Update PDF reader example

05-document-readers/document-readers-pdf-ollama/src/main/java/com/thomasvitale/ai/spring/ChatService.java

@@ -1,5 +1,7 @@
 package com.thomasvitale.ai.spring;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.ai.chat.ChatClient;
 import org.springframework.ai.chat.messages.AssistantMessage;
 import org.springframework.ai.chat.messages.UserMessage;
@@ -12,11 +14,16 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
+import static org.springframework.ai.reader.pdf.PagePdfDocumentReader.*;
+
 @Service
 class ChatService {
 
+    private static final Logger log = LoggerFactory.getLogger(ChatService.class);
+
     private final ChatClient chatClient;
     private final SimpleVectorStore vectorStore;
 
@@ -37,6 +44,7 @@ Answer questions given the context information below (DOCUMENTS section) and no
                 """);
 
         List<Document> similarDocuments = vectorStore.similaritySearch(SearchRequest.query(message).withTopK(2));
+        logDocumentMetadata(similarDocuments);
         String documents = similarDocuments.stream().map(Document::getContent).collect(Collectors.joining(System.lineSeparator()));
 
         Map<String,Object> model = Map.of("documents", documents);
@@ -49,4 +57,16 @@ Answer questions given the context information below (DOCUMENTS section) and no
         return chatResponse.getResult().getOutput();
     }
 
+    private void logDocumentMetadata(List<Document> documents) {
+        log.info("Similar documents retrieved to answer your question:");
+        documents.forEach(document -> {
+            var metadata = Map.of(
+                    "fileName", document.getMetadata().get(METADATA_FILE_NAME),
+                    "startPageNumber", document.getMetadata().get(METADATA_START_PAGE_NUMBER),
+                    "endPageNumber", Objects.requireNonNullElse(document.getMetadata().get(METADATA_END_PAGE_NUMBER), "-")
+            );
+            log.info("Metadata: " + metadata);
+        });
+    }
+
 }