1 files changed, 50 insertions, 0 deletions
diff --git a/src/main/java/com/it_jaros/networkScanner/Scanner.java b/src/main/java/com/it_jaros/networkScanner/Scanner.java
new file mode 100644
index 0000000..1f71f56
--- /dev/null
+++ b/src/main/java/com/it_jaros/networkScanner/Scanner.java
@@ -0,0 +1,50 @@
+package com.it_jaros.networkScanner;
+
+import java.io.IOException;
+import java.net.ConnectException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.util.List;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Semaphore;
+
+public class Scanner {
+                
+    private Counter counter = new Counter();
+    private final int socketLimitDefault = 1024;
+    
+    public Scanner() {}
+    
+    public List<Integer> scanPorts(String address) {
+        return scanPorts(address, socketLimitDefault);
+    }
+
+    public List<Integer> scanPorts(String address, int socketLimit) {
+        Queue<Integer> openPorts = new ConcurrentLinkedQueue<>();
+        Semaphore socketCap = new Semaphore(socketLimit);
+        try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
+            for (int port = 1; port < 65536; port++) {
+                final int currentPort = port;
+                executor.submit(() -> {
+                    socketCap.acquireUninterruptibly();
+                    counter.inc();
+                    try (Socket socket = new Socket()) {
+                        socket.connect(new InetSocketAddress(address, currentPort));
+                        openPorts.add(currentPort);
+                    } catch (ConnectException ignored) {
+                    } catch (IOException e) {
+                        System.out.println(e.getClass().getSimpleName() + ": " + e.getMessage());
+                    } finally {
+                        counter.dec();
+                        socketCap.release();
+                    }
+                });
+            }
+        }
+        System.out.println("Peak concurrent connects: " + counter.max());
+        return openPorts.stream().toList();
+    }
+}