jscanner

commit dc2e873b73de4fce58cd120ac7479ea340940b54
parent 8a42dfd1c69895cdd9946e71079218b307577ca3
Author: Matthias Jaros <jaros@mailbox.org>
Date:   Sun, 22 Feb 2026 20:30:46 +0100

Refactored port scan method and fixed open ports indicator

Diffstat:
M
src/main/java/com/it_jaros/networkScanner/ProgressBar.java
 | 
17
+++++++++++------
M
src/main/java/com/it_jaros/networkScanner/Scanner.java
 | 
33
+++++++++++++++++++--------------

2 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/src/main/java/com/it_jaros/networkScanner/ProgressBar.java b/src/main/java/com/it_jaros/networkScanner/ProgressBar.java
@@ -32,20 +32,21 @@ public class ProgressBar {
     private void drawBar(Progress progress) {
         System.out.print("\u001b[2K\r");
         System.out.println(createBar(
-                progress.host() + " open=" + progress.open().get(),
+                progress.host(),
+                progress.open().get(),
                 progress.done().get(),
                 progress.total()));
     }
 
-    public String createBar(String label, int done, int total) {
+    public String createBar(String label, int open, int done, int total) {
         int width = 30;
         double pct = total == 0 ? 1.0 : (done / (double) total);
         int filled = (int) (pct * width);
 
-        String b = "[" + "#".repeat(filled) + "-".repeat(width - filled) + "]";
+        String brackets = "[" + "#".repeat(filled) + "-".repeat(width - filled) + "]";
         int percent = (int) (pct * 100);
 
-        return String.format("%-25s %s %3d%% (%d/%d)", label, b, percent, done, total);
+        return String.format("%-40s open=%s %s %3d%% (%d/%d)", label, open, brackets, percent, done, total);
     }
 
     public void stop() {
@@ -58,7 +59,11 @@ public class ProgressBar {
         }
     }
 
-    void onPortFinished(Progress p) {
-        p.done().incrementAndGet();
+    void onPortFinished(Progress progress) {
+        progress.done().incrementAndGet();
+    }
+
+    public void onPortOpen(Progress progress) {
+        progress.open().incrementAndGet();
     }
 }
diff --git a/src/main/java/com/it_jaros/networkScanner/Scanner.java b/src/main/java/com/it_jaros/networkScanner/Scanner.java
@@ -46,7 +46,7 @@ public class Scanner {
                 PortRange portsRange = new PortRange(ports);
                 Progress progress = new Progress(target, portsRange.getTotal(), new AtomicInteger(), new AtomicInteger());
                 hosts.add(progress);
-                results.add(scanTargetAsync(target, portsRange, delayInNanos, executor, progress));
+                results.add(scanTarget(target, portsRange, delayInNanos, executor, progress));
             }
             progressBar.start(hosts);
         }
@@ -56,14 +56,24 @@ public class Scanner {
         return results;
     }
 
-    private ScanResult scanTargetAsync(String target, PortRange portRange, long delayInNanos, ExecutorService executor, Progress p) {
-        AtomicLong nextStartNanos = new AtomicLong(System.nanoTime());
+    private ScanResult scanTarget(String target, PortRange portRange, long delayInNanos, ExecutorService executor,
+            Progress p) {
+        AtomicLong scanSlotFactory = new AtomicLong(System.nanoTime());
         Queue<Integer> openPorts = new ConcurrentLinkedQueue<>();
         while (portRange.hasNext()) {
             final int currentPort = portRange.next();
             executor.submit(() -> {
                 try {
-                    scanPortsAsync(target, delayInNanos, nextStartNanos, openPorts, currentPort);
+                    if (delayInNanos > 0) {
+                        long mySlot = scanSlotFactory.getAndAdd(delayInNanos);
+                        long wait = mySlot - System.nanoTime();
+                        if (wait > 0)
+                            LockSupport.parkNanos(wait);
+                    }
+                    if (isTargetPortOpen(target, currentPort)) {
+                        openPorts.add(currentPort);
+                        progressBar.onPortOpen(p);
+                    }
                 } finally {
                     progressBar.onPortFinished(p);
                 }
@@ -72,19 +82,12 @@ public class Scanner {
         return new ScanResult(target, openPorts);
     }
 
-    private void scanPortsAsync(String target, long delayInNanos, AtomicLong nextStartNanos, Queue<Integer> openPorts,
-            int currentPort) {
-        if (delayInNanos > 0) {
-            long mySlot = nextStartNanos.getAndAdd(delayInNanos);
-            long wait = mySlot - System.nanoTime();
-            if (wait > 0)
-                LockSupport.parkNanos(wait);
-        }
+    private boolean isTargetPortOpen(String target, int port) {
         socketCap.acquireUninterruptibly();
         counter.inc();
         try (Socket socket = new Socket()) {
-            socket.connect(new InetSocketAddress(target, currentPort), timeoutInMillis);
-            openPorts.add(currentPort);
+            socket.connect(new InetSocketAddress(target, port), timeoutInMillis);
+            return true;
         } catch (ConnectException | SocketTimeoutException ignored) {
         } catch (IOException e) {
             System.out.println(e.getClass().getSimpleName() + ": " + e.getMessage());
@@ -92,5 +95,7 @@ public class Scanner {
             counter.dec();
             socketCap.release();
         }
+
+        return false;
     }
 }