Simplify the condition to invoke resolveCodec method in AnnotationRed…

…isCodecResolver #1149

This adds a 'methodHasAtMostOneCodec' utility method to check whether a
CommandMethod has at most one codec

Original pull request: #1150.

src/main/java/io/lettuce/core/dynamic/codec/AnnotationRedisCodecResolver.java

@@ -33,9 +33,9 @@
  * determine a {@link RedisCodec} that is able to handle all involved types.
  *
  * @author Mark Paluch
- * @since 5.0
  * @see Key
  * @see Value
+ * @since 5.0
  */
 public class AnnotationRedisCodecResolver implements RedisCodecResolver {
 
@@ -71,18 +71,23 @@ public AnnotationRedisCodecResolver(List<RedisCodec<?, ?>> codecs) {
             return codecs.get(0);
         }
 
-        if ((keyTypes.size() == 1 && (valueTypes.isEmpty() || valueTypes.size() == 1))
-                || (valueTypes.size() == 1 && (keyTypes.isEmpty() || keyTypes.size() == 1))) {
-
-            RedisCodec<?, ?> codec = resolveCodec(keyTypes, valueTypes);
-            if (codec != null) {
-                return codec;
+        if (methodHasAtMostOneCodec(keyTypes, valueTypes)) {
+            RedisCodec<?, ?> resolvedCodec = resolveCodec(keyTypes, valueTypes);
+            if (resolvedCodec != null) {
+                return resolvedCodec;
             }
         }
 
         throw new IllegalStateException(String.format("Cannot resolve Codec for method %s", commandMethod.getMethod()));
     }
 
+    private boolean methodHasAtMostOneCodec(Set<Class<?>> keyTypes, Set<Class<?>> valueTypes) {
+        final int keyTypesSize = keyTypes.size();
+        final int valueTypesSize = valueTypes.size();
+
+        return keyTypesSize == 1 && valueTypesSize <= 1 || valueTypesSize == 1 && keyTypesSize <= 1;
+    }
+
     private Voted<RedisCodec<?, ?>> voteForTypeMajority(CommandMethod commandMethod) {
 
         List<Voted<RedisCodec<?, ?>>> votes = codecs.stream().map(redisCodec -> new Voted<RedisCodec<?, ?>>(redisCodec, 0))
@@ -139,12 +144,10 @@ private static void vote(List<Voted<RedisCodec<?, ?>>> votes, Parameter paramete
     }
 
     private RedisCodec<?, ?> resolveCodec(Set<Class<?>> keyTypes, Set<Class<?>> valueTypes) {
-
         Class<?> keyType = keyTypes.isEmpty() ? null : keyTypes.iterator().next();
         Class<?> valueType = valueTypes.isEmpty() ? null : valueTypes.iterator().next();
 
         for (RedisCodec<?, ?> codec : codecs) {
-
             ClassTypeInformation<?> typeInformation = ClassTypeInformation.from(codec.getClass());
             TypeInformation<?> keyTypeArgument = typeInformation.getTypeArgument(RedisCodec.class, 0);
             TypeInformation<?> valueTypeArgument = typeInformation.getTypeArgument(RedisCodec.class, 1);

src/test/java/io/lettuce/core/dynamic/codec/AnnotationRedisCodecResolverUnitTests.java

@@ -89,12 +89,17 @@ void shouldResolveHintedByteArrayValue() {
     }
 
     @Test
-    void resolutionShouldFail() {
-
+    void resolutionOfMethodWithMixedTypesShouldFail() {
         Method method = ReflectionUtils.findMethod(CommandMethods.class, "mixedTypes", String.class, byte[].class);
         assertThatThrownBy(() -> resolve(method)).isInstanceOf(IllegalStateException. class);
     }
 
+    @Test
+    void resolutionOfMethodWithMixedCodecsShouldFail() {
+        Method method = ReflectionUtils.findMethod(CommandMethods.class, "mixedCodecs",  String.class, byte[].class, String.class);
+        assertThatThrownBy(() -> resolve(method)).isInstanceOf(IllegalStateException. class);
+    }
+
     @Test
     void shouldDiscoverCodecTypesFromWrappers() {
 
@@ -129,6 +134,8 @@ private static interface CommandMethods {
 
         String mixedTypes(@Key String key, @Value byte[] value);
 
+        String mixedCodecs(@Key String key1, @Key byte[] key2, @Value String value);
+
         String withWrappers(@Value Range<String> range, @Value io.lettuce.core.Value<Number> value);
 
         String withMap(Map<Integer, String> map);