Table of Contents

Registry Service

Mobile nodes Registry service, offering a RegistryCoreServer to talk with mobile clients, a Web Console interface to manage nodes with a web browser, and a REST API to exchange JSON data with other servers or clients.

The main objective of this service is to provide UUID to label mapping and vice-versa. This way you can map long and near-to-impossible to remember UUID strings to friendly names like an e-mail, a car plate, a proper noun, nickname, username or any other label you need.

Architecture

Screenshots

Web Console Interface screenshots for basic Admin operations. This is a CRUD interface.

CRUD stands for Create, Retrieve, Update, Delete (as in managing objects/entries in a database with a simple user interface, usually web based).

REST API

REST API services HTTP clients and helps them to manage nodes in the database from outside the Java server or client code, by making HTTP calls to predefined service routes.

api-client.sh
#!/bin/bash
 
export registry_host="registry.vm"
 
# Create node
# POST /api/nodes
 
curl \
  --header 'Content-type: application/json' \
  --request POST \
  --data '{"uuid":"1234","name":"mynode","info":"some_data"}' \
  http://$registry_host/api/nodes
 
# Retrieve node
# GET /api/nodes/:uuid_name
 
curl \
  --request GET \
  http://$registry_host/api/nodes/mynode
 
# Nodes list
# GET /api/nodes
 
curl \
  --request GET \
  http://$registry_host/api/nodes
 
# Search nodes
# GET /api/nodes/search/:uuid_name
 
curl \
  --request GET \
  http://$registry_host/api/nodes/search/myn
 
# Update node
# PUT /api/nodes/:uuid_name
 
curl \
  --header 'Content-type: application/json' \
  --request PUT \
  --data '{"uuid":"1234","name":"mynode","info":"some_other_data"}' \
  http://$registry_host/api/nodes/mynode
 
# Delete node
# DELETE /api/nodes/:uuid_name
 
curl \
  --request DELETE \
  http://$registry_host/api/nodes/mynode

More REST API usage samples can be found in the Registry/README file.

CrudLib API

CrudLib helps you to manage nodes in the database from inside the core server.

SnippetServer.java
// This sample is only a snippet, the complete code for a server can be found in the Registry service repository.
 
import crublib.CrudLib;
 
CrudLib.addNode(Json.parse(requestMessage.getPayload()));
 
CrudLib.getNode(requestMessage.getPayload());
 
CrudLib.lstNodes();
 
CrudLib.srchNodes(requestMessage.getPayload());
 
CrudLib.updNode(requestMessage.getPayload(), Json.parse(requestMessage.getPayload()));
 
CrudLib.delNode(requestMessage.getPayload());

Complete CrudLib usage can be found in the RegistryCoreServer.java file.

RequestInfo and ResponseInfo API

Handling RequestInfo and ResponseInfo objects any mobile client can interact with the Registry service and call all the methods available in the core server, just like we can do in the REST API or CrudLib.

RequestInfo and ResponseInfo basically have two attributes: type and payload, both set in the constructor.

RequestInfo and ResponseInfo types.

SnippetClient.java
// This sample is only a snippet, the complete code for a client can be found in the Registry service repository.
 
import modellibrary.RequestInfo;
import modellibrary.ResponseInfo;
 
public class RegistryCoreClient implements NodeConnectionListener {
    @Override
    public void connected(NodeConnection remoteCon) {
        // REQUEST send
        JSONObject xresult = new JSONObject();
        JSONObject xinfo = new JSONObject();
 
        try {
            xresult.put("uuid", "987654321");
            xresult.put("name", "mynode");
            xinfo.put("email", "mynode@example.com");
            xinfo.put("city", "Rio de Janeiro");
            xinfo.put("phone", "555-555-555");
            xinfo.put("birthday", "01/01/1970");
            xinfo.put("pass", "password");
            xresult.put("info", xinfo.toString());
        } catch (JSONException e1) {
            e1.printStackTrace();
        }
 
        ApplicationMessage appMessage4 = new ApplicationMessage();
        RequestInfo requestMessage4 = new RequestInfo(
                appMessage4.getSenderID(), "addNode", xresult.toString());
        appMessage4.setContentObject(requestMessage4);
        try {
            remoteCon.sendMessage(appMessage4);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        ApplicationMessage appMessage1 = new ApplicationMessage();
        RequestInfo requestMessage1 = new RequestInfo(
                appMessage1.getSenderID(), "lstNodes", "");
        appMessage1.setContentObject(requestMessage1);
        try {
            remoteCon.sendMessage(appMessage1);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        ApplicationMessage appMessage2 = new ApplicationMessage();
        RequestInfo requestMessage2 = new RequestInfo(
                appMessage2.getSenderID(), "srchNodes", "myn");
        appMessage2.setContentObject(requestMessage2);
        try {
            remoteCon.sendMessage(appMessage2);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        ApplicationMessage appMessage3 = new ApplicationMessage();
        RequestInfo requestMessage3 = new RequestInfo(
                appMessage3.getSenderID(), "getNode", "mynode");
        appMessage3.setContentObject(requestMessage3);
        try {
            remoteCon.sendMessage(appMessage3);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        ApplicationMessage appMessage5 = new ApplicationMessage();
        RequestInfo requestMessage5 = new RequestInfo(
                appMessage5.getSenderID(), "delNode", "mynode");
        appMessage5.setContentObject(requestMessage5);
        try {
            remoteCon.sendMessage(appMessage5);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    @Override
    public void newMessageReceived(NodeConnection remoteCon, Message message) {
        String className = message.getContentObject().getClass()
                .getCanonicalName();
 
        if (className != null) {
            // RESPONSE recv
            if (className.equals(ResponseInfo.class.getCanonicalName())) {
                ResponseInfo responseMessage = (ResponseInfo) Serialization
                        .fromJavaByteStream(message.getContent());
                System.out.println("[RegistryCoreClient] Response type: "
                        + responseMessage.getType() + " | payload: "
                        + responseMessage.getPayload());
            } else {
                System.out
                        .println("[RegistryCoreClient] Objeto desconhecido recebido do servidor: "
                                + className);
            }
        }
    }
}

Complete RequestInfo and ResponseInfo usage sample can be found in the RegistryCoreClient.java file.

Trying it out

We have made available a VM that is prepared to run Registry services (Core, Web and REST). With just a few commands you will be ready to test the service. You will need:

With the automated Vagrant setup all the process of setting up the project, installing the server OS (Linux Ubuntu), installing and configuring dependencies like Java, Play Framework, MySQL, DB migrations/evolutions and CoreDX DDS, as well as ContextNet's libraries and Gateway, all of this is taken care for you and can be repeated as many times as you need to rebuild the entire system to test new versions from scratch.

In the README file you can find more detailed information on how to run the VM. Just keep in mind that this VM was meant to test and run the code (it is a headless server), not to edit or develop. For developing you should visit the Download page to grab a copy of the LAC's ContextNet VM with Eclipse and samples already set for you.

Repository

Source code and VM setup are available at Github

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