pt 1 in reviving the android build (copied from pm 28a1, wish me luck)

mobile/android/thirdparty/com/keepsafe/switchboard/DeviceUuidFactory.java

@@ -0,0 +1,70 @@
+/*
+   Copyright 2012 KeepSafe Software Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+package com.keepsafe.switchboard;
+
+import java.util.UUID;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+/**
+ * Generates a UUID and stores is persistent as in the apps shared preferences.
+ * 
+ * @author Philipp Berner
+ */
+public class DeviceUuidFactory {
+    protected static final String PREFS_FILE = "com.keepsafe.switchboard.uuid";
+    protected static final String PREFS_DEVICE_ID = "device_id";
+
+    private static UUID uuid = null;
+
+    public DeviceUuidFactory(Context context) {
+        if (uuid == null) {
+            synchronized (DeviceUuidFactory.class) {
+                if (uuid == null) {
+                    final SharedPreferences prefs = context
+                            .getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
+                    final String id = prefs.getString(PREFS_DEVICE_ID, null);
+
+                    if (id != null) {
+                        // Use the ids previously computed and stored in the prefs file
+                        uuid = UUID.fromString(id);
+                    } else {
+                        uuid = UUID.randomUUID();
+
+                        // Write the value out to the prefs file
+                        prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString()).apply();
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns a unique UUID for the current android device. As with all UUIDs,
+     * this unique ID is "very highly likely" to be unique across all Android
+     * devices. Much more so than ANDROID_ID is.
+     *
+     * The UUID is generated with <code>UUID.randomUUID()</code>.
+     *
+     * @return a UUID that may be used to uniquely identify your device for most
+     *         purposes.
+     */
+    public UUID getDeviceUuid() {
+        return uuid;
+    }
+
+}