Merge pull request #4334 from square/jw.primitive-tags.2025-04-01

Support primitive types for `@Tag`

Author: squarejesse

CHANGELOG.md

@@ -16,7 +16,7 @@
 
 **Fixed**
 
- - Nothing yet!
+ - Primitive types used with `@Tag` now work by storing the value boxed with the boxed class as the key.
 
 
 ## [2.11.0] - 2024-03-28

retrofit/java-test/src/test/java/retrofit2/RequestFactoryTest.java

@@ -3330,6 +3330,19 @@ Call<ResponseBody> method(@Tag String tag) {
     assertThat(request.tag(String.class)).isEqualTo("tagValue");
   }
 
+  @Test
+  public void tagPrimitive() {
+    class Example {
+      @GET("/")
+      Call<ResponseBody> method(@Tag long timestamp) {
+        return null;
+      }
+    }
+
+    Request request = buildRequest(Example.class, 42L);
+    assertThat(request.tag(Long.class)).isEqualTo(42L);
+  }
+
   @Test
   public void tagGeneric() {
     class Example {

retrofit/src/main/java/retrofit2/RequestFactory.java

@@ -800,7 +800,7 @@ private ParameterHandler<?> parseParameterAnnotation(
       } else if (annotation instanceof Tag) {
         validateResolvableType(p, type);
 
-        Class<?> tagType = Utils.getRawType(type);
+        Class<?> tagType = boxIfPrimitive(Utils.getRawType(type));
         for (int i = p - 1; i >= 0; i--) {
           ParameterHandler<?> otherHandler = parameterHandlers[i];
           if (otherHandler instanceof ParameterHandler.Tag

retrofit/src/main/java/retrofit2/http/Tag.java

@@ -31,7 +31,9 @@
  * </code></pre>
  *
  * Tag arguments may be {@code null} which will omit them from the request. Passing a parameterized
- * type such as {@code List<String>} will use the raw type (i.e., {@code List.class}) as the key.
+ * type will use the raw type as the key (e.g., {@code List<String>} uses {@code List.class}).
+ * Primitive types will be boxed and stored using the boxed type
+ * (e.g., {@code long} uses {@code Long.class}).
  * Duplicate tag types are not allowed.
  */
 @Documented