diff --git a/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/parser/GoogleParser.java b/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/parser/GoogleParser.java
index 0f680550..68c40028 100644
--- a/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/parser/GoogleParser.java
+++ b/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/parser/GoogleParser.java
@@ -35,6 +35,7 @@ public class GoogleParser implements BookParser {
     private static final Pattern WHITESPACE_PATTERN = Pattern.compile("\\s+");
     private static final Pattern SPECIAL_CHARACTERS_PATTERN = Pattern.compile("[.,\\-\\[\\]{}()!@#$%^&*_=+|~`<>?/\";:]");
     private final ObjectMapper objectMapper;
+    private final HttpClient httpClient = HttpClient.newHttpClient();
     private static final String GOOGLE_BOOKS_API_URL = "https://www.googleapis.com/books/v1/volumes";
 
     @Override
@@ -61,13 +62,12 @@ public class GoogleParser implements BookParser {
 
             log.info("Google Books API URL (ISBN): {}", uri);
 
-            HttpClient client = HttpClient.newHttpClient();
             HttpRequest request = HttpRequest.newBuilder()
                     .uri(uri)
                     .GET()
                     .build();
 
-            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+            HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
 
             if (response.statusCode() == 200) {
                 return parseGoogleBooksApiResponse(response.body());
@@ -91,13 +91,12 @@ public class GoogleParser implements BookParser {
 
             log.info("Google Books API URL: {}", uri);
 
-            HttpClient client = HttpClient.newHttpClient();
             HttpRequest request = HttpRequest.newBuilder()
                     .uri(uri)
                     .GET()
                     .build();
 
-            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+            HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
 
             if (response.statusCode() == 200) {
                 return parseGoogleBooksApiResponse(response.body());
diff --git a/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/writer/EpubMetadataWriter.java b/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/writer/EpubMetadataWriter.java
index 0bfe22f5..8ced7225 100644
--- a/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/writer/EpubMetadataWriter.java
+++ b/booklore-api/src/main/java/com/adityachandel/booklore/service/metadata/writer/EpubMetadataWriter.java
@@ -55,8 +55,9 @@ public class EpubMetadataWriter implements MetadataWriter {
         Path tempDir = null;
         try {
             tempDir = Files.createTempDirectory("epub_edit_" + UUID.randomUUID());
-            ZipFile zipFile = new ZipFile(epubFile);
-            zipFile.extractAll(tempDir.toString());
+            try (ZipFile zipFile = new ZipFile(epubFile)) {
+                zipFile.extractAll(tempDir.toString());
+            }
 
             File opfFile = findOpfFile(tempDir.toFile());
             if (opfFile == null) {
@@ -171,7 +172,9 @@ public class EpubMetadataWriter implements MetadataWriter {
                 transformer.transform(new DOMSource(opfDoc), new StreamResult(opfFile));
 
                 File tempEpub = new File(epubFile.getParentFile(), epubFile.getName() + ".tmp");
-                addFolderContentsToZip(new ZipFile(tempEpub), tempDir.toFile(), tempDir.toFile());
+                try (ZipFile tempZipFile = new ZipFile(tempEpub)) {
+                    addFolderContentsToZip(tempZipFile, tempDir.toFile(), tempDir.toFile());
+                }
 
                 if (!epubFile.delete()) throw new IOException("Could not delete original EPUB");
                 if (!tempEpub.renameTo(epubFile)) throw new IOException("Could not rename temp EPUB");
@@ -260,7 +263,9 @@ public class EpubMetadataWriter implements MetadataWriter {
         try {
             File epubFile = new File(bookEntity.getFullFilePath().toUri());
             tempDir = Files.createTempDirectory("epub_cover_" + UUID.randomUUID());
-            new ZipFile(epubFile).extractAll(tempDir.toString());
+            try (ZipFile zipFile = new ZipFile(epubFile)) {
+                zipFile.extractAll(tempDir.toString());
+            }
 
             File opfFile = findOpfFile(tempDir.toFile());
             if (opfFile == null) {
@@ -282,7 +287,9 @@ public class EpubMetadataWriter implements MetadataWriter {
             transformer.transform(new DOMSource(opfDoc), new StreamResult(opfFile));
 
             File tempEpub = new File(epubFile.getParentFile(), epubFile.getName() + ".tmp");
-            addFolderContentsToZip(new ZipFile(tempEpub), tempDir.toFile(), tempDir.toFile());
+            try (ZipFile tempZipFile = new ZipFile(tempEpub)) {
+                addFolderContentsToZip(tempZipFile, tempDir.toFile(), tempDir.toFile());
+            }
 
             if (!epubFile.delete()) throw new IOException("Could not delete original EPUB");
             if (!tempEpub.renameTo(epubFile)) throw new IOException("Could not rename temp EPUB");
@@ -308,7 +315,9 @@ public class EpubMetadataWriter implements MetadataWriter {
         try {
             File epubFile = new File(bookEntity.getFullFilePath().toUri());
             tempDir = Files.createTempDirectory("epub_cover_url_" + UUID.randomUUID());
-            new ZipFile(epubFile).extractAll(tempDir.toString());
+            try (ZipFile zipFile = new ZipFile(epubFile)) {
+                zipFile.extractAll(tempDir.toString());
+            }
 
             File opfFile = findOpfFile(tempDir.toFile());
             if (opfFile == null) {
@@ -335,7 +344,9 @@ public class EpubMetadataWriter implements MetadataWriter {
             transformer.transform(new DOMSource(opfDoc), new StreamResult(opfFile));
 
             File tempEpub = new File(epubFile.getParentFile(), epubFile.getName() + ".tmp");
-            addFolderContentsToZip(new ZipFile(tempEpub), tempDir.toFile(), tempDir.toFile());
+            try (ZipFile tempZipFile = new ZipFile(tempEpub)) {
+                addFolderContentsToZip(tempZipFile, tempDir.toFile(), tempDir.toFile());
+            }
 
             if (!epubFile.delete()) throw new IOException("Could not delete original EPUB");
             if (!tempEpub.renameTo(epubFile)) throw new IOException("Could not rename temp EPUB");
diff --git a/booklore-api/src/main/java/com/adityachandel/booklore/service/migration/AppMigrationService.java b/booklore-api/src/main/java/com/adityachandel/booklore/service/migration/AppMigrationService.java
index 078689c2..3989ad1f 100644
--- a/booklore-api/src/main/java/com/adityachandel/booklore/service/migration/AppMigrationService.java
+++ b/booklore-api/src/main/java/com/adityachandel/booklore/service/migration/AppMigrationService.java
@@ -127,46 +127,48 @@ public class AppMigrationService {
 
         try {
             if (Files.exists(thumbsDir)) {
-                Files.walk(thumbsDir)
-                        .filter(Files::isRegularFile)
-                        .forEach(path -> {
-                            try {
-                                // Load original image
-                                BufferedImage originalImage = ImageIO.read(path.toFile());
-                                if (originalImage == null) {
-                                    log.warn("Skipping non-image file: {}", path);
-                                    return;
+                try (var stream = Files.walk(thumbsDir)) {
+                    stream.filter(Files::isRegularFile)
+                            .forEach(path -> {
+                                try {
+                                    // Load original image
+                                    BufferedImage originalImage = ImageIO.read(path.toFile());
+                                    if (originalImage == null) {
+                                        log.warn("Skipping non-image file: {}", path);
+                                        return;
+                                    }
+
+                                    // Extract bookId from folder structure
+                                    Path relative = thumbsDir.relativize(path);       // e.g., "11/f.jpg"
+                                    String bookId = relative.getParent().toString();  // "11"
+
+                                    Path bookDir = imagesDir.resolve(bookId);
+                                    Files.createDirectories(bookDir);
+
+                                    // Copy original to cover.jpg
+                                    Path coverFile = bookDir.resolve("cover.jpg");
+                                    ImageIO.write(originalImage, "jpg", coverFile.toFile());
+
+                                    // Resize and save thumbnail.jpg
+                                    BufferedImage resized = fileService.resizeImage(originalImage, 250, 350);
+                                    Path thumbnailFile = bookDir.resolve("thumbnail.jpg");
+                                    ImageIO.write(resized, "jpg", thumbnailFile.toFile());
+
+                                    log.debug("Processed book {}: cover={} thumbnail={}", bookId, coverFile, thumbnailFile);
+                                } catch (IOException e) {
+                                    log.error("Error processing file {}", path, e);
+                                    throw new UncheckedIOException(e);
                                 }
-
-                                // Extract bookId from folder structure
-                                Path relative = thumbsDir.relativize(path);       // e.g., "11/f.jpg"
-                                String bookId = relative.getParent().toString();  // "11"
-
-                                Path bookDir = imagesDir.resolve(bookId);
-                                Files.createDirectories(bookDir);
-
-                                // Copy original to cover.jpg
-                                Path coverFile = bookDir.resolve("cover.jpg");
-                                ImageIO.write(originalImage, "jpg", coverFile.toFile());
-
-                                // Resize and save thumbnail.jpg
-                                BufferedImage resized = fileService.resizeImage(originalImage, 250, 350);
-                                Path thumbnailFile = bookDir.resolve("thumbnail.jpg");
-                                ImageIO.write(resized, "jpg", thumbnailFile.toFile());
-
-                                log.debug("Processed book {}: cover={} thumbnail={}", bookId, coverFile, thumbnailFile);
-                            } catch (IOException e) {
-                                log.error("Error processing file {}", path, e);
-                                throw new UncheckedIOException(e);
-                            }
-                        });
+                            });
+                }
 
                 // Delete old thumbs directory
                 log.info("Deleting old thumbs directory: {}", thumbsDir);
-                Files.walk(thumbsDir)
-                        .sorted(Comparator.reverseOrder())
-                        .map(Path::toFile)
-                        .forEach(File::delete);
+                try (var stream = Files.walk(thumbsDir)) {
+                    stream.sorted(Comparator.reverseOrder())
+                            .map(Path::toFile)
+                            .forEach(File::delete);
+                }
             }
         } catch (IOException e) {
             log.error("Error during migration populateCoversAndResizeThumbnails", e);