Implement comment

Allow again null values of literals in general, but prohibit it explicitly in the
MarcXmlEncoder.

- add test

Complements ad48cd4.

See #333 (comment).

Author: dr0i

metafacture-biblio/src/main/java/org/metafacture/biblio/marc21/MarcXmlEncoder.java

@@ -175,7 +175,7 @@ public void literal(final String name, final String value) {
         if (currentEntity.equals("")) {
             prettyPrintIndentation();
             writeRaw(String.format(CONTROLFIELD_OPEN_TEMPLATE, name));
-            if (value!=null)
+            if (value != null)
                 writeEscaped(value.trim());
             writeRaw(CONTROLFIELD_CLOSE);
             prettyPrintNewLine();

metafacture-biblio/src/test/java/org/metafacture/biblio/marc21/MarcXmlEncoderTest.java

@@ -204,4 +204,17 @@ public void sendAndClearDataWhenOnResetStream() {
         String actual = resultCollector.toString();
         assertEquals(expected, actual);
     }
+
+    @Test
+    public void shouldIgnoreNullValueOfLiteral() {
+        encoder.startRecord(RECORD_ID);
+        encoder.literal("type", null);
+        encoder.endRecord();
+        encoder.closeStream();
+        String expected = XML_DECLARATION + XML_ROOT_OPEN
+                + "<marc:record><marc:controlfield tag=\"type\"></marc:controlfield></marc:record>"
+                + XML_MARC_COLLECTION_END_TAG;
+        String actual = resultCollector.toString();
+        assertEquals(expected, actual);
+    }
 }

metamorph/src/main/java/org/metafacture/metamorph/Metamorph.java

@@ -323,10 +323,11 @@ protected void dispatch(final String path, final String value, final List<NamedV
         }
     }
 
-    private void send(final String path, final String value, final List<NamedValueReceiver> dataList, final boolean fallback) {
+    private void send(final String path, final String value, final List<NamedValueReceiver> dataList,
+            final boolean fallback) {
         for (final NamedValueReceiver data : dataList) {
-            String key=path;
-            if (fallback &&  value != null && elseNested) {
+            String key = path;
+            if (fallback && elseNested) {
                 if (flattener.getCurrentEntityName() != null) {
                     outputStreamReceiver.startEntity(flattener.getCurrentEntityName());
                     key = literalPatternOfEntityMarker.split(path)[1];
@@ -337,7 +338,7 @@ private void send(final String path, final String value, final List<NamedValueRe
             } catch (final RuntimeException e) {
                 errorHandler.error(e);
             }
-            if (fallback &&  value != null && elseNested) {
+            if (fallback && elseNested) {
                 if (flattener.getCurrentEntityName() != null) {
                     outputStreamReceiver.endEntity();
                 }