fix: remove indexFieldMap entry by field key, not running counter

fesod-sheet/src/main/java/org/apache/fesod/sheet/util/ClassUtils.java

@@ -364,7 +364,11 @@ private static FieldCache doDeclaredFields(Class<?> clazz, ConfigurationHolder c
             // The current field needs to be ignored
             if (writeHolder.ignore(field.getFieldName(), entry.getKey())) {
                 ignoreSet.add(field.getFieldName());
-                indexFieldMap.remove(index);
+                // indexFieldMap is keyed by the field's explicit @ExcelProperty(index), which for
+                // explicit-index fields equals the sortedFieldMap position (entry.getKey()); remove
+                // by that key, not the running counter, otherwise an unrelated explicit-index entry
+                // is dropped and the ignored field's entry may survive.
+                indexFieldMap.remove(key);
             } else {
                 // Mandatory sorted fields
                 if (indexFieldMap.containsKey(key)) {

fesod-sheet/src/test/java/org/apache/fesod/sheet/util/ClassUtilsTest.java

@@ -202,6 +202,29 @@ void test_declaredFields_WriteHolder_exclude() {
         Assertions.assertTrue(hasAge);
     }
 
+    @Test
+    void test_declaredFields_WriteHolder_exclude_preservesUnrelatedExplicitIndex() {
+        // Excluding a field that has NO explicit @ExcelProperty(index) (here "email",
+        // which uses order=10) must not perturb indexFieldMap, which only holds fields
+        // that DO carry an explicit index (ComplexEntity: id->0, name->2).
+        Mockito.when(globalConfiguration.getFiledCacheLocation()).thenReturn(CacheLocationEnum.NONE);
+
+        Mockito.when(writeHolder.excludeColumnFieldNames()).thenReturn(Collections.singleton("email"));
+        Mockito.when(writeHolder.ignore(Mockito.anyString(), Mockito.anyInt())).thenReturn(false);
+        Mockito.when(writeHolder.ignore(Mockito.eq("email"), Mockito.anyInt())).thenReturn(true);
+
+        FieldCache fieldCache = ClassUtils.declaredFields(ComplexEntity.class, writeHolder);
+
+        Map<Integer, FieldWrapper> indexFieldMap = fieldCache.getIndexFieldMap();
+        // id (@ExcelProperty(index = 0)) and name (index = 2) must still be present and
+        // bound to their explicit indices; the ignored field was never in this map.
+        Assertions.assertTrue(indexFieldMap.containsKey(0), "explicit index 0 (id) must remain");
+        Assertions.assertEquals("id", indexFieldMap.get(0).getFieldName());
+        Assertions.assertTrue(indexFieldMap.containsKey(2), "explicit index 2 (name) must remain");
+        Assertions.assertEquals("name", indexFieldMap.get(2).getFieldName());
+        Assertions.assertFalse(indexFieldMap.values().stream().anyMatch(f -> "email".equals(f.getFieldName())));
+    }
+
     @Test
     void test_declaredFields_resort() {
         Mockito.when(globalConfiguration.getFiledCacheLocation()).thenReturn(CacheLocationEnum.NONE);