AVIS (means notify in French) is a simple multi purpose messaging framework based on Spring and RabbitMQ. Current implementations include notifications via Simple Email and Google Cloud Messaging (GCM). Any new implementations to different notification frameworks/technologies can be added into AVIS.
Avis project is a client-server project, where the client can be used by 3rd party application who wish to send notifications. It has 3 sub-projects under the main parent Maven project. Client and Server sit on either side of a RabbitMQ messaging server. Server looks for notifications in different queues based on the implementations given.
Current Stable Release Version - 0.0.8
Current Development Version - 0.0.9-SNAPSHOT
To run the server, just run the Main.java file after setting the following mandatory properties in server.properties file. These values denote where your RabbitMQ Server is and how you intend to access it.
rabbitmq.username=
rabbitmq.password=
rabbitmq.ipaddress=
rabbitmq.port=
rabbitmq.management.port=
rabbitmq.vhost=
Then you can add these properties which are required for the default implemenentation for Email - MailNotifierImpl.java
queue.email.request=
queue.email.reply=
The main interface on the server side is Notifier.java which has methods :
/**
* Sends the appropriate notofication
*/
void sendNotification(NotificationRequest request) throws AvisException;
/**
* Consumes the Request from the Queue
* @throws AvisException
*/
void consumeRequestFromQueue() throws AvisException;
/**
* Sends the response back
*
* @param response
* @throws AvisException
*/
void sendResponse(NotificationResponse response) throws AvisException;
/**
* Sets the queue-name for request
* @param queueName
* @throws AvisException
*/
void setRequestQueueName(String queueName) throws AvisException;
/**
* Returns the queue name
* @return
* @throws AvisException
*/
String getRequestQueueName() throws AvisException;
/**
* Sets the queue-name for request
* @param queueName
* @throws AvisException
*/
void setReplyQueueName(String queueName) throws AvisException;
/**
* Returns the queue name
* @return
* @throws AvisException
*/
String getReplyQueueName() throws AvisException;
There is a Abstract Implementation of the common tasks like consuming the request in the file AbstractNotifier.java. This class's main job is to look for messages in the specific queues declared for each notification type and when the request is received, process it by calling sendNotification on a TaskExecutor instance.
Newer implementations of Notifier interface will be declared in app-context.xml.
A client is used by 3rd party applications to send the notifications. The project consists of an interface AvisClient.java which has methods:
/**
* Sends a notification request to the queue name set on the request
*
* @param request
* @throws AvisClientException
*/
public void sendNotification(NotificationRequest request) throws AvisClientException;
/**
* Sends a notification request to the queue name passed, ignoring the queue name set in the
* request
* @param queueName
* @param request
*
* @throws AvisClientException
*/
public void sendNotification(String queueName, NotificationRequest request) throws AvisClientException;
There is a DefaultAvisClientImpl class which is the implementation of this interface and can be used to send the notification, by auto wiring it once you have added the dependency. Sample code is given below:
Your Class
.....
@Autowired
private AvisClient avisClient;
....
....
//where you want to send
NotificationRequest request = new NotificationRequest();
request.setId(UUID.randomUUID().toString());
request.setNotificationType(NotificationType.EMAIL);
request.setQueueName("NAME OF THE EMAIL QUEUE SERVER IS LISTENING");
NotificationData<String, Serializable> requestData = new NotificationData<>();
EmailData data = new EmailData();
data.setTo(new String[] { "you@you.com" });
data.setSubject("You got Mail");
data.setText("I'll be Back");
data.setSentDate(new Date());
requestData.put(NotificationType.EMAIL.toString(), data);
request.setData(requestData);
avisClient.sendNotification(request);
The classes NotificationRequest, NotificationData and EmailData are part of the Domain project.
This project contains all the domain specific POJO classes which are used to transferd data from client to server and back. NotificationRequest is the class used to send a notification, with the data held in NotificationData class. NotificationData is an extension of Java HashMap and can hold any Serializable data against a key of type String.
EmailData is a POJO class which captures the Email information that needs to be send. This is then set on the NotificationData instance before sending the notification.
Running the maven release plugin, requires the user to have ssh_keys in his/her system as we have to access the Github Repo. Please see the link for generating ssh-keys.
To upgrade the version and cut a release build - run the following commands on command prompt
mvn release:prepare -DdryRun=true -Darguments="-DskipTests=true"
This will walk you through a dry run and you can view the temporary POMs it creates to verify you did everything correctly. It is not mandatory to do this, if you are confident. It also skips the test execution
mvn release:clean release:prepare -Darguments="-DskipTests=true"
This will actually commit a tag with non-snapshot versions of your project and also increment all your versions to the next release. So for example, if your current version is 0.0.1-SNAPSHOT, it will commit a tag with 0.0.1 version, and update the trunk POMs with 0.0.2-SNAPSHOT. Of course when using the prepare goal you are prompted for the release numbers and next release numbers. Please note, you need to add git command in the path to run this.
Finally deploy and perform the release by running the command :
mvn release:perform -Darguments="-DskipTests=true -Dmaven.javadoc.skip=true"
For this command to run successfully your Maven settings.xml should have the authentication information to loginto Nexus. Please add the <servers> entry in the xml
<servers>
<server>
<id>releases</id>
<username>USERNAME_FOR_NEXUS</username>
<password>PASSWORD_FOR_NEXUS</password>
</server>
</servers>
Issues with running in Windows
When running the above command in Windows, it hands after the git push. This is because of the ssh key passphrase not being entered. As a work around to this do the following on a command prompt.
Run the command from Git/bin folder
ssh-agent
After you run it, it outputs some environment variables that you need to set. For example:
SSH_AUTH_SOCK=/tmp/ssh-LhiYjP7924/agent.7924; export SSH_AUTH_SOCK;
SSH_AGENT_PID=2792; export SSH_AGENT_PID;
echo Agent pid 2792;
So, you need to place these in your environment:
C:\> set SSH_AUTH_SOCK=/tmp/ssh-LhiYjP7924/agent.7924
C:\> set SSH_AGENT_PID=2792
Then, you will need to add a passphrase for your particular key file. So, the command is:
ssh-add
This will prompt to enter the passphrase which you used to create ssh_keys
Enter passphrase for /c/Users/<windows_username>/.ssh/id_rsa:
Once entered you should see an Identity added message. Now, the agent knows the passphrase so that you will not be prompted to specify it anymore.
If you have multiple instances of command prompts, make sure that each command prompt has the appropriate SSH_AUTH_SOCK and SSH_AGENT_PID environment variables set. You can validate that this is working by running a command like ssh -v git@github.com and if you DO NOT get prompted for a passphrase, it is working!
Note that when you logoff, the ssh-agent will shut down and so when you log back in or restart your computer, you will need to repeat these steps.