimeAccuracy {
 		a = DateTimeAccuracy.parse(formatter, "01.02.2003 13");
 		Assert.assertEquals(ChronoUnit.HOURS, a.getAccuracy());
 		Assert.assertEquals("2003-02-01T13", a.toPartialIso8601(null));
-		Assert.assertEquals("2003-02-01T13+08:00", a.toPartialIso8601(tz));
+		Assert.assertEquals("2003-02-01T21+0800", a.toPartialIso8601(tz));
 	}
 	
-	
+	@Test
+	public void verifyDateTimeFormatter(){
+		TemporalAccessor a;
+		DateTimeFormatter f = DateTimeFormatter.ISO_DATE_TIME;
+		// zone offset missing, field should be not available
+		a = f.parse("2001-02-03T04:05:06");
+		Assert.assertFalse(a.isSupported(ChronoField.OFFSET_SECONDS));
+		try{
+			a.get(ChronoField.OFFSET_SECONDS);
+			Assert.fail("Expected exception not thrown");
+		}catch( UnsupportedTemporalTypeException e ){
+			// expected outcome
+		}
+		// zero zone offset, field should be available
+		a = f.parse("2001-02-03T04:05:06Z");
+		Assert.assertEquals(0, a.get(ChronoField.OFFSET_SECONDS));
+		a = f.parse("2001-02-03T04:05:06+00:00");
+		Assert.assertEquals(0, a.get(ChronoField.OFFSET_SECONDS));
+		a = f.parse("2001-02-03T04:05"); // seconds can be omitted
+		// test the partial timestamp formatter
+		f = DateTimeFormatter.ofPattern("u[-M[-d['T'H[:m[:s[.S]]][X]]]]");
+	}
+
+	@Test
+	public void verifyParsingIncompleteIsoTimestamp() throws ParseException{
+		DateTimeAccuracy a;
+		a = DateTimeAccuracy.parsePartialIso8601("2001");
+		assertEquals(ChronoUnit.YEARS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02");
+		assertEquals(ChronoUnit.MONTHS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03");
+		assertEquals(ChronoUnit.DAYS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04");
+		assertEquals(ChronoUnit.HOURS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04:05");
+		assertEquals(ChronoUnit.MINUTES, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04:05:06");
+		assertEquals(ChronoUnit.SECONDS, a.getAccuracy());
+		// verify zone offset
+		// for second accuracy
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04:05:06+0800");
+		assertEquals(ChronoUnit.SECONDS, a.getAccuracy());
+		// zone offset calculation
+		assertEquals(DateTimeAccuracy.parsePartialIso8601("2001-02-02T20:05:06Z"), a);
+		
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04+0800");
+		assertEquals(ChronoUnit.HOURS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04Z");
+		assertEquals(ChronoUnit.HOURS, a.getAccuracy());
+		a = DateTimeAccuracy.parsePartialIso8601("2001-02-03T04:05+0800");
+		assertEquals(ChronoUnit.MINUTES, a.getAccuracy());
+		
+	}
 	@Test
 	public void testFormatExceedsText(){
 		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("d.M.u[ H[:m[:s]]]");
@@ -63,7 +118,7 @@ public class TestDateTimeAccuracy {
 		}
 		// TODO test more aspects of zone offset parsing
 		DateTimeAccuracy.parsePartialIso8601("2003-02-01T04:05:06Z");
-		DateTimeAccuracy a = DateTimeAccuracy.parsePartialIso8601("2003-02-01T04:05:06+01:00");
+		DateTimeAccuracy a = DateTimeAccuracy.parsePartialIso8601("2003-02-01T04:05:06+0100");
 		// make sure the date is adjusted to UTC
 		Assert.assertEquals(3, a.get(ChronoField.HOUR_OF_DAY));
 	}