From d347128e6fbfbe307cfbfde384235f43c80045f1 Mon Sep 17 00:00:00 2001
From: Inderjeet Singh <inder123@gmail.com>
Date: Sat, 25 Jun 2011 20:04:14 +0000
Subject: [PATCH] Implemented support for serializing objects of type Bar<Foo>
 without the need to specify their type explicitly in toJson method.

---
 .../google/gson/ReflectingFieldNavigator.java   | 17 ++++++++++++++++-
 .../gson/functional/RawSerializationTest.java   | 12 +++++-------
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/gson/src/main/java/com/google/gson/ReflectingFieldNavigator.java b/gson/src/main/java/com/google/gson/ReflectingFieldNavigator.java
index eee28e61..0e88b77f 100644
--- a/gson/src/main/java/com/google/gson/ReflectingFieldNavigator.java
+++ b/gson/src/main/java/com/google/gson/ReflectingFieldNavigator.java
@@ -18,6 +18,7 @@ package com.google.gson;
 import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Field;
 import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -59,7 +60,7 @@ final class ReflectingFieldNavigator {
           || exclusionStrategy.shouldSkipClass(fieldAttributes.getDeclaredClass())) {
         continue; // skip
       }
-      Type resolvedTypeOfField = fieldAttributes.getResolvedType();
+      Type resolvedTypeOfField = getMoreSpecificType(fieldAttributes.getResolvedType(), obj, fieldAttributes);
       boolean visitedWithCustomHandler =
         visitor.visitFieldUsingCustomHandler(fieldAttributes, resolvedTypeOfField, obj);
       if (!visitedWithCustomHandler) {
@@ -72,6 +73,20 @@ final class ReflectingFieldNavigator {
     }
   }
 
+  @SuppressWarnings("unchecked")
+  private Type getMoreSpecificType(Type type, Object obj, FieldAttributes fieldAttributes) {
+    try {
+      if (obj != null && (Object.class == type || type instanceof TypeVariable)) {
+        Object fieldValue = fieldAttributes.get(obj);
+        if (fieldValue != null) {
+          type = fieldValue.getClass();
+        }
+      }
+    } catch (IllegalAccessException e) {
+    }
+    return type;
+  }
+
   private List<FieldAttributes> getAllFields(Type type, Type declaredType) {
     List<FieldAttributes> fields = fieldsCache.getElement(type);
     if (fields == null) {
diff --git a/gson/src/test/java/com/google/gson/functional/RawSerializationTest.java b/gson/src/test/java/com/google/gson/functional/RawSerializationTest.java
index da5e93d6..de0322bf 100644
--- a/gson/src/test/java/com/google/gson/functional/RawSerializationTest.java
+++ b/gson/src/test/java/com/google/gson/functional/RawSerializationTest.java
@@ -18,7 +18,6 @@ package com.google.gson.functional;
 import java.util.Arrays;
 import java.util.Collection;
 
-import junit.framework.AssertionFailedError;
 import junit.framework.TestCase;
 
 import com.google.gson.Gson;
@@ -54,12 +53,11 @@ public class RawSerializationTest extends TestCase {
   public void testParameterizedObject() {
     Bar<Foo> bar = new Bar<Foo>(new Foo(1));
     String expectedJson = "{\"t\":{\"b\":1}}";
-    try {
-      String json = gson.toJson(bar);
-      assertEquals(expectedJson, json);
-    } catch (AssertionFailedError expected) {
-    }
-    String json = gson.toJson(bar, new TypeToken<Bar<Foo>>(){}.getType());
+    // Ensure that serialization works without specifying the type explicitly
+    String json = gson.toJson(bar);
+    assertEquals(expectedJson, json);
+    // Ensure that serialization also works when the type is specified explicitly
+    json = gson.toJson(bar, new TypeToken<Bar<Foo>>(){}.getType());
     assertEquals(expectedJson, json);
   }