Refactor Path Handling (#3041)

# Description of Changes

Please provide a summary of the changes, including:

What was changed:

- Refactored path constructions in multiple classes (e.g.,
SPDFApplication.java, InstallationPathConfig.java,
RuntimePathConfig.java) to use Java NIO’s Paths.get() and Path.of()
instead of manual string concatenation.


Why the change was made:

- To improve code readability, maintainability, and robustness by
leveraging modern Java NIO utilities.
- To ensure better portability across different operating systems by
avoiding hardcoded file separators.


Challenges encountered:

- Maintaining backward compatibility while transitioning from manual
string concatenation to using Paths for file path construction.
- Ensuring that the refactored path resolution works consistently across
all supported environments (Windows, macOS, Linux, and Docker).

@Frooodle can you check the docker path `/.dockerenv`?

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [x] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

src/main/java/stirling/software/SPDF/SPDFApplication.java

@@ -83,18 +83,17 @@ public class SPDFApplication {
         Map<String, String> propertyFiles = new HashMap<>();
 
         // External config files
-        log.info("Settings file: {}", InstallationPathConfig.getSettingsPath());
-        if (Files.exists(Paths.get(InstallationPathConfig.getSettingsPath()))) {
-            propertyFiles.put(
-                    "spring.config.additional-location",
-                    "file:" + InstallationPathConfig.getSettingsPath());
+        String settingsPath = InstallationPathConfig.getSettingsPath();
+        log.info("Settings file: {}", settingsPath);
+        if (Files.exists(Paths.get(settingsPath))) {
+            propertyFiles.put("spring.config.additional-location", "file:" + settingsPath);
         } else {
-            log.warn(
-                    "External configuration file '{}' does not exist.",
-                    InstallationPathConfig.getSettingsPath());
+            log.warn("External configuration file '{}' does not exist.", settingsPath);
         }
 
-        if (Files.exists(Paths.get(InstallationPathConfig.getCustomSettingsPath()))) {
+        String customSettingsPath = InstallationPathConfig.getCustomSettingsPath();
+        log.info("Custom settings file: {}", customSettingsPath);
+        if (Files.exists(Paths.get(customSettingsPath))) {
             String existingLocation =
                     propertyFiles.getOrDefault("spring.config.additional-location", "");
             if (!existingLocation.isEmpty()) {
@@ -102,11 +101,9 @@ public class SPDFApplication {
             }
             propertyFiles.put(
                     "spring.config.additional-location",
-                    existingLocation + "file:" + InstallationPathConfig.getCustomSettingsPath());
+                    existingLocation + "file:" + customSettingsPath);
         } else {
-            log.warn(
-                    "Custom configuration file '{}' does not exist.",
-                    InstallationPathConfig.getCustomSettingsPath());
+            log.warn("Custom configuration file '{}' does not exist.", customSettingsPath);
         }
         Properties finalProps = new Properties();
 
@@ -128,7 +125,7 @@ public class SPDFApplication {
         try {
             Files.createDirectories(Path.of(InstallationPathConfig.getTemplatesPath()));
             Files.createDirectories(Path.of(InstallationPathConfig.getStaticPath()));
-        } catch (Exception e) {
+        } catch (IOException e) {
             log.error("Error creating directories: {}", e.getMessage());
         }
 

src/main/java/stirling/software/SPDF/config/InstallationPathConfig.java

@@ -1,6 +1,7 @@
 package stirling.software.SPDF.config;
 
 import java.io.File;
+import java.nio.file.Paths;
 
 import lombok.extern.slf4j.Slf4j;
 
@@ -46,26 +47,29 @@ public class InstallationPathConfig {
         if (Boolean.parseBoolean(System.getProperty("STIRLING_PDF_DESKTOP_UI", "false"))) {
             String os = System.getProperty("os.name").toLowerCase();
             if (os.contains("win")) {
-                return System.getenv("APPDATA") + File.separator + "Stirling-PDF" + File.separator;
+                return Paths.get(
+                                        System.getenv("APPDATA"), // parent path
+                                        "Stirling-PDF")
+                                .toString()
+                        + File.separator;
             } else if (os.contains("mac")) {
-                return System.getProperty("user.home")
-                        + File.separator
-                        + "Library"
-                        + File.separator
-                        + "Application Support"
-                        + File.separator
-                        + "Stirling-PDF"
+                return Paths.get(
+                                        System.getProperty("user.home"),
+                                        "Library",
+                                        "Application Support",
+                                        "Stirling-PDF")
+                                .toString()
                         + File.separator;
             } else {
-                return System.getProperty("user.home")
-                        + File.separator
-                        + ".config"
-                        + File.separator
-                        + "Stirling-PDF"
+                return Paths.get(
+                                        System.getProperty("user.home"), // parent path
+                                        ".config",
+                                        "Stirling-PDF")
+                                .toString()
                         + File.separator;
             }
         }
-        return "./";
+        return "." + File.separator;
     }
 
     public static String getPath() {

src/main/java/stirling/software/SPDF/config/RuntimePathConfig.java

@@ -1,8 +1,7 @@
 package stirling.software.SPDF.config;
 
-import java.io.File;
 import java.nio.file.Files;
-import java.nio.file.Paths;
+import java.nio.file.Path;
 
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.context.annotation.Configuration;
@@ -33,52 +32,48 @@ public class RuntimePathConfig {
         this.properties = properties;
         this.basePath = InstallationPathConfig.getPath();
 
-        String pipelinePath = basePath + "pipeline" + File.separator;
-        String watchedFoldersPath = pipelinePath + "watchedFolders" + File.separator;
-        String finishedFoldersPath = pipelinePath + "finishedFolders" + File.separator;
-        String webUiConfigsPath = pipelinePath + "defaultWebUIConfigs" + File.separator;
+        this.pipelinePath = Path.of(basePath, "pipeline").toString();
+        String defaultWatchedFolders = Path.of(this.pipelinePath, "watchedFolders").toString();
+        String defaultFinishedFolders = Path.of(this.pipelinePath, "finishedFolders").toString();
+        String defaultWebUIConfigs = Path.of(this.pipelinePath, "defaultWebUIConfigs").toString();
 
         Pipeline pipeline = properties.getSystem().getCustomPaths().getPipeline();
-        if (pipeline != null) {
-            if (!StringUtils.isEmpty(pipeline.getWatchedFoldersDir())) {
-                watchedFoldersPath = pipeline.getWatchedFoldersDir();
-            }
-            if (!StringUtils.isEmpty(pipeline.getFinishedFoldersDir())) {
-                finishedFoldersPath = pipeline.getFinishedFoldersDir();
-            }
-            if (!StringUtils.isEmpty(pipeline.getWebUIConfigsDir())) {
-                webUiConfigsPath = pipeline.getWebUIConfigsDir();
-            }
-        }
 
-        this.pipelinePath = pipelinePath;
-        this.pipelineWatchedFoldersPath = watchedFoldersPath;
-        this.pipelineFinishedFoldersPath = finishedFoldersPath;
-        this.pipelineDefaultWebUiConfigs = webUiConfigsPath;
+        this.pipelineWatchedFoldersPath =
+                resolvePath(
+                        defaultWatchedFolders,
+                        pipeline != null ? pipeline.getWatchedFoldersDir() : null);
+        this.pipelineFinishedFoldersPath =
+                resolvePath(
+                        defaultFinishedFolders,
+                        pipeline != null ? pipeline.getFinishedFoldersDir() : null);
+        this.pipelineDefaultWebUiConfigs =
+                resolvePath(
+                        defaultWebUIConfigs,
+                        pipeline != null ? pipeline.getWebUIConfigsDir() : null);
 
         boolean isDocker = isRunningInDocker();
 
         // Initialize Operation paths
-        String weasyPrintPath = isDocker ? "/opt/venv/bin/weasyprint" : "weasyprint";
-        String unoConvertPath = isDocker ? "/opt/venv/bin/unoconvert" : "unoconvert";
+        String defaultWeasyPrintPath = isDocker ? "/opt/venv/bin/weasyprint" : "weasyprint";
+        String defaultUnoConvertPath = isDocker ? "/opt/venv/bin/unoconvert" : "unoconvert";
 
-        // Check for custom operation paths
         Operations operations = properties.getSystem().getCustomPaths().getOperations();
-        if (operations != null) {
-            if (!StringUtils.isEmpty(operations.getWeasyprint())) {
-                weasyPrintPath = operations.getWeasyprint();
-            }
-            if (!StringUtils.isEmpty(operations.getUnoconvert())) {
-                unoConvertPath = operations.getUnoconvert();
-            }
-        }
+        this.weasyPrintPath =
+                resolvePath(
+                        defaultWeasyPrintPath,
+                        operations != null ? operations.getWeasyprint() : null);
+        this.unoConvertPath =
+                resolvePath(
+                        defaultUnoConvertPath,
+                        operations != null ? operations.getUnoconvert() : null);
+    }
 
-        // Assign operations final fields
-        this.weasyPrintPath = weasyPrintPath;
-        this.unoConvertPath = unoConvertPath;
+    private String resolvePath(String defaultPath, String customPath) {
+        return StringUtils.isNotBlank(customPath) ? customPath : defaultPath;
     }
 
     private boolean isRunningInDocker() {
-        return Files.exists(Paths.get("/.dockerenv"));
+        return Files.exists(Path.of("/.dockerenv"));
     }
 }

src/main/java/stirling/software/SPDF/config/security/database/DatabaseConfig.java

@@ -1,7 +1,5 @@
 package stirling.software.SPDF.config.security.database;
 
-import java.io.File;
-
 import javax.sql.DataSource;
 
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -37,8 +35,8 @@ public class DatabaseConfig {
         DATASOURCE_DEFAULT_URL =
                 "jdbc:h2:file:"
                         + InstallationPathConfig.getConfigPath()
-                        + File.separator
                         + "stirling-pdf-DB-2.3.232;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE";
+        log.debug("Database URL: {}", DATASOURCE_DEFAULT_URL);
         this.applicationProperties = applicationProperties;
         this.runningEE = runningEE;
     }

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

@@ -230,7 +230,11 @@ public class GeneralWebController {
         // Extract font names from external directory
         fontNames.addAll(
                 getFontNamesFromLocation(
-                        "file:" + InstallationPathConfig.getStaticPath() + "fonts/*"));
+                        "file:"
+                                + InstallationPathConfig.getStaticPath()
+                                + "fonts"
+                                + File.separator
+                                + "*"));
         return fontNames;
     }
 

src/main/java/stirling/software/SPDF/utils/FileMonitor.java

@@ -49,7 +49,8 @@ public class FileMonitor {
         this.pathFilter = pathFilter;
         this.readyForProcessingFiles = ConcurrentHashMap.newKeySet();
         this.watchService = FileSystems.getDefault().newWatchService();
-        this.rootDir = Path.of(runtimePathConfig.getPipelineWatchedFoldersPath()).toAbsolutePath();
+        log.info("Monitoring directory: {}", runtimePathConfig.getPipelineWatchedFoldersPath());
+        this.rootDir = Path.of(runtimePathConfig.getPipelineWatchedFoldersPath());
     }
 
     private boolean shouldNotProcess(Path path) {