Issue #5: Support for DATE/TIME extraction.

pom.xml

@@ -191,6 +191,12 @@
 				<version>${junit.version}</version>
 				<scope>test</scope>
 			</dependency>
+
+			<dependency>
+				<groupId>org.slf4j</groupId>
+				<artifactId>slf4j-log4j12</artifactId>
+				<version>1.7.5</version>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 </project>

sas/pom.xml

@@ -23,5 +23,15 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+		    <groupId>joda-time</groupId>
+		    <artifactId>joda-time</artifactId>
+		    <version>2.8.2</version>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-log4j12</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
-</project>
+</project>

sas/src/main/java/org/eobjects/metamodel/sas/CountReaderCallback.java

@@ -34,8 +34,11 @@ public CountReaderCallback() {
     }
 
     @Override
-    public void column(int columnIndex, String columnName, String columnLabel, SasColumnType columnType,
-            int columnLength) {
+    public void column(int columnIndex,
+                       String columnName,
+                       String columnLabel,
+                       SasColumnType columnType,
+                       int columnLength) {
         // do nothing
     }
 

sas/src/main/java/org/eobjects/metamodel/sas/DateConversionException.java

@@ -0,0 +1,8 @@
+package org.eobjects.metamodel.sas;
+
+public class DateConversionException extends RuntimeException {
+
+    public DateConversionException(String msg, Object ... values) {
+        super(String.format(msg, values));
+    }
+}

sas/src/main/java/org/eobjects/metamodel/sas/DateTimeConverter.java

@@ -0,0 +1,85 @@
+package org.eobjects.metamodel.sas;
+
+import org.joda.time.DateTime;
+import org.joda.time.Period;
+
+public class DateTimeConverter {
+
+    private static final int MINYEAR= 1, MAXYEAR=9999, MINDAYS=-999999999, MAXDAYS=999999999;
+
+    public DateTime datetimeToJava(int dateSeconds) {
+        DateTime dt = new DateTime(1960, 1, 1, 0, 0).plusSeconds(dateSeconds);
+        return dt;
+    }
+
+    public DateTime date9ToJava(int date9) {
+
+        /*
+         * This bounding [MINDAYS, MAXDAYS] isn't actually part of the spec --
+         * it's a restriction that is inherited from the python implementation
+         * of the sas7bdat format (and the use of Python datetimes in that
+         * code), and it's here to make sure that the results of the two packages
+         * are mutually comparable.
+         */
+        if(date9 < MINDAYS || date9 > MAXDAYS) {
+            throw new DateConversionException(
+                    "date9=%d must fall within the range [%d, %d]",
+                    date9, MINDAYS, MAXDAYS);
+        }
+
+        DateTime dt = new DateTime(1960, 1, 1, 0, 0).plusDays(date9);
+
+        /*
+         * Same as above -- this is a Python-ism, which seems reasonable
+         * (until we start collecting clinical study data in the year 10,000)
+         * and is here to make sure that the two code bases are as functionally
+         * equivalent as possible (which helps for testing).
+         */
+        if(dt.getYear() < MINYEAR || dt.getYear() > MAXYEAR) {
+            throw new DateConversionException(
+                    "year=%d must fall within the range [%d, %d]",
+                    dt.getYear(), MINYEAR, MAXYEAR);
+        }
+
+        return dt;
+    }
+
+    public Period time5ToJavaPeriod(int time5) {
+        /*
+         * Carry over Python-determined time and timedelta bounds, see comment above.
+         */
+        if(time5 < MINDAYS || time5 > MAXDAYS) {
+            throw new DateConversionException(
+                    "time5=%d must fall within the range [%d, %d]",
+                    time5, MINDAYS, MAXDAYS);
+        }
+
+        /*
+         * This is confusing to me -- I don't know why, if we're only
+         * measuring seconds-within-a-day for a TIME-formatted value,
+         * we are storing _the total number of seconds since Jan 1, 1960_
+         * BUT that appears to be what's going on here.  <SIGH>
+         */
+        DateTime dt = new DateTime(1960, 1, 1, 0, 0).plusSeconds(time5);
+
+        /*
+         * Carry over Python-determined time and timedelta bounds, see comment above.
+         */
+        if(dt.getYear() < MINYEAR || dt.getYear() > MAXYEAR) {
+            throw new DateConversionException(
+                    "year=%d must fall within the range [%d, %d]",
+                    dt.getYear(), MINYEAR, MAXYEAR);
+        }
+
+        /*
+         * for TIME values, we only return the hours/minutes/seconds
+         * as a separate Period value.
+         */
+        int hours = dt.getHourOfDay();
+        int minutes = dt.getMinuteOfHour();
+        int seconds = dt.getSecondOfMinute();
+        int millis = dt.getMillisOfSecond();
+
+        return new Period(hours, minutes, seconds, millis);
+    }
+}

sas/src/main/java/org/eobjects/metamodel/sas/IO.java

@@ -95,6 +95,19 @@ public static double readDouble(byte[] buffer, int off) {
 		return bb.getDouble(off);
 	}
 
+	public static float readFloat(byte[] buffer, int off) {
+		ByteBuffer bb = ByteBuffer.wrap(buffer);
+		bb.order(ByteOrder.LITTLE_ENDIAN);
+		return bb.getFloat(off);
+	}
+
+	public static Long readLong(byte[] buffer, int off) {
+		return ByteBuffer
+				.wrap(buffer)
+				.order(ByteOrder.LITTLE_ENDIAN)
+				.getLong(off);
+	}
+
 	public static byte[] readBytes(byte[] data, int off, int len) {
 		if (data.length < off + len) {
 			throw new SasReaderException("readBytes failed! data.length: "

sas/src/main/java/org/eobjects/metamodel/sas/SasColumnType.java

@@ -26,5 +26,5 @@
  */
 public enum SasColumnType {
 
-	NUMERIC, CHARACTER;
+	NUMERIC, CHARACTER, DATE, TIME;
 }