Add detailed logging for expression resolution

Introduce a logger to ObjectResolver and add detailed debug messages to capture placeholder expressions and their resolutions. This change helps in tracking the replacement process, improving traceability and debugging of document processing.

engine/src/main/java/pro/verron/officestamper/api/ObjectResolver.java

@@ -1,7 +1,9 @@
 package pro.verron.officestamper.api;
 
+import org.docx4j.TextUtils;
 import org.docx4j.openpackaging.packages.WordprocessingMLPackage;
 import org.docx4j.wml.R;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.lang.Nullable;
 
@@ -16,6 +18,8 @@
  */
 public interface ObjectResolver {
 
+    Logger LOGGER = LoggerFactory.getLogger(ObjectResolver.class);
+
     /**
      * Resolves the expression in the given document with the provided object.
      *
@@ -28,15 +32,15 @@ public interface ObjectResolver {
      *
      * @throws OfficeStamperException if no resolver is found for the object
      */
-    default R resolve(
-            DocxPart document,
-            Placeholder placeholder,
-            Object object
-    ) {
+    default R resolve(DocxPart document, Placeholder placeholder, Object object) {
         R resolution = resolve(document, placeholder.content(), object);
-        var msg = "Expression '{}' replaced by '{}' with resolver {}";
-        LoggerFactory.getLogger(ObjectResolver.class)
-                     .debug(msg, placeholder, resolution, this);
+        if (LOGGER.isDebugEnabled()) {
+            var message = "Expression '{}' replaced by '{}' with resolver {}";
+            var expression = placeholder.expression();
+            var text = TextUtils.getText(resolution);
+            var resolverName = getClass().getSimpleName();
+            LOGGER.debug(message, expression, text, resolverName);
+        }
         return resolution;
     }
 
@@ -54,23 +58,15 @@ default R resolve(
      *
      * @throws OfficeStamperException if no resolver is found for the object
      */
-    default R resolve(
-            DocxPart docxPart,
-            String expression,
-            Object object
-    ) {
+    default R resolve(DocxPart docxPart, String expression, Object object) {
         return resolve(docxPart.document(), expression, object);
     }
 
     /**
      * @deprecated replaced by {@link #resolve(DocxPart, String, Object)}
      */
     @Deprecated(since = "2.3", forRemoval = true)
-    default R resolve(
-            WordprocessingMLPackage document,
-            String expression,
-            Object object
-    ) {
+    default R resolve(WordprocessingMLPackage document, String expression, Object object) {
         throw new OfficeStamperException("Should not be called, only legacy implementation might still override this");
     }