refactor: replace size checks with isEmpty(), safely collapse redundant "if X == null" or "if X != null" checks

app/common/src/main/java/stirling/software/common/model/ApplicationProperties.java

@@ -433,19 +433,17 @@ public class ApplicationProperties {
         private List<String> languages;
 
         public String getAppName() {
-            return appName != null && appName.trim().length() > 0 ? appName : null;
+            return appName != null && !appName.trim().isEmpty() ? appName : null;
         }
 
         public String getHomeDescription() {
-            return homeDescription != null && homeDescription.trim().length() > 0
+            return homeDescription != null && !homeDescription.trim().isEmpty()
                     ? homeDescription
                     : null;
         }
 
         public String getAppNameNavbar() {
-            return appNameNavbar != null && appNameNavbar.trim().length() > 0
+            return appNameNavbar != null && !appNameNavbar.trim().isEmpty() ? appNameNavbar : null;
-                    ? appNameNavbar
-                    : null;
         }
     }
 

app/common/src/main/java/stirling/software/common/util/CustomHtmlSanitizer.java

@@ -28,7 +28,7 @@ public class CustomHtmlSanitizer {
             new AttributePolicy() {
                 @Override
                 public String apply(String elementName, String attributeName, String value) {
-                    if (value == null || value.trim().isEmpty()) {
+                    if (value.trim().isEmpty()) {
                         return null;
                     }
 

app/common/src/main/java/stirling/software/common/util/PDFToFile.java

@@ -74,7 +74,7 @@ public class PDFToFile {
         Path tempInputFile = null;
         Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
 
         try {
             tempInputFile = Files.createTempFile("input_", ".pdf");
@@ -167,7 +167,7 @@ public class PDFToFile {
         Path tempInputFile = null;
         Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
 
         try {
             // Save the uploaded file to a temporary location
@@ -230,7 +230,7 @@ public class PDFToFile {
         // Get the original PDF file name without the extension
         String originalPdfFileName = Filenames.toSimpleFileName(inputFile.getOriginalFilename());
 
-        if (originalPdfFileName == null || "".equals(originalPdfFileName.trim())) {
+        if (originalPdfFileName == null || originalPdfFileName.trim().isEmpty()) {
             originalPdfFileName = "output.pdf";
         }
         // Assume file is pdf if no extension
@@ -248,7 +248,7 @@ public class PDFToFile {
         Path tempInputFile = null;
         Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
 
         try {
             // Save the uploaded file to a temporary location

app/common/src/main/java/stirling/software/common/util/PdfUtils.java

@@ -122,7 +122,7 @@ public class PdfUtils {
     }
 
     public static boolean hasImagesOnPage(PDPage page) throws IOException {
-        return getAllImages(page.getResources()).size() > 0;
+        return !getAllImages(page.getResources()).isEmpty();
     }
 
     public static boolean hasTextOnPage(PDPage page, String phrase) throws IOException {

app/core/src/main/java/stirling/software/SPDF/config/AppUpdateService.java

@@ -26,7 +26,7 @@ class AppUpdateService {
     @Scope("request")
     public boolean shouldShow() {
         boolean showUpdate = applicationProperties.getSystem().isShowUpdate();
-        boolean showAdminResult = (showAdmin != null) ? showAdmin.getShowUpdateOnlyAdmins() : true;
+        boolean showAdminResult = showAdmin == null || showAdmin.getShowUpdateOnlyAdmins();
         return showUpdate && showAdminResult;
     }
 }

app/core/src/main/java/stirling/software/SPDF/config/CleanUrlInterceptor.java

@@ -64,7 +64,7 @@ public class CleanUrlInterceptor implements HandlerInterceptor {
                 // Construct new query string
                 StringBuilder newQueryString = new StringBuilder();
                 for (Map.Entry<String, String> entry : allowedParameters.entrySet()) {
-                    if (newQueryString.length() > 0) {
+                    if (!newQueryString.isEmpty()) {
                         newQueryString.append("&");
                     }
                     newQueryString.append(entry.getKey()).append("=").append(entry.getValue());

app/core/src/main/java/stirling/software/SPDF/config/ExternalAppDepConfig.java

@@ -100,7 +100,7 @@ public class ExternalAppDepConfig {
                             "Missing dependency: {} - Disabling group: {} (Affected features: {})",
                             command,
                             group,
-                            affectedFeatures != null && !affectedFeatures.isEmpty()
+                            !affectedFeatures.isEmpty()
                                     ? String.join(", ", affectedFeatures)
                                     : "unknown");
                 }

app/core/src/main/java/stirling/software/SPDF/controller/api/RearrangePagesPDFController.java

@@ -259,7 +259,7 @@ public class RearrangePagesPDFController {
             int totalPages = document.getNumberOfPages();
             List<Integer> newPageOrder;
             if (sortType != null
-                    && sortType.length() > 0
+                    && !sortType.isEmpty()
                     && !"custom".equals(sortType.toLowerCase())) {
                 newPageOrder = processSortTypes(sortType, totalPages, pageOrder);
             } else {

app/core/src/main/java/stirling/software/SPDF/controller/api/SplitPdfBySizeController.java

@@ -273,7 +273,7 @@ public class SplitPdfBySizeController {
         log.debug("Starting handleSplitByPageCount with pageCount={}", pageCount);
         int currentPageCount = 0;
         log.debug("Creating initial output document");
-        PDDocument currentDoc = null;
+        PDDocument currentDoc;
         try {
             currentDoc = pdfDocumentFactory.createNewDocumentBasedOnOldDocument(sourceDocument);
             log.debug("Successfully created initial output document");
@@ -387,7 +387,7 @@ public class SplitPdfBySizeController {
 
         for (int i = 0; i < documentCount; i++) {
             log.debug("Creating document {} of {}", i + 1, documentCount);
-            PDDocument currentDoc = null;
+            PDDocument currentDoc;
             try {
                 currentDoc = pdfDocumentFactory.createNewDocumentBasedOnOldDocument(sourceDocument);
                 log.debug("Successfully created document {} of {}", i + 1, documentCount);

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java

@@ -69,12 +69,11 @@ public class ConvertImgPDFController {
         Path tempFile = null;
         Path tempOutputDir = null;
         Path tempPdfPath = null;
-        byte[] result = null;
+        byte[] result;
         String[] pageOrderArr =
                 (pageNumbers != null && !pageNumbers.trim().isEmpty())
                         ? pageNumbers.split(",")
                         : new String[] {"all"};
-        ;
         try {
             // Load the input PDF
             byte[] newPdfBytes = rearrangePdfPages(file, pageOrderArr);
@@ -102,7 +101,7 @@ public class ConvertImgPDFController {
                             singleImage,
                             dpi,
                             filename);
-            if (result == null || result.length == 0) {
+            if (result.length == 0) {
                 log.error("resultant bytes for {} is null, error converting ", filename);
             }
             if ("webp".equalsIgnoreCase(imageFormat) && !CheckProgramInstall.isPythonAvailable()) {
@@ -159,7 +158,7 @@ public class ConvertImgPDFController {
                             "No WebP files were created. " + resultProcess.getMessages());
                 }
 
-                byte[] bodyBytes = new byte[0];
+                byte[] bodyBytes;
 
                 if (webpFiles.size() == 1) {
                     // Return the single WebP file directly
@@ -179,7 +178,7 @@ public class ConvertImgPDFController {
                 }
                 // Clean up the temporary files
                 Files.deleteIfExists(tempFile);
-                if (tempOutputDir != null) FileUtils.deleteDirectory(tempOutputDir.toFile());
+                FileUtils.deleteDirectory(tempOutputDir.toFile());
                 result = bodyBytes;
             }
 

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertOfficeController.java

@@ -88,7 +88,7 @@ public class ConvertOfficeController {
             return tempOutputFile.toFile();
         } finally {
             // Clean up the temporary files
-            if (tempInputFile != null) Files.deleteIfExists(tempInputFile);
+            Files.deleteIfExists(tempInputFile);
         }
     }
 

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertPDFToPDFA.java

@@ -123,7 +123,7 @@ public class ConvertPDFToPDFA {
                 preProcessedFile = preProcessHighlights(tempInputFile.toFile());
             }
             Set<String> missingFonts = new HashSet<>();
-            boolean needImgs = false;
+            boolean needImgs;
             try (PDDocument doc = Loader.loadPDF(preProcessedFile)) {
                 missingFonts = findUnembeddedFontNames(doc);
                 needImgs = (pdfaPart == 1) && hasTransparentImages(doc);
@@ -285,7 +285,7 @@ public class ConvertPDFToPDFA {
                 if (fontStream == null) continue;
 
                 try (InputStream in = fontStream.createInputStream()) {
-                    PDFont newFont = null;
+                    PDFont newFont;
                     try {
                         newFont = PDType0Font.load(baseDoc, in, false);
                     } catch (IOException e1) {

app/core/src/main/java/stirling/software/SPDF/controller/api/filters/FilterController.java

@@ -84,7 +84,7 @@ public class FilterController {
         PDDocument document = pdfDocumentFactory.load(inputFile);
         int actualPageCount = document.getNumberOfPages();
 
-        boolean valid = false;
+        boolean valid;
         // Perform the comparison
         switch (comparator) {
             case "Greater":
@@ -127,7 +127,7 @@ public class FilterController {
         PDRectangle standardSize = PdfUtils.textToPageSize(standardPageSize);
         float standardArea = standardSize.getWidth() * standardSize.getHeight();
 
-        boolean valid = false;
+        boolean valid;
         // Perform the comparison
         switch (comparator) {
             case "Greater":
@@ -160,7 +160,7 @@ public class FilterController {
         // Get the file size
         long actualFileSize = inputFile.getSize();
 
-        boolean valid = false;
+        boolean valid;
         // Perform the comparison
         switch (comparator) {
             case "Greater":
@@ -196,7 +196,7 @@ public class FilterController {
         // Get the rotation of the first page
         PDPage firstPage = document.getPage(0);
         int actualRotation = firstPage.getRotation();
-        boolean valid = false;
+        boolean valid;
         // Perform the comparison
         switch (comparator) {
             case "Greater":

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/AutoRenameController.java

@@ -75,7 +75,7 @@ public class AutoRenameController {
                     }
 
                     private void processLine() {
-                        if (lineBuilder.length() > 0 && lineCount < LINE_LIMIT) {
+                        if (!lineBuilder.isEmpty() && lineCount < LINE_LIMIT) {
                             lineInfos.add(new LineInfo(lineBuilder.toString(), maxFontSizeInLine));
                         }
                     }

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/AutoSplitPdfController.java

@@ -118,7 +118,7 @@ public class AutoSplitPdfController {
         PDDocument document = null;
         List<PDDocument> splitDocuments = new ArrayList<>();
         Path zipFile = null;
-        byte[] data = null;
+        byte[] data;
 
         try {
             document = pdfDocumentFactory.load(file.getInputStream());

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/CompressController.java

@@ -782,11 +782,8 @@ public class CompressController {
 
                     // Check if we can't increase the level further
                     if (newOptimizeLevel == optimizeLevel) {
-                        if (autoMode) {
+                        log.info("Maximum optimization level reached without meeting target size.");
-                            log.info(
+                        sizeMet = true;
-                                    "Maximum optimization level reached without meeting target size.");
-                            sizeMet = true;
-                        }
                     } else {
                         // Reset flags for next iteration with higher optimization level
                         imageCompressionApplied = false;
@@ -888,7 +885,7 @@ public class CompressController {
         command.add("-sOutputFile=" + gsOutputFile.toString());
         command.add(currentFile.toString());
 
-        ProcessExecutorResult returnCode = null;
+        ProcessExecutorResult returnCode;
         try {
             returnCode =
                     ProcessExecutor.getInstance(ProcessExecutor.Processes.GHOSTSCRIPT)

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java

@@ -69,7 +69,7 @@ public class ExtractImageScansController {
         List<String> images = new ArrayList<>();
 
         List<Path> tempImageFiles = new ArrayList<>();
-        Path tempInputFile = null;
+        Path tempInputFile;
         Path tempZipFile = null;
         List<Path> tempDirs = new ArrayList<>();
 
@@ -181,7 +181,7 @@ public class ExtractImageScansController {
                 return WebResponseUtils.bytesToWebResponse(
                         zipBytes, outputZipFilename, MediaType.APPLICATION_OCTET_STREAM);
             }
-            if (processedImageBytes.size() == 0) {
+            if (processedImageBytes.isEmpty()) {
                 throw new IllegalArgumentException("No images detected");
             } else {
 

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

@@ -143,7 +143,7 @@ public class MetadataController {
                 }
             }
         }
-        if (creationDate != null && creationDate.length() > 0) {
+        if (creationDate != null && !creationDate.isEmpty()) {
             Calendar creationDateCal = Calendar.getInstance();
             try {
                 creationDateCal.setTime(
@@ -155,7 +155,7 @@ public class MetadataController {
         } else {
             info.setCreationDate(null);
         }
-        if (modificationDate != null && modificationDate.length() > 0) {
+        if (modificationDate != null && !modificationDate.isEmpty()) {
             Calendar modificationDateCal = Calendar.getInstance();
             try {
                 modificationDateCal.setTime(

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/OCRController.java

@@ -126,7 +126,7 @@ public class OCRController {
             try {
                 // Use OCRmyPDF if available (no fallback - error if it fails)
                 if (isOcrMyPdfEnabled()) {
-                    if (sidecar != null && sidecar) {
+                    if (sidecar) {
                         sidecarTextFile = new TempFile(tempFileManager, ".txt");
                     }
 
@@ -165,7 +165,7 @@ public class OCRController {
                                         .replaceFirst("[.][^.]+$", "")
                                 + "_OCR.pdf";
 
-                if (sidecar != null && sidecar && sidecarTextFile != null) {
+                if (sidecar && sidecarTextFile != null) {
                     // Create a zip file containing both the PDF and the text file
                     String outputZipFilename =
                             Filenames.toSimpleFileName(inputFile.getOriginalFilename())
@@ -257,7 +257,7 @@ public class OCRController {
         if (cleanFinal != null && cleanFinal) {
             command.add("--clean-final");
         }
-        if (ocrType != null && !"".equals(ocrType)) {
+        if (ocrType != null && !ocrType.isEmpty()) {
             if ("skip-text".equals(ocrType)) {
                 command.add("--skip-text");
             } else if ("force-ocr".equals(ocrType)) {
@@ -338,7 +338,7 @@ public class OCRController {
 
                 for (int pageNum = 0; pageNum < pageCount; pageNum++) {
                     PDPage page = document.getPage(pageNum);
-                    boolean hasText = false;
+                    boolean hasText;
 
                     // Check for existing text
                     try (PDDocument tempDoc = new PDDocument()) {

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/StampController.java

@@ -183,7 +183,7 @@ public class StampController {
             float margin,
             String colorString) // Y override
             throws IOException {
-        String resourceDir = "";
+        String resourceDir;
         PDFont font = new PDType1Font(Standard14Fonts.FontName.HELVETICA);
         switch (alphabet) {
             case "arabic":
@@ -207,18 +207,16 @@ public class StampController {
                 break;
         }
 
-        if (!"".equals(resourceDir)) {
+        ClassPathResource classPathResource = new ClassPathResource(resourceDir);
-            ClassPathResource classPathResource = new ClassPathResource(resourceDir);
+        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
-            String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
 
-            // Use TempFile with try-with-resources for automatic cleanup
+        // Use TempFile with try-with-resources for automatic cleanup
-            try (TempFile tempFileWrapper = new TempFile(tempFileManager, fileExtension)) {
+        try (TempFile tempFileWrapper = new TempFile(tempFileManager, fileExtension)) {
-                File tempFile = tempFileWrapper.getFile();
+            File tempFile = tempFileWrapper.getFile();
-                try (InputStream is = classPathResource.getInputStream();
+            try (InputStream is = classPathResource.getInputStream();
-                        FileOutputStream os = new FileOutputStream(tempFile)) {
+                    FileOutputStream os = new FileOutputStream(tempFile)) {
-                    IOUtils.copy(is, os);
+                IOUtils.copy(is, os);
-                    font = PDType0Font.load(document, tempFile);
+                font = PDType0Font.load(document, tempFile);
-                }
             }
         }
 

app/core/src/main/java/stirling/software/SPDF/controller/api/pipeline/PipelineController.java

@@ -68,7 +68,7 @@ public class PipelineController {
 
         try {
             List<Resource> inputFiles = processor.generateInputFiles(files);
-            if (inputFiles == null || inputFiles.size() == 0) {
+            if (inputFiles == null || inputFiles.isEmpty()) {
                 return null;
             }
             PipelineResult result = processor.runPipelineAgainstFiles(inputFiles, config);

app/core/src/main/java/stirling/software/SPDF/controller/api/pipeline/PipelineDirectoryProcessor.java

@@ -115,7 +115,7 @@ public class PipelineDirectoryProcessor {
         log.info("Handling directory: {}", dir);
         Path processingDir = createProcessingDirectory(dir);
         Optional<Path> jsonFileOptional = findJsonFile(dir);
-        if (!jsonFileOptional.isPresent()) {
+        if (jsonFileOptional.isEmpty()) {
             log.warn("No .JSON settings file found. No processing will happen for dir {}.", dir);
             return;
         }
@@ -150,7 +150,7 @@ public class PipelineDirectoryProcessor {
         for (PipelineOperation operation : config.getOperations()) {
             validateOperation(operation);
             File[] files = collectFilesForProcessing(dir, jsonFile, operation);
-            if (files == null || files.length == 0) {
+            if (files.length == 0) {
                 log.debug("No files detected for {} ", dir);
                 return;
             }

app/core/src/main/java/stirling/software/SPDF/controller/api/security/GetInfoOnPDF.java

@@ -119,7 +119,7 @@ public class GetInfoOnPDF {
         if (!ap.canModifyAnnotations()) restrictedPermissions.add("annotation modification");
         if (!ap.canPrint()) restrictedPermissions.add("printing");
 
-        if (restrictedPermissions.size() > 0) {
+        if (!restrictedPermissions.isEmpty()) {
             summaryData.set("restrictedPermissions", restrictedPermissions);
             summaryData.put("restrictedPermissionsCount", restrictedPermissions.size());
         }
@@ -193,7 +193,7 @@ public class GetInfoOnPDF {
     public ResponseEntity<byte[]> getPdfInfo(@ModelAttribute PDFFile request) throws IOException {
         MultipartFile inputFile = request.getFileInput();
         boolean readonly = true;
-        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile, readonly); ) {
+        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile, readonly)) {
             ObjectMapper objectMapper = new ObjectMapper();
             ObjectNode jsonOutput = objectMapper.createObjectNode();
 
@@ -249,7 +249,6 @@ public class GetInfoOnPDF {
             docInfoNode.put("PDF version", pdfBoxDoc.getVersion());
             docInfoNode.put("Trapped", info.getTrapped());
             docInfoNode.put("Page Mode", getPageModeDescription(pageMode));
-            ;
 
             PDAcroForm acroForm = pdfBoxDoc.getDocumentCatalog().getAcroForm();
 
@@ -263,7 +262,7 @@ public class GetInfoOnPDF {
 
             // Generate structured summary data about PDF characteristics
             ObjectNode summaryData = generatePDFSummaryData(pdfBoxDoc);
-            if (summaryData != null && summaryData.size() > 0) {
+            if (summaryData != null && !summaryData.isEmpty()) {
                 jsonOutput.set("SummaryData", summaryData);
             }
 
@@ -788,7 +787,7 @@ public class GetInfoOnPDF {
 
                         // Recursively explore child elements
                         ArrayNode childElements = exploreStructureTree(structureElement.getKids());
-                        if (childElements.size() > 0) {
+                        if (!childElements.isEmpty()) {
                             elementNode.set("Children", childElements);
                         }
                     }

app/core/src/main/java/stirling/software/SPDF/controller/api/security/SanitizeController.java

@@ -176,11 +176,9 @@ public class SanitizeController {
     private void sanitizeLinks(PDDocument document) throws IOException {
         for (PDPage page : document.getPages()) {
             for (PDAnnotation annotation : page.getAnnotations()) {
-                if (annotation != null && annotation instanceof PDAnnotationLink linkAnnotation) {
+                if (annotation instanceof PDAnnotationLink linkAnnotation) {
                     PDAction action = linkAnnotation.getAction();
-                    if (action != null
+                    if ((action instanceof PDActionLaunch || action instanceof PDActionURI)) {
-                            && (action instanceof PDActionLaunch
-                                    || action instanceof PDActionURI)) {
                         linkAnnotation.setAction(null);
                     }
                 }

app/core/src/main/java/stirling/software/SPDF/controller/api/security/WatermarkController.java

@@ -191,17 +191,15 @@ public class WatermarkController {
                 break;
         }
 
-        if (!"".equals(resourceDir)) {
+        ClassPathResource classPathResource = new ClassPathResource(resourceDir);
-            ClassPathResource classPathResource = new ClassPathResource(resourceDir);
+        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
-            String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
+        File tempFile = Files.createTempFile("NotoSansFont", fileExtension).toFile();
-            File tempFile = Files.createTempFile("NotoSansFont", fileExtension).toFile();
+        try (InputStream is = classPathResource.getInputStream();
-            try (InputStream is = classPathResource.getInputStream();
+                FileOutputStream os = new FileOutputStream(tempFile)) {
-                    FileOutputStream os = new FileOutputStream(tempFile)) {
+            IOUtils.copy(is, os);
-                IOUtils.copy(is, os);
+            font = PDType0Font.load(document, tempFile);
-                font = PDType0Font.load(document, tempFile);
+        } finally {
-            } finally {
+            Files.deleteIfExists(tempFile.toPath());
-                if (tempFile != null) Files.deleteIfExists(tempFile.toPath());
-            }
         }
 
         contentStream.setFont(font, fontSize);

app/core/src/main/java/stirling/software/SPDF/controller/web/GeneralWebController.java

@@ -75,7 +75,7 @@ public class GeneralWebController {
                             new ObjectMapper()
                                     .readValue(config, new TypeReference<Map<String, Object>>() {});
                     String name = (String) jsonContent.get("name");
-                    if (name == null || name.length() < 1) {
+                    if (name == null || name.isEmpty()) {
                         String filename =
                                 jsonFiles
                                         .get(pipelineConfigs.indexOf(config))
@@ -92,7 +92,7 @@ public class GeneralWebController {
                 log.error("exception", e);
             }
         }
-        if (pipelineConfigsWithNames.size() == 0) {
+        if (pipelineConfigsWithNames.isEmpty()) {
             Map<String, String> configWithName = new HashMap<>();
             configWithName.put("json", "");
             configWithName.put("name", "No preloaded configs found");

app/core/src/main/java/stirling/software/SPDF/service/ApiDocService.java

@@ -52,7 +52,7 @@ public class ApiDocService {
     }
 
     public List<String> getExtensionTypes(boolean output, String operationName) {
-        if (outputToFileTypes.size() == 0) {
+        if (outputToFileTypes.isEmpty()) {
             outputToFileTypes.put("PDF", Arrays.asList("pdf"));
             outputToFileTypes.put(
                     "IMAGE",
@@ -74,7 +74,7 @@ public class ApiDocService {
                     "BOOK", Arrays.asList("epub", "mobi", "azw3", "fb2", "txt", "docx"));
             // type.
         }
-        if (apiDocsJsonRootNode == null || apiDocumentation.size() == 0) {
+        if (apiDocsJsonRootNode == null || apiDocumentation.isEmpty()) {
             loadApiDocumentation();
         }
         if (!apiDocumentation.containsKey(operationName)) {
@@ -138,7 +138,7 @@ public class ApiDocService {
     }
 
     public boolean isValidOperation(String operationName, Map<String, Object> parameters) {
-        if (apiDocumentation.size() == 0) {
+        if (apiDocumentation.isEmpty()) {
             loadApiDocumentation();
         }
         if (!apiDocumentation.containsKey(operationName)) {
@@ -149,7 +149,7 @@ public class ApiDocService {
     }
 
     public boolean isMultiInput(String operationName) {
-        if (apiDocsJsonRootNode == null || apiDocumentation.size() == 0) {
+        if (apiDocsJsonRootNode == null || apiDocumentation.isEmpty()) {
             loadApiDocumentation();
         }
         if (!apiDocumentation.containsKey(operationName)) {

app/core/src/main/java/stirling/software/SPDF/service/MetricsAggregatorService.java

@@ -31,7 +31,7 @@ public class MetricsAggregatorService {
     public void aggregateAndSendMetrics() {
         Map<String, Object> metrics = new HashMap<>();
 
-        final boolean validateGetEndpoints = endpointInspector.getValidGetEndpoints().size() != 0;
+        final boolean validateGetEndpoints = !endpointInspector.getValidGetEndpoints().isEmpty();
         Search.in(meterRegistry)
                 .name("http.requests")
                 .counters()