Add validations to setSSLSocketFactory

Author: gusavila92

src/main/java/dev/gustavoavila/websocketclient/WebSocketClient.java

@@ -132,8 +132,10 @@ public abstract class WebSocketClient {
      */
     private volatile Thread reconnectionThread;
 
-
-    private SSLSocketFactory socketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
+    /**
+     * Allows to customize the SSL Socket factory instance
+     */
+    private SSLSocketFactory sslSocketFactory;
 
     /**
      * Initialize all the variables
@@ -153,11 +155,6 @@ public WebSocketClient(URI uri) {
         webSocketConnection = new WebSocketConnection();
     }
 
-
-    public void setSSLSocketFactory(SSLSocketFactory sslSocketFactory) {
-        socketFactory = sslSocketFactory;
-    }
-
     /**
      * Called when the WebSocket handshake has been accepted and the WebSocket
      * is ready to send and receive data
@@ -311,6 +308,21 @@ public void connect() {
         }
     }
 
+    /**
+     * Sets the SSL Socket factory used to create secure TCP connections
+     * @param sslSocketFactory SSLSocketFactory
+     */
+    public void setSSLSocketFactory(SSLSocketFactory sslSocketFactory) {
+        synchronized (globalLock) {
+            if (isRunning) {
+                throw new IllegalStateException("Cannot set SSLSocketFactory while WebSocketClient is running");
+            } else if (sslSocketFactory == null) {
+                throw new IllegalStateException("SSLSocketFactory cannot be null");
+            }
+            this.sslSocketFactory = sslSocketFactory;
+        }
+    }
+
     /**
      * Creates and starts the thread that will handle the WebSocket connection
      */
@@ -654,7 +666,10 @@ private boolean createAndConnectTCPSocket() throws IOException {
                                 socket.connect(new InetSocketAddress(uri.getHost(), 80), connectTimeout);
                             }
                         } else if (scheme.equals("wss")) {
-                            socket = socketFactory.createSocket();
+                            if (sslSocketFactory == null) {
+                                sslSocketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
+                            }
+                            socket = sslSocketFactory.createSocket();
                             socket.setSoTimeout(readTimeout);
 
                             if (port != -1) {