Fix deserialization failure in Change Metadata (#2382)

* Fix deserialization failure from String to Map

Fix deserialization failure from String to Map that caused the following exception:
Resolved [org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public org.springframework.http.ResponseEntity<byte[]> stirling.software.SPDF.controller.api.misc.MetadataController.metadata(stirling.software.SPDF.model.api.misc.MetadataRequest) throws java.io.IOException: [Field error in object 'metadataRequest' on field 'allRequestParams': rejected value [{"customKey1" : "YourCustomKey", "customKeyValue1", "YourCustomValue"}]; codes [typeMismatch.metadataRequest.allRequestParams,typeMismatch.allRequestParams,typeMismatch.java.util.Map,typeMismatch];

* Fix form binding for dynamic Map entries in Change Metadata

- Implemented support for dynamic key-value inputs in Change Metadata form using proper `name` attributes for Map (`allRequestParams`) binding.
- Fix form binding for dynamic Map (`allRequestParams`) entries in Change Metadata as the `allRequestParams` (Map name) was being sent as an empty map.

src/main/java/stirling/software/SPDF/controller/api/misc/MetadataController.java

@@ -14,6 +14,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.WebDataBinder;
+import org.springframework.web.bind.annotation.InitBinder;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -26,6 +28,7 @@
 
 import stirling.software.SPDF.model.api.misc.MetadataRequest;
 import stirling.software.SPDF.utils.WebResponseUtils;
+import stirling.software.SPDF.utils.propertyeditor.StringToMapPropertyEditor;
 
 @RestController
 @RequestMapping("/api/v1/misc")
@@ -44,6 +47,11 @@ private String checkUndefined(String entry) {
         return entry;
     }
 
+    @InitBinder
+    public void initBinder(WebDataBinder binder) {
+        binder.registerCustomEditor(Map.class, "allRequestParams", new StringToMapPropertyEditor());
+    }
+
     @PostMapping(consumes = "multipart/form-data", value = "/update-metadata")
     @Operation(
             summary = "Update metadata of a PDF file",

src/main/java/stirling/software/SPDF/utils/propertyeditor/StringToMapPropertyEditor.java

@@ -0,0 +1,26 @@
+package stirling.software.SPDF.utils.propertyeditor;
+
+import java.beans.PropertyEditorSupport;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class StringToMapPropertyEditor extends PropertyEditorSupport {
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    public void setAsText(String text) throws IllegalArgumentException {
+        try {
+            TypeReference<HashMap<String, String>> typeRef =
+                    new TypeReference<HashMap<String, String>>() {};
+            Map<String, String> map = objectMapper.readValue(text, typeRef);
+            setValue(map);
+        } catch (Exception e) {
+            throw new IllegalArgumentException(
+                    "Failed to convert java.lang.String to java.util.Map");
+        }
+    }
+}

src/main/resources/templates/misc/change-metadata.html

@@ -164,13 +164,13 @@ <h3 th:text="#{changeMetadata.selectText.4}"></h3>
                     keyInput.type = "text";
                     keyInput.placeholder = 'Key';
                     keyInput.className = "form-control";
-                    keyInput.name = "customKey" + count;
+                    keyInput.name = `allRequestParams[customKey${count}]`;
 
                     const valueInput = document.createElement("input");
                     valueInput.type = "text";
                     valueInput.placeholder = 'Value';
                     valueInput.className = "form-control";
-                    valueInput.name = "customValue" + count;
+                    valueInput.name = `allRequestParams[customValue${count}]`;
                     count = count + 1;
 
                     const formGroup = document.createElement("div");