Unified handling of empty input: return always null

diff --git a/src/main/java/de/juplo/jackson/SimpleMapper.java b/src/main/java/de/juplo/jackson/SimpleMapper.java
index d7f108c..3dd5509 100644 (file)
--- a/src/main/java/de/juplo/jackson/SimpleMapper.java
+++ b/src/main/java/de/juplo/jackson/SimpleMapper.java
@@ -5,7 +5,6 @@ import com.fasterxml.jackson.core.JsonLocation;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
 import java.io.IOException;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.LinkedList;
@@ -15,7 +14,6 @@ import java.util.Map.Entry;
 import java.util.NoSuchElementException;
 import java.util.Spliterator;
 import static java.util.Spliterator.IMMUTABLE;
-import java.util.Spliterators;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
@@ -41,10 +39,7 @@ public abstract class SimpleMapper
     JsonToken token = parser.nextToken();
 
     if (token == null)
-    {
-      LOG.warn("empty input");
-      return Spliterators.emptySpliterator();
-    }
+      return null;
 
     if (!JsonToken.START_ARRAY.equals(token))
       fail(parser, "The root-element must be an array!");
@@ -140,10 +135,7 @@ public abstract class SimpleMapper
     JsonToken token = parser.nextToken();
 
     if (token == null)
-    {
-      LOG.warn("empty input");
-      return Spliterators.emptySpliterator();
-    }
+      return null;
 
     if (!JsonToken.START_OBJECT.equals(token))
       fail(parser, "The root-element must be an object!");
@@ -263,10 +255,7 @@ public abstract class SimpleMapper
     JsonToken token = parser.nextToken();
 
     if (token == null)
-    {
-      LOG.warn("empty input");
-      return Collections.EMPTY_LIST;
-    }
+      return null;
 
     if (!JsonToken.START_ARRAY.equals(token))
       fail(parser, "The root-element must be an array!");
@@ -284,10 +273,7 @@ public abstract class SimpleMapper
     JsonToken token = parser.nextToken();
 
     if (token == null)
-    {
-      LOG.warn("empty input");
-      return Collections.EMPTY_MAP;
-    }
+      return null;
 
     if (!JsonToken.START_OBJECT.equals(token))
       fail(parser, "The root-element must be an object!");
@@ -305,10 +291,7 @@ public abstract class SimpleMapper
     JsonToken token = parser.nextToken();
 
     if (token == null)
-    {
-      LOG.warn("empty input");
       return null;
-    }
 
     switch (token)
     {

diff --git a/src/test/java/de/juplo/jackson/SimpleMapperTest.java b/src/test/java/de/juplo/jackson/SimpleMapperTest.java
index 075acca..33fb8a3 100644 (file)
--- a/src/test/java/de/juplo/jackson/SimpleMapperTest.java
+++ b/src/test/java/de/juplo/jackson/SimpleMapperTest.java
@@ -8,10 +8,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Spliterator;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
 import org.junit.Test;
 
 
@@ -30,40 +27,15 @@ public class SimpleMapperTest
     Spliterator<Object> spliterator;
 
     spliterator = SimpleMapper.getArraySpliterator(get("/empty/1.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Object t) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getArraySpliterator(get("/empty/2.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Object t) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getArraySpliterator(get("/empty/3.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Object t) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getArraySpliterator(get("/empty/4.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Object t) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getArraySpliterator(get("/empty/5.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Object t) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
   }
 
   @Test
@@ -72,15 +44,15 @@ public class SimpleMapperTest
     List<Object> list;
 
     list = SimpleMapper.convertArray(get("/empty/1.json"));
-    assertEquals(0, list.size());
+    assertNull(list);
     list = SimpleMapper.convertArray(get("/empty/2.json"));
-    assertEquals(0, list.size());
+    assertNull(list);
     list = SimpleMapper.convertArray(get("/empty/3.json"));
-    assertEquals(0, list.size());
+    assertNull(list);
     list = SimpleMapper.convertArray(get("/empty/4.json"));
-    assertEquals(0, list.size());
+    assertNull(list);
     list = SimpleMapper.convertArray(get("/empty/5.json"));
-    assertEquals(0, list.size());
+    assertNull(list);
   }
 
   @Test
@@ -89,40 +61,15 @@ public class SimpleMapperTest
     Spliterator<Entry<String, Object>> spliterator;
 
     spliterator = SimpleMapper.getObjectSpliterator(get("/empty/1.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Entry<String, Object> e) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getObjectSpliterator(get("/empty/2.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Entry<String, Object> e) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getObjectSpliterator(get("/empty/3.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Entry<String, Object> e) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getObjectSpliterator(get("/empty/4.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Entry<String, Object> e) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
     spliterator = SimpleMapper.getObjectSpliterator(get("/empty/5.json"));
-    assertFalse(
-        "The created splitter should have no entries",
-        spliterator.tryAdvance((Entry<String, Object> e) ->
-        {
-          fail("The consumer should never be called!");
-        }));
+    assertNull(spliterator);
   }
 
   @Test
@@ -131,15 +78,15 @@ public class SimpleMapperTest
     Map<String, Object> map;
 
     map = SimpleMapper.convertObject(get("/empty/1.json"));
-    assertEquals(0, map.size());
+    assertNull(map);
     map = SimpleMapper.convertObject(get("/empty/2.json"));
-    assertEquals(0, map.size());
+    assertNull(map);
     map = SimpleMapper.convertObject(get("/empty/3.json"));
-    assertEquals(0, map.size());
+    assertNull(map);
     map = SimpleMapper.convertObject(get("/empty/4.json"));
-    assertEquals(0, map.size());
+    assertNull(map);
     map = SimpleMapper.convertObject(get("/empty/5.json"));
-    assertEquals(0, map.size());
+    assertNull(map);
   }
 
   @Test