From 7aa1d0f6aa144d04389eab2faab603c853b23909 Mon Sep 17 00:00:00 2001
From: Inderjeet Singh <inder123@gmail.com>
Date: Fri, 24 Oct 2008 20:35:22 +0000
Subject: [PATCH] Reusing the JsonNull instance everywhere instead of
 recreating it. This is a minor optimization, which is possible because
 JsonNull is a stateless object.

---
 gson/src/main/java/com/google/gson/JsonNull.java          | 2 ++
 gson/src/main/java/com/google/gson/JsonParser.java        | 2 +-
 .../java/com/google/gson/JsonSerializationVisitor.java    | 8 ++++----
 gson/src/main/javacc/JsonParser.jj                        | 2 +-
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/gson/src/main/java/com/google/gson/JsonNull.java b/gson/src/main/java/com/google/gson/JsonNull.java
index 2b6909c0..92f197e6 100755
--- a/gson/src/main/java/com/google/gson/JsonNull.java
+++ b/gson/src/main/java/com/google/gson/JsonNull.java
@@ -25,6 +25,8 @@ package com.google.gson;
  */
 public final class JsonNull extends JsonElement {
 
+  static final JsonNull INSTANCE = new JsonNull();
+  
   @Override
   protected void toString(StringBuilder sb) {
     sb.append("null");
diff --git a/gson/src/main/java/com/google/gson/JsonParser.java b/gson/src/main/java/com/google/gson/JsonParser.java
index 8c79ec17..036c924e 100755
--- a/gson/src/main/java/com/google/gson/JsonParser.java
+++ b/gson/src/main/java/com/google/gson/JsonParser.java
@@ -51,7 +51,7 @@ final class JsonParser implements JsonParserConstants {
   }
 
   final private JsonNull JsonNull() throws ParseException {
-  JsonNull json = new JsonNull();
+  JsonNull json = JsonNull.INSTANCE;
     jj_consume_token(22);
     {if (true) return json;}
     throw new Error("Missing return statement in function");
diff --git a/gson/src/main/java/com/google/gson/JsonSerializationVisitor.java b/gson/src/main/java/com/google/gson/JsonSerializationVisitor.java
index e55bcc09..3a5fa043 100644
--- a/gson/src/main/java/com/google/gson/JsonSerializationVisitor.java
+++ b/gson/src/main/java/com/google/gson/JsonSerializationVisitor.java
@@ -82,7 +82,7 @@ final class JsonSerializationVisitor implements ObjectNavigator.Visitor {
   public void visitArrayField(Field f, Type typeOfF, Object obj) {
     if (isFieldNull(f, obj)) {
       if (serializeNulls) {
-        addChildAsElement(f, new JsonNull());
+        addChildAsElement(f, JsonNull.INSTANCE);
       }
     } else {
       Object array = getFieldValue(f, obj);
@@ -93,7 +93,7 @@ final class JsonSerializationVisitor implements ObjectNavigator.Visitor {
   public void visitCollectionField(Field f, Type typeOfF, Object obj) {
     if (isFieldNull(f, obj)) {
       if (serializeNulls) {
-        addChildAsElement(f, new JsonNull());
+        addChildAsElement(f, JsonNull.INSTANCE);
       }
     } else {
       if (typeOfF == null) {
@@ -120,7 +120,7 @@ final class JsonSerializationVisitor implements ObjectNavigator.Visitor {
   public void visitObjectField(Field f, Type typeOfF, Object obj) {
     if (isFieldNull(f, obj)) {
       if (serializeNulls) {
-        addChildAsElement(f, new JsonNull());
+        addChildAsElement(f, JsonNull.INSTANCE);
       }
     } else {
       Object fieldValue = getFieldValue(f, obj);
@@ -167,7 +167,7 @@ final class JsonSerializationVisitor implements ObjectNavigator.Visitor {
   public void visitPrimitiveField(Field f, Type typeOfF, Object obj) {    
     if (isFieldNull(f, obj)) {
       if (serializeNulls) {
-        addChildAsElement(f, new JsonNull());
+        addChildAsElement(f, JsonNull.INSTANCE);
       }      
     } else {
       TypeInfo typeInfo = new TypeInfo(typeOfF);
diff --git a/gson/src/main/javacc/JsonParser.jj b/gson/src/main/javacc/JsonParser.jj
index d6a97a65..3b10257d 100755
--- a/gson/src/main/javacc/JsonParser.jj
+++ b/gson/src/main/javacc/JsonParser.jj
@@ -72,7 +72,7 @@ private JsonObject JsonObject() :
 
 private JsonNull JsonNull() :
 {
-  JsonNull json = new JsonNull();
+  JsonNull json = JsonNull.INSTANCE;
 }
 {
   "null"