From c9ee7adcc59f2cb686594b537e336ecc01896a0d Mon Sep 17 00:00:00 2001
From: Joel Leitch <joel.leitch@gmail.com>
Date: Fri, 3 Jun 2011 19:02:28 +0000
Subject: [PATCH] Start using JsonNull.INSTANCE everywhere and remove creation
 method.

---
 .../main/java/com/google/gson/JsonNull.java   | 20 +++----------------
 .../java/com/google/gson/JsonNullTest.java    |  4 ++--
 .../java/com/google/gson/JsonObjectTest.java  |  7 ++++---
 3 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/gson/src/main/java/com/google/gson/JsonNull.java b/gson/src/main/java/com/google/gson/JsonNull.java
index 26e391e6..9426c200 100755
--- a/gson/src/main/java/com/google/gson/JsonNull.java
+++ b/gson/src/main/java/com/google/gson/JsonNull.java
@@ -28,7 +28,7 @@ import java.io.IOException;
 public final class JsonNull extends JsonElement {
   /**
    * singleton for JsonNull
-   * 
+   *
    * @since 1.8
    */
   public static final JsonNull INSTANCE = new JsonNull();
@@ -46,7 +46,7 @@ public final class JsonNull extends JsonElement {
   protected void toString(Appendable sb, Escaper escaper) throws IOException {
     sb.append("null");
   }
-  
+
   /**
    * All instances of JsonNull have the same hash code since they are indistinguishable
    */
@@ -54,7 +54,7 @@ public final class JsonNull extends JsonElement {
   public int hashCode() {
     return JsonNull.class.hashCode();
   }
-  
+
   /**
    * All instances of JsonNull are the same
    */
@@ -62,18 +62,4 @@ public final class JsonNull extends JsonElement {
   public boolean equals(Object other) {
     return this == other || other instanceof JsonNull;
   }
-  
-  /**
-   * Creation method used to return an instance of a {@link JsonNull}.  To reduce the memory
-   * footprint, a single object has been created for this class; therefore the same instance is
-   * being returned for each invocation of this method. This method is kept private since we 
-   * prefer the users to use {@link JsonNull#JsonNull()} which is similar to how other JsonElements
-   * are created. Note that all instances of JsonNull return true for {@link #equals(Object)} 
-   * when compared to each other.
-   *
-   * @return a instance of a {@link JsonNull}
-   */
-  static JsonNull createJsonNull() {
-    return INSTANCE;
-  }
 }
diff --git a/gson/src/test/java/com/google/gson/JsonNullTest.java b/gson/src/test/java/com/google/gson/JsonNullTest.java
index 9e3c6ea9..e928ab9f 100644
--- a/gson/src/test/java/com/google/gson/JsonNullTest.java
+++ b/gson/src/test/java/com/google/gson/JsonNullTest.java
@@ -17,6 +17,7 @@
 package com.google.gson;
 
 import com.google.gson.common.MoreAsserts;
+
 import junit.framework.TestCase;
 
 /**
@@ -28,7 +29,6 @@ public final class JsonNullTest extends TestCase {
   public void testEqualsAndHashcode() {
     MoreAsserts.assertEqualsAndHashCode(new JsonNull(), new JsonNull());
     MoreAsserts.assertEqualsAndHashCode(new JsonNull(), JsonNull.INSTANCE);
-    MoreAsserts.assertEqualsAndHashCode(new JsonNull(), JsonNull.createJsonNull());
-    MoreAsserts.assertEqualsAndHashCode(JsonNull.createJsonNull(), JsonNull.createJsonNull());
+    MoreAsserts.assertEqualsAndHashCode(JsonNull.INSTANCE, JsonNull.INSTANCE);
   }
 }
diff --git a/gson/src/test/java/com/google/gson/JsonObjectTest.java b/gson/src/test/java/com/google/gson/JsonObjectTest.java
index 9065ca71..d0747a6e 100644
--- a/gson/src/test/java/com/google/gson/JsonObjectTest.java
+++ b/gson/src/test/java/com/google/gson/JsonObjectTest.java
@@ -17,6 +17,7 @@
 package com.google.gson;
 
 import com.google.gson.common.MoreAsserts;
+
 import junit.framework.TestCase;
 
 /**
@@ -56,12 +57,12 @@ public class JsonObjectTest extends TestCase {
   public void testAddingNullOrEmptyPropertyName() throws Exception {
     JsonObject jsonObj = new JsonObject();
     try {
-      jsonObj.add(null, JsonNull.createJsonNull());
+      jsonObj.add(null, JsonNull.INSTANCE);
       fail("Should not allow null property names.");
     } catch (NullPointerException expected) { }
 
-    jsonObj.add("", JsonNull.createJsonNull());
-    jsonObj.add("   \t", JsonNull.createJsonNull());
+    jsonObj.add("", JsonNull.INSTANCE);
+    jsonObj.add("   \t", JsonNull.INSTANCE);
   }
 
   public void testAddingBooleanProperties() throws Exception {