JsonObject: better .stream(), use Map.entry

src/main/java/io/vertx/core/json/JsonObject.java

@@ -18,6 +18,7 @@
 import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import static io.vertx.core.json.impl.JsonUtil.*;
 import static java.time.format.DateTimeFormatter.ISO_INSTANT;
@@ -1114,7 +1115,13 @@ public Map<String, Object> getMap() {
    * @return a Stream
    */
   public Stream<Map.Entry<String, Object>> stream() {
-    return asStream(iterator());
+    // JsonUtil.asStream(iterator()) is too generic
+    return StreamSupport.stream(spliterator(), false);
+  }
+
+  @Override
+  public Spliterator<Map.Entry<String,Object>> spliterator() {
+    return Spliterators.spliterator(iterator(), map.size(), Spliterator.DISTINCT | Spliterator.NONNULL);
   }
 
   /**
@@ -1275,7 +1282,9 @@ public Map.Entry<String, Object> next() {
       final Object wrapped = wrapJsonValue(val);
 
       if (val != wrapped) {
-        return new Entry(entry.getKey(), wrapped);
+        // Map.entry disallows null keys and values: we disallow null keys,
+        // (val != wrapped) skips null values (wrapJsonValue doesn't wrap null)
+        return Map.entry(entry.getKey(), wrapped);
       }
 
       return entry;
@@ -1286,29 +1295,4 @@ public void remove() {
       mapIter.remove();
     }
   }
-
-  private static final class Entry implements Map.Entry<String, Object> {
-    final String key;
-    final Object value;
-
-    public Entry(String key, Object value) {
-      this.key = key;
-      this.value = value;
-    }
-
-    @Override
-    public String getKey() {
-      return key;
-    }
-
-    @Override
-    public Object getValue() {
-      return value;
-    }
-
-    @Override
-    public Object setValue(Object value) {
-      throw new UnsupportedOperationException();
-    }
-  }
 }

src/test/java/io/vertx/core/json/JsonObjectTest.java

@@ -12,6 +12,7 @@
 package io.vertx.core.json;
 
 import io.vertx.core.buffer.Buffer;
+import io.vertx.core.json.impl.JsonUtil;
 import io.vertx.core.shareddata.Shareable;
 import io.vertx.test.core.TestUtils;
 import org.junit.Before;
@@ -1973,4 +1974,48 @@ public void testJsonObjectOfArgs() {
   public void testJsonObjectOfEmpty() {
     assertEquals(new JsonObject(), JsonObject.of());
   }
+
+  @Test
+  public void testNull() {
+    assertEquals(JsonObject.of(), JsonObject.of());
+    assertFalse(JsonObject.of().equals(null));
+    assertFalse(JsonObject.of().equals(new JsonObject(){}));
+    assertNull(JsonUtil.wrapJsonValue(null));
+
+    JsonObject jo = JsonObject.of("k", null, "", null);
+
+    AtomicInteger cnt = new AtomicInteger();
+    jo.iterator().forEachRemaining(e -> {
+      assertNotNull(e.getKey());
+      assertNull(e.getValue());// null is ok
+      cnt.incrementAndGet();
+    });
+    assertEquals(2, cnt.get());
+
+    assertEquals("=null, k=null",
+      jo.stream().sorted(Map.Entry.comparingByKey())
+        .map(e -> e.getKey()+"="+e.getValue()).collect(Collectors.joining(", ")));
+  }
+
+  @Test
+  public void testBuffer() {
+    JsonObject jo = new JsonObject("{\"k\": 1}");
+    assertEquals("{\"k\":1}", jo.toString());
+    assertEquals("{\"k\":1}", jo.toBuffer().toString());
+    assertEquals("{\"k\":1}", jo.toBuffer().toJson().toString());
+
+    Buffer buf = Buffer.buffer();
+    buf.appendLong(Long.MIN_VALUE);
+    jo.writeToBuffer(buf);
+    JsonObject jo0 = JsonObject.of("aaa", 111, "BBB", 222);
+    jo0.writeToBuffer(buf);
+
+    assertEquals(Long.MIN_VALUE, buf.getLong(0));
+    JsonObject jo1 = JsonObject.of("x", 0);
+    int index = jo1.readFromBuffer(8, buf);
+    assertEquals(jo, jo1);
+    JsonObject jo2 = JsonObject.of("x", 0);
+    jo2.readFromBuffer(index, buf);
+    assertEquals(jo0, jo2);
+  }
 }