added the ability to specify a path

src/main/java/com/pusher/client/PusherOptions.java

@@ -34,6 +34,7 @@ public class PusherOptions {
     private String host = "ws.pusherapp.com";
     private int wsPort = WS_PORT;
     private int wssPort = WSS_PORT;
+    private String path = "";
     private boolean useTLS = true;
     private long activityTimeout = DEFAULT_ACTIVITY_TIMEOUT;
     private long pongTimeout = DEFAULT_PONG_TIMEOUT;
@@ -183,10 +184,26 @@ public PusherOptions setWssPort(final int wssPort) {
         return this;
     }
 
+    /**
+     * The path to which connections will be made.
+     * <p>
+     * Note that if you wish to connect to a standard Pusher cluster, the
+     * convenience method setCluster will set the host and ports correctly from
+     * a single argument.
+     *
+     * @param path The path
+     * @return this, for chaining
+     */
+    public PusherOptions setPath(final String path) {
+        this.path = path;
+        return this;
+    }
+
     public PusherOptions setCluster(final String cluster) {
         host = "ws-" + cluster + "." + PUSHER_DOMAIN;
         wsPort = WS_PORT;
         wssPort = WSS_PORT;
+        path = "";
         return this;
     }
 
@@ -272,10 +289,11 @@ public long getPongTimeout() {
      */
     public String buildUrl(final String apiKey) {
         return String.format(
-                "%s://%s:%s/app/%s%s",
+                "%s://%s:%s%s/app/%s%s",
                 useTLS ? WSS_SCHEME : WS_SCHEME,
                 host,
                 useTLS ? wssPort : wsPort,
+                path,
                 apiKey,
                 URI_SUFFIX
         );

src/test/java/com/pusher/client/PusherOptionsTest.java

@@ -186,4 +186,17 @@ public void testSetProxy() {
     public void testGetProxyReturnDefaultProxy() {
         assertEquals(pusherOptions.getProxy(), Proxy.NO_PROXY);
     }
+
+    @Test
+    public void testCustomHostPortAnPathURLIsCorrect() {
+        pusherOptions.setHost("subdomain.example.com").setWsPort(8080).setWssPort(8181).setPath("/custom/path");
+        assertEquals(
+                pusherOptions.buildUrl(API_KEY),
+                "wss://subdomain.example.com:8181/custom/path/app/" +
+                        API_KEY +
+                        "?client=java-client&protocol=5&version=" +
+                        PusherOptions.LIB_VERSION
+        );
+    }
+
 }