Make it possible to return null on missing chunks, rather than the exception

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@897847 13f79535-47bb-0310-9956-ffa450edef68

src/scratchpad/src/org/apache/poi/hsmf/MAPIMessage.java

@@ -51,6 +51,8 @@ public class MAPIMessage extends POIDocument {
 	private RecipientChunks recipientChunks;
 	private AttachmentChunks[] attachmentChunks;
 	
+	private boolean returnNullOnMissingChunk = false;
+
 	/**
 	 * Constructor for creating new files.
 	 *
@@ -125,7 +127,11 @@ public class MAPIMessage extends POIDocument {
 	 */
 	public String getStringFromChunk(StringChunk chunk) throws ChunkNotFoundException {
 	   if(chunk == null) {
-	      throw new ChunkNotFoundException();
+	      if(returnNullOnMissingChunk) {
+	         return null;
+	      } else {
+	         throw new ChunkNotFoundException();
+	      }
 	   }
 	   return chunk.getValue();
 	}
@@ -230,6 +236,8 @@ public class MAPIMessage extends POIDocument {
 	   if(mainChunks.submissionChunk != null) {
 	      return mainChunks.submissionChunk.getAcceptedAtTime();
 	   }
+	   if(returnNullOnMissingChunk)
+	      return null;
 	   throw new ChunkNotFoundException();
 	}
 
@@ -268,4 +276,25 @@ public class MAPIMessage extends POIDocument {
    public void write(OutputStream out) throws IOException {
       throw new UnsupportedOperationException("Writing isn't yet supported for HSMF, sorry");
    }
+
+
+   /**
+    * Will you get a null on a missing chunk, or a 
+    *  {@link ChunkNotFoundException} (default is the
+    *  exception).
+    */
+   public boolean isReturnNullOnMissingChunk() {
+      return returnNullOnMissingChunk;
+   }
+
+   /**
+    * Sets whether on asking for a missing chunk,
+    *  you get back null or a {@link ChunkNotFoundException}
+    *  (default is the exception). 
+    */
+   public void setReturnNullOnMissingChunk(boolean returnNullOnMissingChunk) {
+      this.returnNullOnMissingChunk = returnNullOnMissingChunk;
+   }
+   
+   
 }

src/scratchpad/testcases/org/apache/poi/hsmf/TestBasics.java

@@ -22,6 +22,7 @@ import java.io.IOException;
 import junit.framework.TestCase;
 
 import org.apache.poi.POIDataSamples;
+import org.apache.poi.hsmf.exceptions.ChunkNotFoundException;
 
 /**
  * Tests to verify that we can perform basic opperations on 
@@ -74,4 +75,31 @@ public final class TestBasics extends TestCase {
       assertEquals(0, outlook30.getAttachmentFiles().length);
       assertEquals(2, attachments.getAttachmentFiles().length);
 	}
+	
+	/**
+	 * Test missing chunks
+	 */
+	public void testMissingChunks() throws Exception {
+	   assertEquals(false, attachments.isReturnNullOnMissingChunk());
+
+	   try {
+	      attachments.getMessageDate();
+	      fail();
+	   } catch(ChunkNotFoundException e) {
+	      // Good
+	   }
+	   
+	   attachments.setReturnNullOnMissingChunk(true);
+	   
+	   assertEquals(null, attachments.getMessageDate());
+	   
+      attachments.setReturnNullOnMissingChunk(false);
+      
+      try {
+         attachments.getMessageDate();
+         fail();
+      } catch(ChunkNotFoundException e) {
+         // Good
+      }
+	}
 }