The Ubidots Java API Client makes calls to the Ubidots API. You can get the library from our Github account.

Add this dependency to your project's POM:

<dependency>
  <groupId>com.ubidots</groupId>
  <artifactId>ubidots-java</artifactId>
  <version>1.6.5</version>
</dependency>

Ubidots for Java is available as an unbundled jar, with the following dependencies:

• Gson, the open-source Google JSON library
• Apache HttpCore, Apache's open-source implementation of HTTP
• Apache HttpClient, Apache's open-source implementation of an HTTP agent
• Apache Commons - Logging, a dependency of Apache HttpClient (no logging is actually used)

For the latest version of the dependencies, follow the above links. To download the latest versions at the time of writing, use the commands below:

$ wget http://google-gson.googlecode.com/files/google-gson-2.2.4-release.zip
$ wget http://apache.claz.org//httpcomponents/httpcore/binary/httpcomponents-core-4.3.1-bin.tar.gz
$ wget http://apache.claz.org//httpcomponents/httpclient/binary/httpcomponents-client-4.3.3-bin.tar.gz
$ wget http://mirror.sdunix.com/apache//commons/logging/binaries/commons-logging-1.1.3-bin.tar.gz

Before playing with the API you must be able to connect to it using your private API key, which can be found in your profile.

If you don't have an account yet, you can create one here.

Once you have your API key, you can connect to the API by creating an ApiClient instance. First, import all classes from the com.ubidots package:

import com.ubidots.*;

Let's assume your API key is: "7fj39fk3044045k89fbh34rsd9823jkfs8323" then your code would look like this:

ApiClient api = new ApiClient("7fj39fk3044045k89fbh34rsd9823jkfs8323");

Now you have an instance of the ApiClient class ("api") which can be used to connect to the API service.

As you might know by now, a data source represents a device or a virtual source.

This line creates a new data source:

DataSource dataSource = api.createDatasource("myNewDs");

This new data source can be used to track different variables, so let's create one.

A variable is a time-series containing different values over time. Let's create one:

Variable variable = dataSource.createVariable("myNewVar");

Now you have a new variable, so let's create a new value for this variable.

Given the instantiated variable, you can save a new value with the following line:

variable.saveValue(10);

Unlike the Python library, the timestamp for the value is automatically created for the value on the client-side.

Values may also be added in bulk. This is especially useful when data is gathered offline and connection to the internet is limited.

int[] values = new int[5];        // double[] values also accepted
values[0] = 10;
values[1] = 1;
values[2] = 8;
values[3] = 3;
values[4] = 5;

long[] timestamps = new long[5];
timestamps[0] = 1380558972614l;
timestamps[1] = 1380558972915l;
timestamps[2] = 1380558973516l;
timestamps[3] = 1380558973617l;
timestamps[4] = 1380561122434l;

var.saveValues(values, timestamps);

To get the values for a variable, use the method getValues() in an instance of the class Variable.

Value[] values = variable.getValues();

If you want to get all your data sources you can use the instance of the API directly:

DataSource[] dataSources = api.getDataSources();

Each data source has a unique id that tells the server which one to retrieve.

For example, if a data source has the id 51c99cfdf91b28459f976414, it can be retrieved using the method getDatasource(String) of the ApiClient instance:

DataSource mySpecificDataSource = api.getDataSource("51c99cfdf91b28459f976414");

You can also retrieve all the variables of a data source:

Variable[] allDataSourceVariables = dataSource.getVariables();

As with data sources, use your variable's id to retrieve the details about a variable:

Variable mySpecificVariable = api.getVariable("56799cf1231b28459f976417");

You can use the Ubidots statistics endpoint by calling the specific method:

• getMean()
• getVariance()
• getMin()
• getMax()
• getCount()
• getSum()

This methods are present in your variable instance.

Usage example

Variable mySpecificVariable = api.getVariable("56799cf1231b28459f976417");
double mean = mySpecificVariable.getMean();