Fix for #377 and minor fixes found by Sonar lint (#388)

pf4j/src/main/java/org/pf4j/PropertiesPluginDescriptorFinder.java

@@ -75,17 +75,21 @@ public class PropertiesPluginDescriptorFinder implements PluginDescriptorFinder
             throw new PluginRuntimeException("Cannot find the properties path");
         }
 
+        Properties properties = new Properties();
+        try {
             log.debug("Lookup plugin descriptor in '{}'", propertiesPath);
             if (Files.notExists(propertiesPath)) {
                 throw new PluginRuntimeException("Cannot find '{}' path", propertiesPath);
             }
 
-        Properties properties = new Properties();
             try (InputStream input = Files.newInputStream(propertiesPath)) {
                 properties.load(input);
             } catch (IOException e) {
                 throw new PluginRuntimeException(e);
             }
+        } finally {
+            FileUtils.closePath(propertiesPath);
+        }
 
         return properties;
     }

pf4j/src/main/java/org/pf4j/ServiceProviderExtensionFinder.java

@@ -121,13 +121,18 @@ public class ServiceProviderExtensionFinder extends AbstractExtensionFinder {
 
     private void collectExtensions(URL url, Set<String> bucket) throws URISyntaxException, IOException {
         Path extensionPath;
+
         if (url.toURI().getScheme().equals("jar")) {
             extensionPath = FileUtils.getPath(url.toURI(), EXTENSIONS_RESOURCE);
         } else {
             extensionPath = Paths.get(url.toURI());
         }
 
+        try {
             bucket.addAll(readExtensions(extensionPath));
+        } finally {
+            FileUtils.closePath(extensionPath);
+        }
     }
 
     private Set<String> readExtensions(Path extensionPath) throws IOException {

pf4j/src/main/java/org/pf4j/processor/ExtensionStorage.java

@@ -82,8 +82,7 @@ public abstract class ExtensionStorage {
     }
 
     public static void read(Reader reader, Set<String> entries) throws IOException {
-        BufferedReader bufferedReader = new BufferedReader(reader);
-
+        try (BufferedReader bufferedReader = new BufferedReader(reader)) {
             String line;
             while ((line = bufferedReader.readLine()) != null) {
                 line = COMMENT.matcher(line).replaceFirst("");
@@ -92,8 +91,7 @@ public abstract class ExtensionStorage {
                     entries.add(line);
                 }
             }
-
-        bufferedReader.close();
+        }
     }
 
 }

pf4j/src/main/java/org/pf4j/processor/LegacyExtensionStorage.java

@@ -65,7 +65,7 @@ public class LegacyExtensionStorage extends ExtensionStorage {
     public void write(Map<String, Set<String>> extensions) {
         try {
             FileObject file = getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", EXTENSIONS_RESOURCE);
-            BufferedWriter writer = new BufferedWriter(file.openWriter());
+            try (BufferedWriter writer = new BufferedWriter(file.openWriter())) {
                 writer.write("# Generated by PF4J"); // write header
                 writer.newLine();
                 for (Map.Entry<String, Set<String>> entry : extensions.entrySet()) {
@@ -74,8 +74,7 @@ public class LegacyExtensionStorage extends ExtensionStorage {
                         writer.newLine();
                     }
                 }
-
-            writer.close();
+            }
         } catch (FileNotFoundException e) {
             // it's the first time, create the file
         } catch (FilerException e) {

pf4j/src/main/java/org/pf4j/processor/ServiceProviderExtensionStorage.java

@@ -70,7 +70,7 @@ public class ServiceProviderExtensionStorage extends ExtensionStorage {
             try {
                 FileObject file = getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", EXTENSIONS_RESOURCE
                     + "/" + extensionPoint);
-                BufferedWriter writer = new BufferedWriter(file.openWriter());
+                try (BufferedWriter writer = new BufferedWriter(file.openWriter())) {
                     // write header
                     writer.write("# Generated by PF4J"); // write header
                     writer.newLine();
@@ -82,7 +82,7 @@ public class ServiceProviderExtensionStorage extends ExtensionStorage {
                         }
                         writer.newLine();
                     }
-                writer.close();
+                }
             } catch (FileNotFoundException e) {
                 // it's the first time, create the file
             } catch (FilerException e) {

pf4j/src/main/java/org/pf4j/util/FileUtils.java

@@ -42,12 +42,10 @@ import java.util.List;
 /**
  * @author Decebal Suiu
  */
-public class FileUtils {
+public final class FileUtils {
 
     private static final Logger log = LoggerFactory.getLogger(FileUtils.class);
 
-    private static final boolean IS_WINDOWS_OS = System.getProperty("os.name").startsWith("Windows");
-
     public static List<String> readLines(Path path, boolean ignoreComments) throws IOException {
         File file = path.toFile();
         if (!file.isFile()) {
@@ -163,7 +161,9 @@ public class FileUtils {
 
         try {
             Files.delete(path);
-        } catch (IOException ignored) { }
+        } catch (IOException ignored) {
+            // ignored
+        }
     }
 
     /**
@@ -224,7 +224,7 @@ public class FileUtils {
             // transformation for Windows OS
             pathString = StringUtils.addStart(pathString.replace("\\", "/"), "/");
             // space is replaced with %20
-            pathString = pathString.replaceAll(" ","%20");
+            pathString = pathString.replace(" ","%20");
             uri = URI.create("jar:file:" + pathString);
         }
 
@@ -232,14 +232,17 @@ public class FileUtils {
     }
 
     public static Path getPath(URI uri, String first, String... more) throws IOException {
-        FileSystem fileSystem = getFileSystem(uri);
-        Path path = fileSystem.getPath(first, more);
-        if (IS_WINDOWS_OS && "jar".equals(uri.getScheme())) {
-            // it's a ZipFileSystem
-            fileSystem.close();
+        return getFileSystem(uri).getPath(first, more);
     }
 
-        return path;
+    public static void closePath(Path path) {
+        if (path != null) {
+            try {
+                path.getFileSystem().close();
+            } catch (Exception e) {
+                // close silently
+            }
+        }
     }
 
     public static Path findFile(Path directoryPath, String fileName) {
@@ -270,4 +273,6 @@ public class FileUtils {
         }
     }
 
+    private FileUtils() {
+    }
 }

pf4j/src/test/java/org/pf4j/plugin/PluginJar.java

@@ -146,8 +146,8 @@ public class PluginJar {
 
         public PluginJar build() throws IOException {
             Manifest manifest = createManifest();
-            try (OutputStream outputStream = new FileOutputStream(path.toFile())) {
-                JarOutputStream jarOutputStream = new JarOutputStream(outputStream, manifest);
+            try (OutputStream outputStream = new FileOutputStream(path.toFile());
+                 JarOutputStream jarOutputStream = new JarOutputStream(outputStream, manifest)) {
                 if (!extensions.isEmpty()) {
                     // add extensions.idx
                     JarEntry jarEntry = new JarEntry("META-INF/extensions.idx");
@@ -163,7 +163,6 @@ public class PluginJar {
                         jarOutputStream.closeEntry();
                     }
                 }
-                jarOutputStream.close();
             }
 
             return new PluginJar(this);