Added cancel to SubnetDevices and fixed blocking UI bug #PLAY_BETA

Author: stealthcopter

app/src/main/java/com/stealthcotper/networktools/MainActivity.java

@@ -206,7 +206,7 @@ private void doPortScan() throws Exception {
         final long startTimeMillis = System.currentTimeMillis();
 
         // Perform an asynchronous port scan
-        PortScan.onAddress(ipAddress).setPortsAll().setMethodTCP().doScan(new PortScan.PortListener() {
+        PortScan portScan = PortScan.onAddress(ipAddress).setPortsAll().setMethodTCP().doScan(new PortScan.PortListener() {
             @Override
             public void onResult(int portNo, boolean open) {
                 if (open) appendResultsText("Open: " + portNo);
@@ -219,14 +219,16 @@ public void onFinished(ArrayList<Integer> openPorts) {
             }
         });
 
+        // Below is example of how to cancel a running scan
+        // portScan.cancel();
     }
 
 
     private void findSubnetDevices() {
 
         final long startTimeMillis = System.currentTimeMillis();
 
-        SubnetDevices.fromLocalAddress().findDevices(new SubnetDevices.OnSubnetDeviceFound() {
+        SubnetDevices subnetDevices = SubnetDevices.fromLocalAddress().findDevices(new SubnetDevices.OnSubnetDeviceFound() {
             @Override
             public void onDeviceFound(Device device) {
                 appendResultsText("Device: " + device.ip+" "+ device.hostname);
@@ -239,6 +241,10 @@ public void onFinished(ArrayList<Device> devicesFound) {
                 appendResultsText("Finished "+timeTaken+" s");
             }
         });
+
+        // Below is example of how to cancel a running scan
+        // subnetDevices.cancel();
+
     }
 
     @Override

build.gradle

@@ -30,6 +30,6 @@ subprojects {
   ext.targetSdkVer = 27
   ext.supportLibVer = "27.1.1"
 
-  ext.appVersionName = "0.4.1"
-  ext.appVersionCode = 15
+  ext.appVersionName = "0.4.2"
+  ext.appVersionCode = 16
 }

library/src/main/java/com/stealthcopter/networktools/PortScan.java

@@ -288,7 +288,7 @@ public void cancel() {
     }
 
     /**
-     * Perform a synchronous port scan and return a list of open ports
+     * Perform a synchronous (blocking) port scan and return a list of open ports
      *
      * @return - ping result
      */
@@ -320,7 +320,7 @@ public ArrayList<Integer> doScan() {
     }
 
     /**
-     * Perform an asynchronous port scan
+     * Perform an asynchronous (non-blocking) port scan
      *
      * @param portListener - the listener to fire portscan results to.
      * @return - this object so we can cancel the scan if needed

library/src/main/java/com/stealthcopter/networktools/SubnetDevices.java

@@ -21,6 +21,7 @@ public class SubnetDevices {
     private ArrayList<Device> devicesFound;
     private OnSubnetDeviceFound listener;
     private int timeOutMillis = 2500;
+    private boolean cancelled = false;
 
     // This class is not to be instantiated
     private SubnetDevices() {
@@ -134,31 +135,53 @@ public SubnetDevices setTimeOutMillis(int timeOutMillis) throws IllegalArgumentE
         return this;
     }
 
+    /**
+     * Cancel a running scan
+     */
+    public void cancel() {
+        this.cancelled = true;
+    }
 
-    public void findDevices(final OnSubnetDeviceFound listener) {
+    /**
+     * Starts the scan to find other devices on the subnet
+     *
+     * @param listener - to pass on the results
+     * @return this object so we can call cancel on it if needed
+     */
+    public SubnetDevices findDevices(final OnSubnetDeviceFound listener) {
 
         this.listener = listener;
 
+        cancelled = false;
         devicesFound = new ArrayList<>();
 
-        ExecutorService executor = Executors.newFixedThreadPool(this.noThreads);
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
 
-        for (final String add : addresses) {
-            Runnable worker = new SubnetDeviceFinderRunnable(add);
-            executor.execute(worker);
-        }
+                ExecutorService executor = Executors.newFixedThreadPool(noThreads);
 
-        // This will make the executor accept no new threads
-        // and finish all existing threads in the queue
-        executor.shutdown();
-        // Wait until all threads are finish
-        try {
-            executor.awaitTermination(1, TimeUnit.HOURS);
-        } catch (InterruptedException e) {
-            e.printStackTrace();
-        }
+                for (final String add : addresses) {
+                    Runnable worker = new SubnetDeviceFinderRunnable(add);
+                    executor.execute(worker);
+                }
 
-        this.listener.onFinished(devicesFound);
+                // This will make the executor accept no new threads
+                // and finish all existing threads in the queue
+                executor.shutdown();
+                // Wait until all threads are finish
+                try {
+                    executor.awaitTermination(1, TimeUnit.HOURS);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+                listener.onFinished(devicesFound);
+
+            }
+        }).start();
+
+        return this;
     }
 
     private synchronized void subnetDeviceFound(Device device) {
@@ -175,6 +198,9 @@ public class SubnetDeviceFinderRunnable implements Runnable {
 
         @Override
         public void run() {
+
+            if (cancelled) return;
+
             try {
                 InetAddress ia = InetAddress.getByName(address);
                 PingResult pingResult = Ping.onAddress(ia).setTimeOutMillis(timeOutMillis).doPing();