RADAR-base/radar-commons-android

Name: radar-commons-android

Owner: RADAR-CNS

Owner: RADAR-CNS

Description: Base android functionality for the RADAR passive application plugins

Created: 2017-03-20 15:09:34.0

Updated: 2017-10-09 14:26:05.0

Pushed: 2018-01-31 13:03:27.0

Homepage: null

Size: 2767

Language: Java

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README

RADAR-Commons-Android

Base module for the RADAR passive remote monitoring app. Plugins for that app should implement the API from this base library. Also user interfaces should use this as a base. Currently, the main user interface is RADAR-AndroidApplication.

Configuration

This library takes the following firebase parameters:

| Parameter | Type | Default | Description | | ——— | —- | ——- | ———– | | kafka_rest_proxy_url | URL | <empty> | URL of a Kafka REST Proxy or RADAR-Gateway to send data to. | | schema_registry_url | URL | <empty> | URL of a Kafka Schema Registry to sync schemas with. | | management_portal_url | URL | <empty> | URL of the RADAR Management Portal. If empty, the Management Portal will not be used. | | unsafe_kafka_connection | boolean | false | Whether to accept unsafe HTTPS certificates. Only meant to be set to true in development environments. | | device_services_to_connect | string | <empty> | A space-separated list of device service providers to connect. The org.radarcns prefix may be excluded. | | kafka_records_send_limit | int | 1000 | Number of records to send in a single request. | | kafka_upload_rate | int (s) | 50 | Rate after which to send data. In addition, after every kafka_upload_rate divided by 5 seconds, if more than kafka_records_send_limit are in the buffer, these are sent immediately. | | database_commit_rate | int (ms) | 10000 (= 10 seconds) | Rate of committing new data to disk. If the application crashes, at most this interval of data will be lost. | | sender_connection_timeout | int (s) | 120 | HTTP timeout setting for data uploading. | | kafka_upload_minimum_battery_level | int (s) | 0.1 (= 10%) | Battery level percentage below which to stop sending data. Data will still be collected. | | max_cache_size_bytes | long (byte) | 450000000 | Maximum number of bytes per topic to store. | | send_only_with_wifi | boolean | true | Whether to send only when WiFi is connected. If false, for example LTE would also be used. | | send_with_compression | boolean | true | Send data with GZIP compression. This requires RADAR-Gateway to be installed in front of the Kafka REST Proxy. | | firebase_fetch_timeout_ms | long (ms) | 43200000 (= 12 hours) | Interval for fetching new Firebase configuration if the app is not active. |

Usage

Creating a plugin

To add device types to the passive remote monitoring Android app, create a plugin using the following steps (see the RADAR-Android-Pebble repository as an example):

1. Add the schemas of the data you intend to send to the RADAR-CNS Schemas repository. Your record keys should be org.radarcns.kafka.ObservationKey. Be sure to set the namespace property to org.radarcns.mydevicetype so that generated classes will be put in the right package. All values should have time and timeReceived fields, with type double. These represent the time in seconds since the Unix Epoch (1 January 1970, 00:00:00 UTC). Subsecond precision is possible by using floating point decimals. Until those schemas are published, generate them using Avro tools. Find avro-tools-1.8.1.jar by going to http://www.apache.org/dyn/closer.cgi/avro/, choosing a mirror, and then downloading avro-1.8.1/java/avro-tools-1.8.1.jar. You can now generate source code for a schema myschema.avsc with the following command:

    -jar avro-tools-1.8.2.jar compile -string schema path/to/myschema.avsc path/to/plugin/src/main/java
   

   Once the schemas are published as part of the central schemas repository, you can remove the generated files again. Do not publish a non-alpha version of your plugin without the central schemas being published, otherwise there may be class conflicts later on.
2. Create a new package org.radarcns.mydevicetype. In that package, create classes that:
   • implement org.radarcns.android.device.DeviceManager to connect to a device and collect its data, register all Kafka topics in its constructor.
   • implement org.radarcns.android.DeviceState to keep the current state of the device or simply use org.radarcns.android.BaseDeviceState.
   • subclass org.radarcns.android.device.DeviceService to run the device manager in.
   • subclass a org.radarcns.android.device.DeviceServiceProvider that exposes the new service.
3. Add a new service element to AndroidManifest.xml, referencing the newly created device service. Also add all the required permissions there.
4. Add the DeviceServiceProvider you just created to the device_services_to_connect property in app/src/main/res/xml/remote_config_defaults.xml.

Make a pull request once the code is working.

Creating an application

To create an Android App, follow the following steps:

1. Include this module in the Gradle dependencies, and also all plugins that you would like to use
2. Update your code with
   • A main activity that extends org.radarcns.android.MainActivity.
   • A main activity view that extends org.radarcns.android.MainActivityView. This should reference a layout and update its values based on the services that are connected to the main activity.
   • An application class that extends org.radarcns.android.RadarApplication.
   • If wanted, create a BroadcastListener that listens to the ACTION_BOOT_COMPLETED event and starts your MainActivity subclass. Configure it with the MainActivity.configureRunAtBoot(Class) method.
3. In AndroidManifest.xml, add your application and service. If wanted add your boot-listener to listen to ACTION_BOOT_COMPLETED events and set enabled to false.
4. Copy src/main/res/xml/remote_config_defaults_template.xml to app/src/main/res/xml/remote_config_defaults.xml and insert all needed values there.

Contributing

For latest code use dev branch. Code should be formatted using the Google Java Code Style Guide, except using 4 spaces as indentation.

If you want to contribute a feature or fix browse our issues, and please make a pull request.