parsing date improved (when data is no available)

appointment-import/src/main/java/smash/appointment/parse/SubjectParser.java

@@ -142,6 +142,9 @@ public abstract class SubjectParser {
 	}
 
 	protected String getDate(Cell cell) {
+		if (cell == null) {
+			return "";
+		}
 		String result = null;
 		if (cell.getCellTypeEnum().equals(CellType.STRING)) {
 			result = getString(cell);

appointment-import/src/test/java/smash/appointment/parse/AllTests.java

@@ -11,6 +11,7 @@ import org.junit.runners.Suite.SuiteClasses;
 		RedcapParserTest.class, //
 
 		SubjectDaoTest.class, //
+		SubjectParserTest.class, //
 		XlsxCalendarProcessorTest.class, //
 })
 public class AllTests {

appointment-import/src/test/java/smash/appointment/parse/SubjectParserTest.java

+package smash.appointment.parse;
+
+import static org.junit.Assert.*;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.Test;
+
+public class SubjectParserTest {
+
+	@AfterClass
+	public static void tearDownAfterClass() throws Exception {
+	}
+
+	@Before
+	public void setUp() throws Exception {
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void testParseDate() {
+		SubjectParser parser = new PrcControlParser();
+		assertEquals("", parser.getDate(null));
+	}
+
+}