Difference between revisions of "OM2M/one/REST API"

Revision as of 10:05, 14 December 2015

Install a rest client

• For this section, you need a REST client to send HTTP request (GET, POST, UPDATE, DELETE) to the OM2M platform.
• You can use the "Client REST Simple" (https://chrome.google.com/webstore/detail/simple-rest-client/fhjcajmcbmldlhcimfajhfbgofnpcjmb), or Postman (http://www.getpostman.com) google chrome extension or any other rest client.

Simple REST client inteface

• The authentification is handle using a specific oneM2M header: X-M2M-Origin. This has to be specified in every request to identify the sender.

Retrieve a resource

• HTTP request:

• HTTP response:

<?xml version="1.0" encoding="UTF-8"?>
<m2m:cb xmlns:m2m="http://www.onem2m.org/xml/protocols" rn="in-cse">
    <ty>5</ty>
    <ri>/in-cse</ri>
    <ct>20151104T150228</ct>
    <lt>20151104T150228</lt>
    <acpi>/in-cse/acp-563660429</acpi>
    <cst>1</cst>
    <csi>in-cse</csi>
    <srt>1 2 3 4 5 9 14 15 16 17 23</srt>
    <poa>http://127.0.0.1:8080/</poa>
</m2m:cb>

Discover resources based on their search strings

• You can discover available resources based on their search strings using the discovery resource. The fu parameter (stands for "Filter Usage") indicate that it is a discovery request. The lbl ("Label") indicate the specific label you what to filter.
• HTTP request:

• HTTP response:

<?xml version="1.0" encoding="UTF-8"?>
<m2m:disres xmlns:m2m="http://www.onem2m.org/xml/protocols">
    <ref ty="2">/in-cse/ae_name1</ref>
</m2m:disres>

Create a "MY_SENSOR" application

• Send a HTTP request with the following parameters to create a MY_SENSOR application on the gateway.

• In the creation we have two important headers:
  • Content-Type: this header has 2 informations seperated by a semicolon
    • The format of the exchange, here "application/xml"
    • The resource type to be created, here "ty=2" (2 for AE, see oneM2M spec TS-0004, Table 6.3.3.2.11-1)
  • X-M2M-NM: the name of the resource to be created

<om2m:ae xmlns:om2m="http://www.onem2m.org/xml/protocols">
    <api>app-sensor</api>
    <lbl>Type/sensor Category/temperature Location/home</lbl>
    <rr>false</rr>
</om2m:ae>

• HTTP response:

<?xml version="1.0" encoding="UTF-8"?>
<m2m:ae xmlns:m2m="http://www.onem2m.org/xml/protocols" rn="MY_SENSOR">
    <ty>2</ty>
    <ri>ae-CAE449907766</ri>
    <pi>/in-cse</pi>
    <ct>20151104T151858</ct>
    <lt>20151104T151858</lt>
    <lbl>Type/sensor Category/temperature Location/home</lbl>
    <acpi>/in-cse/acp-89704715</acpi>
    <api>app-sensor</api>
    <aei>CAE449907766</aei>
    <rr>false</rr>
</m2m:ae>

• Here, the application has been created and can be accessed using 2 different URIs:
  • Unstructured URI: this URI is the ri node in the AE representation or present in the Content-Location header in the creation response. In our case we have "/in-cse/ae-CAE449907766"
  • Structured URI: this URI use the names of the resources hierarchically to get the resource. Here we will simple have "/in-cse/MY-SENSOR".
• You can check the created application on the web interface.

Create a DESCRIPTOR container

• Send a HTTP request with the following parameters to create a DESCRIPTOR container resource under the MY_SENSOR application.

<om2m:cnt xmlns:om2m="http://www.onem2m.org/xml/protocols">
</om2m:cnt>

• HTTP response

<?xml version="1.0" encoding="UTF-8"?>
<m2m:cnt xmlns:m2m="http://www.onem2m.org/xml/protocols" rn="DESCRIPTOR">
    <ty>3</ty>
    <ri>cnt-478855064</ri>
    <pi>/in-cse/ae-CAE449907766</pi>
    <ct>20151104T155844</ct>
    <lt>20151104T155844</lt>
    <acpi>/in-cse/acp-89704715</acpi>
    <cni>0</cni>
    <cbs>0</cbs>
</m2m:cnt>

• As the AE, there is two ways to access the resource:
  • Unstructured URI: which is '/in-cse/cnt-478855064'
  • Structure URI: which is the Structured URI of the AE plus the name of the container, in our case "/in-cse/MY_SENSOR/DESCRIPTOR"
• Check the created container on the web interface.

Create a description contentInstance

• Send a HTTP request with the following parameters to create a description content instance resource under the "DESCRIPTOR" container.

	
<om2m:cin xmlns:om2m="http://www.onem2m.org/xml/protocols">
    <cnf>message</cnf>
    <con>
        <obj>
            <str name="type" val="Temperature_Sensor"/>
            <str name="location" val="Home"/>
            <str name="appId" val="MY_SENSOR"/>
            <op name="getValue" href="/in-cse/MY_SENSOR/DATA/la" 
         in="obix:Nil" out="obix:Nil" is="retrieve"/>
        </obj>
    </con>
</om2m:cin>

• Check the created content instance on the web interface.

Create a DATA container

• Send a HTTP request with the following parameters to create a "DATA" container resource under the "MY_SENSOR" application.

<om2m:cnt xmlns:om2m="http://www.onem2m.org/xml/protocols">
</om2m:cnt>

• Check the created container on the web interface.

Create a data contentInstance

• Send a HTTP request with the following parameters to create a data content instance resource under the "DATA" container.

	
<obj>
     <str name="appId" val="MY_SENSOR"/>
     <str name="category" val="temperature "/>
     <int name="data" val="27"/>
     <int name="unit" val="celsius"/>
</obj>

• Check the created content instance on the web interface.

Subscribe to MY_SENSOR data

• Download the monitor server sample from this link: Monitor-bin. (The monitor source code is available here: Monitor.java ).
• Extract the rar file.
• You can configure the Monitor listening port and context using the "config.properties"
• Start the Monitor server using the following command:

> java -jar monitor.jar

• By default the monitor starts listening on port=1400 and context=/monitor.

Monitor console: the server is started

• Send a HTTP request with the following parameters to create a "Subscription" resource for receive asynchronously events from "MY_SENSOR" application.
• The monitor listening URL (http://127.0.0.1:1400/monitor) should be added on the "nu" tag of the subscription representation.

<m2m:sub xmlns:m2m="http://www.onem2m.org/xml/protocols">
    <nu>http://localhost:1400/monitor</nu>
    <nct>2</nct>
</m2m:sub>

• Check the created subscription on the web interface.

• Create a new event content instance resource under the "DATA" container.
• The new event is published to interested subscribers by the gateway.
• Here is an example of the "Notify" XML representation:

<?xml version="1.0" encoding="UTF-8"?>
<m2m:sgn xmlns:m2m="http://www.onem2m.org/xml/protocols">
   <nev>
      <rep rn="cin_name1">
         <ty>4</ty>
         <ri>cin-46677406</ri>
         <pi>/in-cse/cnt-397256037</pi>
         <ct>20151104T162611</ct>
         <lt>20151104T162611</lt>
         <st>0</st>
         <cnf>message</cnf>
         <cs>11</cs>
         <con>hello world</con>
      </rep>
      <rss>1</rss>
   </nev>
   <sud>false</sud>
   <sur>/in-cse/MY_SENSOR/DATA/SUB_MY_SENSOR</sur>
</m2m:sgn>

• The Monitor receives a "Notify" resource including the new "ContentInstance" encoded in Base64.
• Remember that the "Notify" resource has a generic structure to support notifications for other type of resources such as "AE", "Container", "Group", AccessRight, etc.