chore\!: Use Jackson for all JSON deserialization in codecs

Simplify JacksonCodec and JsonCodec by using Jackson for all type
deserialization instead of custom primitive type handling. This provides
consistent behavior and better error messages but removes lenient type
conversions (e.g., boolean to integer).

Update tests to match Jackson's stricter type conversion behavior and
rename misleading test methods.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Artur-

flow-server/src/main/java/com/vaadin/flow/internal/JacksonCodec.java

@@ -254,20 +254,11 @@ public static <T> T decodeAs(JsonNode json, Class<T> type) {
         if (json.getNodeType() == JsonNodeType.NULL && !type.isPrimitive()) {
             return null;
         }
-        Class<?> convertedType = ReflectTools.convertPrimitiveType(type);
-        if (type == String.class) {
-            return type.cast(json.asText(""));
-        } else if (convertedType == Boolean.class) {
-            return (T) convertedType
-                    .cast(Boolean.valueOf(json.asBoolean(false)));
-        } else if (convertedType == Double.class) {
-            return (T) convertedType.cast(Double.valueOf(json.asDouble(0.0)));
-        } else if (convertedType == Integer.class) {
-            return (T) convertedType.cast(Integer.valueOf(json.asInt(0)));
-        } else if (JsonNode.class.isAssignableFrom(type)) {
+        if (JsonNode.class.isAssignableFrom(type)) {
             return type.cast(json);
         } else {
-            // Try to deserialize as a bean using Jackson
+            // Use Jackson for all deserialization - it handles primitives,
+            // strings, and complex objects uniformly
             try {
                 return JacksonUtils.getMapper().treeToValue(json, type);
             } catch (Exception e) {

flow-server/src/main/java/com/vaadin/flow/internal/JsonCodec.java

@@ -245,21 +245,11 @@ public static <T> T decodeAs(JsonValue json, Class<T> type) {
         if (json.getType() == JsonType.NULL && !type.isPrimitive()) {
             return null;
         }
-        Class<?> convertedType = ReflectTools.convertPrimitiveType(type);
-        if (type == String.class) {
-            return type.cast(json.asString());
-        } else if (convertedType == Boolean.class) {
-            return (T) convertedType.cast(Boolean.valueOf(json.asBoolean()));
-        } else if (convertedType == Double.class) {
-            return (T) convertedType.cast(Double.valueOf(json.asNumber()));
-        } else if (convertedType == Integer.class) {
-            return (T) convertedType
-                    .cast(Integer.valueOf((int) json.asNumber()));
-        } else if (JsonValue.class.isAssignableFrom(type)) {
+        if (JsonValue.class.isAssignableFrom(type)) {
             return type.cast(json);
         } else {
-            // Try to deserialize as a bean using Jackson via JsonValue
-            // conversion
+            // Use Jackson for all deserialization via JsonValue conversion -
+            // it handles primitives, strings, and complex objects uniformly
             try {
                 // Convert JsonValue to JsonNode for Jackson deserialization
                 JsonNode jsonNode = JacksonUtils.getMapper()

flow-server/src/test/java/com/vaadin/flow/internal/JacksonCodecTest.java

@@ -152,36 +152,31 @@ private static void assertJsonEquals(JsonNode expected, JsonNode actual) {
     public void decodeAs_booleanJson() {
         JsonNode json = objectMapper.valueToTree(true);
         Assert.assertTrue(JacksonCodec.decodeAs(json, Boolean.class));
-        Assert.assertEquals("true", JacksonCodec.decodeAs(json, String.class));
-        Assert.assertEquals(Integer.valueOf(0),
-                JacksonCodec.decodeAs(json, Integer.class));
-        Assert.assertEquals(Double.valueOf(0.0),
-                JacksonCodec.decodeAs(json, Double.class));
         Assert.assertEquals(json, JacksonCodec.decodeAs(json, JsonNode.class));
     }
 
     @Test
     public void decodeAs_stringJson() {
         JsonNode json = objectMapper.valueToTree("Test123 String\n !%");
-        Assert.assertFalse(JacksonCodec.decodeAs(json, Boolean.class));
         Assert.assertEquals("Test123 String\n !%",
                 JacksonCodec.decodeAs(json, String.class));
-        Assert.assertEquals(Integer.valueOf(0),
-                JacksonCodec.decodeAs(json, Integer.class));
-        Assert.assertFalse(JacksonCodec.decodeAs(json, Double.class).isNaN());
         Assert.assertEquals(json, JacksonCodec.decodeAs(json, JsonNode.class));
     }
 
     @Test
     public void decodeAs_numberJson() {
-        JsonNode json = objectMapper.valueToTree(15.7);
-        Assert.assertFalse(JacksonCodec.decodeAs(json, Boolean.class));
-        Assert.assertEquals("15.7", JacksonCodec.decodeAs(json, String.class));
+        // Test integer
+        JsonNode intJson = objectMapper.valueToTree(15);
         Assert.assertEquals(Integer.valueOf(15),
-                JacksonCodec.decodeAs(json, Integer.class));
+                JacksonCodec.decodeAs(intJson, Integer.class));
+        Assert.assertEquals(Double.valueOf(15.0),
+                JacksonCodec.decodeAs(intJson, Double.class));
+        
+        // Test double
+        JsonNode doubleJson = objectMapper.valueToTree(15.7);
         Assert.assertEquals(Double.valueOf(15.7),
-                JacksonCodec.decodeAs(json, Double.class));
-        Assert.assertEquals(json, JacksonCodec.decodeAs(json, JsonNode.class));
+                JacksonCodec.decodeAs(doubleJson, Double.class));
+        Assert.assertEquals(doubleJson, JacksonCodec.decodeAs(doubleJson, JsonNode.class));
     }
 
     @Test
@@ -198,34 +193,7 @@ public void decodeAs_nullJson() {
     public void decodeAs_jsonValue() {
         ObjectNode json = objectMapper.createObjectNode();
         json.put("foo", "bar");
-        Assert.assertEquals("", JacksonCodec.decodeAs(json, String.class));
         Assert.assertEquals(json, JacksonCodec.decodeAs(json, JsonNode.class));
-        // boolean
-        Assert.assertFalse(JacksonCodec.decodeAs(json, Boolean.class));
-        Assert.assertNull(
-                JacksonCodec.decodeAs(objectMapper.nullNode(), Boolean.class));
-        Assert.assertFalse(JacksonCodec.decodeAs(json, boolean.class));
-        Assert.assertFalse(
-                JacksonCodec.decodeAs(objectMapper.nullNode(), boolean.class));
-        // integer
-        Assert.assertEquals(Integer.valueOf(0),
-                JacksonCodec.decodeAs(json, Integer.class));
-        Assert.assertNull(
-                JacksonCodec.decodeAs(objectMapper.nullNode(), Integer.class));
-        Assert.assertEquals(Integer.valueOf(0),
-                JacksonCodec.decodeAs(json, int.class));
-        Assert.assertEquals(Integer.valueOf(0),
-                JacksonCodec.decodeAs(objectMapper.nullNode(), int.class));
-        // double
-        Assert.assertNull(
-                JacksonCodec.decodeAs(objectMapper.nullNode(), Double.class));
-        Assert.assertEquals(Double.valueOf(0.0),
-                JacksonCodec.decodeAs(json, Double.class));
-        Assert.assertEquals(Double.valueOf(0.0),
-                JacksonCodec.decodeAs(json, double.class));
-        Assert.assertEquals(0.0d,
-                JacksonCodec.decodeAs(objectMapper.nullNode(), double.class),
-                0.0001d);
     }
 
     @Test(expected = ClassCastException.class)