create a simple energy meter "backend" and "frontend"'-

Job Description:

Java Application with SpringBoot, JPA, Hibernate, Postges, Rest-Service

You write an application based on a given sourcecode (reimplementation with changes).

The given sourcecode of a plain java application collects data from a serial interface (/tty/USB0), interpret these data and save them to the filesystem. [watch: [login to view URL]]

After you have created the database tables. Your task is to collect and interpret data as mentioned above and save them to the database. You will write a REST-Service to provide the collected data and write some web-pages (responsive design). [watch: [login to view URL]]

The data are metering data and contains the consumption and the power of three phases. [watch: [login to view URL] & [login to view URL]]

Please, watch the process as specified. [watch: [login to view URL]]

The data that has to be processed, comes from an energy meter over the IR-diod to the serial interface /tty/USB0. Because the application runs on a linux device, this interface is a “normal” file to read. [watch: [login to view URL]]

First, the application stores the values plane into a table (may be called ‘raw-data’) [watch: [login to view URL]]

Than there must be a ‘statistic-data’ table where the application stores one dataset for a minute, an hour, a day, a week, a month and a year by a type (resolution), implemented as an enumeration. This dataset contains the consumption of this period, a minimum-, a maximum- and an average value of the three phases and the timestamp.

Every minute, hour, day, week, month and year we get another dataset (INSERT). Within the period, the dataset will be updated for all fields [minute, hour, day, week, month, year]:

[logic:] set [login to view URL] = [login to view URL]

set table.dataset.count++

set [login to view URL] = [login to view URL]

set [login to view URL] = [login to view URL]

set [login to view URL] = [login to view URL] - [login to view URL] of this [login to view URL]

set ([login to view URL] + [login to view URL])/2

if [login to view URL]>[login to view URL] -> set maxValue

if [login to view URL]<[login to view URL] -> set minValue

...same for phase2 and phase3

[/logic]

Every two seconds, the meter will provide a new realtime dataset as an input.

For the client-side we need some REST endpoints providing the data with json.

An endpoint to provide long term polling to give all realtime data every two seconds

An endpoint to provide the statistic values for a timeframe and the resolution (type of the dataset)

To visualize the result, there is a responsive web page in multilanguage to show the realtime data like the follwing:

actual consumption

actual power P1

actual power P2

actual power P3

There is the possibility to switch the language, if there are more then one language configured (configured by different files for each language).

There is the possibility to show details by hitting a chart button -> switch to a new site with a bar chart showing the consumption of each days of the current week.

You don’t have to implement the shown “refresh-button” from the mockup.

There must also be a settings-page to type a key, validated by a RSA-key or something similar. If the validation was successful once, there will be shown an other page to view statistics for a given time frame and different granularities (minute - for an hour; hour - for a day; day - for a week; day - for a month; month - for a year).

To create a valid key 6-12 characters, you need to implement a code generator with the key mentioned above.

The application must have a test covering for all logics.

The IDE must be Eclipse (or STS) or intelliJ. The build system is gradle.

You deliver the sourcecode, an executable jar (SpringBoot) containing the Webservice and the html pages.

Because you are a professional developer, it might be very easy for you to implement this small tool. If you aren’t a full stack developer, you can send an offer for the backend or the frontend part.

Навыки: Java, Java Spring, JavaScript, PostgreSQL, Архитектура ПО

ID проекта: #19217448