better archive support

src/main/java/cz/kamma/kfmanager/service/FileOperations.java

@@ -735,7 +735,7 @@ public class FileOperations {
     public static byte[] readFileFromArchive(File archive, String entryPath) throws IOException {
         String name = archive.getName().toLowerCase();
         try {
-            if (name.endsWith(".zip") || name.endsWith(".jar")) {
+            if (name.endsWith(".car") || name.endsWith(".zip") || name.endsWith(".jar")) {
                 try (ZipInputStream zis = new ZipInputStream(new FileInputStream(archive))) {
                     ZipEntry entry;
                     while ((entry = zis.getNextEntry()) != null) {
@@ -817,14 +817,138 @@ public class FileOperations {
     public static boolean isArchiveFile(String filename) {
         if (filename == null) return false;
         String n = filename.toLowerCase();
-        return n.endsWith(".war") || n.endsWith(".zip") || n.endsWith(".jar") || n.endsWith(".tar") || n.endsWith(".tar.gz") || n.endsWith(".tgz") || n.endsWith(".7z") || n.endsWith(".rar");
+        return n.endsWith(".car") || n.endsWith(".war") || n.endsWith(".zip") || n.endsWith(".jar") || n.endsWith(".tar") || n.endsWith(".tar.gz") || n.endsWith(".tgz") || n.endsWith(".7z") || n.endsWith(".rar");
+    }
+
+    /**
+     * Checks if a file can be opened as an archive by actually attempting to read it.
+     * This method does NOT rely on file extension - it always tries to actually
+     * read and parse the file as an archive to verify its contents.
+     */
+    public static boolean canOpenAsArchive(File file) {
+        if (file == null || !file.exists() || !file.isFile()) {
+            return false;
+        }
+
+        // Always try to detect format by actually reading the file content
+        // This works for any file regardless of extension
+        return tryDetectArchiveFormat(file);
+    }
+
+    /**
+     * Attempts to detect the archive format by trying to read the file.
+     * Returns true if the file can be opened as any supported archive format.
+     */
+    private static boolean tryDetectArchiveFormat(File file) {
+        try {
+            String name = file.getName().toLowerCase();
+
+            // Try ZIP (includes .car, .zip, .jar, .war, and any file with zip magic)
+            if (name.endsWith(".car") || name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war")) {
+                try (ZipInputStream zis = new ZipInputStream(new FileInputStream(file))) {
+                    ZipEntry entry = zis.getNextEntry();
+                    if (entry != null) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid zip
+                }
+            } else {
+                // Try ZIP for unknown extensions (zip files without extension)
+                try (ZipInputStream zis = new ZipInputStream(new FileInputStream(file))) {
+                    ZipEntry entry = zis.getNextEntry();
+                    if (entry != null) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid zip
+                }
+            }
+
+            // Try 7z
+            if (name.endsWith(".7z")) {
+                try (SevenZFile szf = new SevenZFile(file)) {
+                    SevenZArchiveEntry entry = szf.getNextEntry();
+                    if (entry != null) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid 7z
+                }
+            } else {
+                // Try 7z for unknown extensions
+                try (SevenZFile szf = new SevenZFile(file)) {
+                    SevenZArchiveEntry entry = szf.getNextEntry();
+                    if (entry != null) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid 7z
+                }
+            }
+
+            // Try RAR
+            if (name.endsWith(".rar")) {
+                try (com.github.junrar.Archive rar = new com.github.junrar.Archive(file)) {
+                    if (rar.getFileHeaders().size() > 0) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid rar
+                }
+            } else {
+                // Try RAR for unknown extensions
+                try (com.github.junrar.Archive rar = new com.github.junrar.Archive(file)) {
+                    if (rar.getFileHeaders().size() > 0) {
+                        return true;
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid rar
+                }
+            }
+
+            // Try TAR/TAR.GZ
+            if (name.endsWith(".tar") || name.endsWith(".tar.gz") || name.endsWith(".tgz")) {
+                try {
+                    InputStream is = new FileInputStream(file);
+                    if (name.endsWith(".gz") || name.endsWith(".tgz")) {
+                        is = new org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream(is);
+                    }
+                    try (org.apache.commons.compress.archivers.tar.TarArchiveInputStream tais = new org.apache.commons.compress.archivers.tar.TarArchiveInputStream(is)) {
+                        org.apache.commons.compress.archivers.tar.TarArchiveEntry entry = tais.getNextTarEntry();
+                        if (entry != null) {
+                            return true;
+                        }
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid tar
+                }
+            } else {
+                // Try TAR for unknown extensions
+                try {
+                    InputStream is = new FileInputStream(file);
+                    try (org.apache.commons.compress.archivers.tar.TarArchiveInputStream tais = new org.apache.commons.compress.archivers.tar.TarArchiveInputStream(is)) {
+                        org.apache.commons.compress.archivers.tar.TarArchiveEntry entry = tais.getNextTarEntry();
+                        if (entry != null) {
+                            return true;
+                        }
+                    }
+                } catch (Exception ignore) {
+                    // Not a valid tar
+                }
+            }
+
+            return false;
+        } catch (Exception e) {
+            return false;
+        }
     }
 
     private static void searchInArchiveCombined(File archive, String patternLower, Pattern filenameRegex, Pattern contentPattern, boolean caseSensitive, SearchCallback callback) {
         if (callback != null && callback.isCancelled()) return;
         String name = archive.getName().toLowerCase();
         try {
-            if (name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war")) {
+            if (name.endsWith(".car") || name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war")) {
                 try (ZipInputStream zis = new ZipInputStream(new FileInputStream(archive))) {
                     ZipEntry entry;
                     while ((entry = zis.getNextEntry()) != null) {
@@ -1037,7 +1161,7 @@ public class FileOperations {
 
         String name = archive.getName().toLowerCase();
         try {
-            if (name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war")) {
+            if (name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war") || name.endsWith(".car")) {
                 extractZip(archive, targetDir, callback);
             } else if (name.endsWith(".7z")) {
                 extract7z(archive, targetDir, callback);
@@ -1046,7 +1170,40 @@ public class FileOperations {
             } else if (name.endsWith(".tar") || name.endsWith(".tar.gz") || name.endsWith(".tgz")) {
                 extractTar(archive, targetDir, callback);
             } else {
-                throw new IOException("Unsupported archive format: " + name);
+                // For unknown extensions, try to detect format by attempting to read
+                // First try ZIP (most common)
+                try {
+                    extractZip(archive, targetDir, callback);
+                    return; // Success
+                } catch (IOException zipEx) {
+                    // Not a zip, try other formats
+                }
+
+                // Try 7z
+                try {
+                    extract7z(archive, targetDir, callback);
+                    return; // Success
+                } catch (IOException sevenZEx) {
+                    // Not a 7z
+                }
+
+                // Try RAR
+                try {
+                    extractRar(archive, targetDir, callback);
+                    return; // Success
+                } catch (IOException rarEx) {
+                    // Not a rar
+                }
+
+                // Try TAR/TAR.GZ
+                try {
+                    extractTar(archive, targetDir, callback);
+                    return; // Success
+                } catch (IOException tarEx) {
+                    // Not a tar
+                }
+
+                throw new IOException("Unsupported or invalid archive format: " + name);
             }
         } catch (Exception e) {
             if (callback != null) {
@@ -1066,7 +1223,7 @@ public class FileOperations {
         }
 
         String name = archive.getName().toLowerCase();
-        if (!(name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war"))) {
+        if (!(name.endsWith(".car") || name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war"))) {
             throw new IOException("Unsupported archive format for in-memory zip extraction: " + archive.getName());
         }
 
@@ -1282,7 +1439,7 @@ public class FileOperations {
     public static boolean supportsArchiveRewrite(File archive) {
         if (archive == null) return false;
         String name = archive.getName().toLowerCase();
-        return name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war");
+        return name.endsWith(".car") || name.endsWith(".zip") || name.endsWith(".jar") || name.endsWith(".war");
     }
 
     public static void rewriteArchiveFromDirectory(File sourceDir, File targetArchive, String password, ProgressCallback callback) throws IOException {

src/main/java/cz/kamma/kfmanager/ui/FilePanelTab.java

@@ -1162,10 +1162,12 @@ public class FilePanelTab extends JPanel {
                     int row = fileTable.getSelectedRow();
                     if (row >= 0) {
                         FileItem item = (viewMode == ViewMode.BRIEF) ? tableModel.getItemFromBriefLayout(row, briefCurrentColumn) : tableModel.getItem(row);
-                        if (item != null && (item.isDirectory() || FileOperations.isArchiveFile(item.getFile()))) {
+                        if (item != null && !item.isFtp()) {
+                            if (item.isDirectory() || (item.getFile() != null && FileOperations.canOpenAsArchive(item.getFile()))) {
                                 openSelectedItem();
                             }
                         }
+                    }
                     e.consume();
                 } else if (e.getKeyCode() == java.awt.event.KeyEvent.VK_PAGE_UP && e.isControlDown()) {
                     navigateUp();
@@ -2063,7 +2065,7 @@ public class FilePanelTab extends JPanel {
             
             if (item.getName().equals("..")) {
                 navigateUp();
-            } else if (FileOperations.isArchiveFile(item.getFile())) {
+            } else if (FileOperations.canOpenAsArchive(item.getFile())) {
                 rememberArchiveReturnState(item.getFile());
                 final File archiveFile = item.getFile();
                 
@@ -2097,7 +2099,7 @@ public class FilePanelTab extends JPanel {
                 );
             } else if (item.isDirectory()) {
                 loadDirectory(item.getFile());
-            } else if (item.getFile().isFile()) {
+            } else if (item.getFile() != null && item.getFile().isFile()) {
                 openFileNative(item.getFile());
             }
         }
@@ -2610,7 +2612,7 @@ public class FilePanelTab extends JPanel {
 
         if (item.getName().equals("..")) {
             navigateUp();
-        } else if (FileOperations.isArchiveFile(item.getFile())) {
+        } else if (FileOperations.canOpenAsArchive(item.getFile())) {
             rememberArchiveReturnState(item.getFile());
             final File archiveFile = item.getFile();
             
@@ -2634,7 +2636,7 @@ public class FilePanelTab extends JPanel {
             );
         } else if (item.isDirectory()) {
             loadDirectory(item.getFile());
-        } else if (item.getFile().isFile()) {
+        } else if (item.getFile() != null && item.getFile().isFile()) {
             openFileNative(item.getFile());
         }
     }
@@ -4882,7 +4884,7 @@ public class FilePanelTab extends JPanel {
                     }
                 };
 
-                if (archiveLower.endsWith(".zip") || archiveLower.endsWith(".jar") || archiveLower.endsWith(".war")) {
+                if (archiveLower.endsWith(".car") || archiveLower.endsWith(".zip") || archiveLower.endsWith(".jar") || archiveLower.endsWith(".war")) {
                     FileOperations.extractZipArchiveFromMemory(archive, tempDir.toFile(), callback);
                 } else {
                     FileOperations.extractArchive(archive, tempDir.toFile(), callback);