Improve exception for deserializing static final field

Previously it would report "Unexpected IllegalAccessException occurred..." due to the uncaught IllegalAccessException.
google · Oct 18, 2022 · d72a9d1 · d72a9d1
1 parent 55bbdca
commit d72a9d1
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Showing 2 changed files with 26 additions and 0 deletions.
diff --git a/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java b/gson/src/main/java/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java
@@ -142,7 +142,12 @@ private ReflectiveTypeAdapterFactory.BoundField createBoundField(
       final Gson context, final Field field, final Method accessor, final String name,
       final TypeToken<?> fieldType, boolean serialize, boolean deserialize,
       final boolean blockInaccessible) {
+
     final boolean isPrimitive = Primitives.isPrimitive(fieldType.getRawType());
+
+    int modifiers = field.getModifiers();
+    final boolean isStaticFinalField = Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers);
+
     JsonAdapter annotation = field.getAnnotation(JsonAdapter.class);
     TypeAdapter<?> mapped = null;
     if (annotation != null) {
@@ -199,6 +204,11 @@ void readIntoField(JsonReader reader, Object target)
         if (fieldValue != null || !isPrimitive) {
           if (blockInaccessible) {
             checkAccessible(target, field);
+          } else if (isStaticFinalField) {
+            // Reflection does not permit setting value of `static final` field, even after calling `setAccessible`
+            // Handle this here to avoid causing IllegalAccessException when calling `Field.set`
+            String description = ReflectionHelper.getAccessibleObjectDescription(field, jsonAdapterPresent);
+            throw new JsonIOException("Cannot set value of 'static final' " + description);
           }
           field.set(target, fieldValue);
         }

diff --git a/gson/src/test/java/com/google/gson/functional/ObjectTest.java b/gson/src/test/java/com/google/gson/functional/ObjectTest.java
@@ -20,6 +20,7 @@
 import com.google.gson.GsonBuilder;
 import com.google.gson.InstanceCreator;
 import com.google.gson.JsonElement;
+import com.google.gson.JsonIOException;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
 import com.google.gson.JsonSerializationContext;
@@ -524,6 +525,9 @@ public void testStaticFieldSerialization() {
 
     String json = gson.toJson(new ClassWithStaticField());
     assertEquals("{\"s\":\"initial\"}", json);
+
+    json = gson.toJson(new ClassWithStaticFinalField());
+    assertEquals("{\"s\":\"initial\"}", json);
   }
 
   /**
@@ -550,9 +554,21 @@ public void testStaticFieldDeserialization() {
     } finally {
       ClassWithStaticField.s = oldValue;
     }
+
+    try {
+      gson.fromJson("{\"s\":\"custom\"}", ClassWithStaticFinalField.class);
+      fail();
+    } catch (JsonIOException e) {
+      assertEquals("Cannot set value of 'static final' field 'com.google.gson.functional.ObjectTest$ClassWithStaticFinalField#s'",
+          e.getMessage());
+    }
   }
 
   static class ClassWithStaticField {
     static String s = "initial";
   }
+
+  static class ClassWithStaticFinalField {
+    static final String s = "initial";
+  }
 }