From 604417d8b2842e3683b69ee2635f7a366a96446b Mon Sep 17 00:00:00 2001
From: Matthias Jaros <jarlucmat@mailbox.org>
Date: Mon, 30 Mar 2026 12:20:33 +0200
Subject: Refactored cli option parsing and added -file option. Refactored
 reading of hosts to have less redundancy.

---
 .../java/com/it_jaros/network_scanner/Scanner.java | 35 ++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

(limited to 'src/main/java/com/it_jaros/network_scanner/Scanner.java')

diff --git a/src/main/java/com/it_jaros/network_scanner/Scanner.java b/src/main/java/com/it_jaros/network_scanner/Scanner.java
index d70a446..0969c5a 100644
--- a/src/main/java/com/it_jaros/network_scanner/Scanner.java
+++ b/src/main/java/com/it_jaros/network_scanner/Scanner.java
@@ -1,7 +1,12 @@
 package com.it_jaros.network_scanner;
 
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.net.*;
+import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.List;
@@ -9,6 +14,7 @@ import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.locks.LockSupport;
+import java.util.stream.Stream;
 
 public class Scanner {
 
@@ -31,16 +37,41 @@ public class Scanner {
     }
 
     public List<ScanResult> scan(ScanOptions options) {
+        if (options.file() != null) {
+            return scanHosts(options.file(), options.ports());
+        }
         return scanHosts(options.targetHosts(), options.ports());
     }
 
+    public List<ScanResult> scanHosts(String sourceFile, String ports) {
+        try (BufferedReader reader = Files.newBufferedReader(Path.of(sourceFile))) {
+            return scanHosts(reader.lines(), ports);
+        } catch (FileNotFoundException | NoSuchFileException e) {
+            System.out.printf("Could not open file %s%n", sourceFile);
+        } catch (IOException e) {
+            System.out.printf("Error while trying to read hosts: %s -> %s %n", e.getClass().getSimpleName(), e.getMessage());
+        }
+
+        return List.of();
+    }
+
     public List<ScanResult> scanHosts(List<String> targetHosts, String ports) {
+        try (Stream<String> stream = targetHosts.stream()){
+            return scanHosts(stream, ports);
+        } catch (IOException e) {
+            System.out.printf("Error while trying to read hosts: %s -> %s %n", e.getClass().getSimpleName(), e.getMessage());
+        }
+
+        return List.of();
+    }
+
+    public List<ScanResult> scanHosts(Stream<String> hosts, String ports) throws IOException {
         List<ScanResult> results = new ArrayList<>();
         progressBar.start();
         try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
             List<Future<ScanResult>> futures = new ArrayList<>();
             Semaphore maxHosts = new Semaphore(maxHostsLimit);
-            for (String host : targetHosts) {
+            hosts.forEach((final String host) -> {
                 maxHosts.acquireUninterruptibly();
                 futures.add(executor.submit(() -> {
                     try {
@@ -49,7 +80,7 @@ public class Scanner {
                         maxHosts.release();
                     }
                 }));
-            }
+            });
 
             futures.forEach((Future<ScanResult> f) -> {
                 try {
-- 
cgit v1.3.1