Creating JMS Listeners

Follow these steps to create a JMS listener:

  1. If this is the first time you create a JMS listener on this Denodo server, install the client jars of the JMS server you are going to use. The page Installing the JMS Connectors to Create JMS Listeners and Web services with SOAP over JMS of the Installation Guide explains how to do this.

  2. Click JMS Listener on the File > New menu or right-click the Server Explorer and click JMS Listener on the New menu.

  3. Click On to enable the listener. If you click Off, the listener will be created but it will be disabled.

  4. Select the VDP user name that Virtual DataPort will use to execute the queries received by the listener. The user selected has to be a local user. It has to be a user created in Virtual DataPort. The page Privileges Required explains in detail the type of users you can select in this list.

    For example, if we have two users:

    1. admin: is an “administrator” or a user promoted to “local administrator” of the database so it can access any view of the database.

    2. user1: is a “normal user” that only has EXECUTE privileges over this database.

      If you select the user “admin”, the listener will be able to execute any query. However, if you select “user1”, the CREATE, DROP, INSERT, UPDATE and DELETE queries will fail because “user1” only has EXECUTE privileges.

  5. If you want to use a parameterized query, select the JMS messages contain the value of… check box and enter the query in the box below.

    As we have explained in the previous section, when using this option, the string @JMSEXPRESSION is replaced at runtime by the value received from the JMS server.

  6. Select Output XML or JSON if you want the output of the listener to be an XML document or a JSON document.

  7. Destination is the name of the queue or topic that Virtual DataPort will subscribe to, waiting for requests.

    Depending on the vendor of the JMS server, you might have to create the JMS destination, or it will be created automatically when the listener tries to subscribe to it.

  8. Select Queue or Topic.

  9. Reply to is the name of the JMS queue or topic where the responses will be sent to.

    If not empty, the responses will always be sent to this destination, even if the JMS message contains the “Reply to” field.

    If empty, the responses will be sent to the destination indicated in the “Reply to” field of the JMS request. If the JMS request does not have this field either, the Server will not send any response.

    If Ignore reply to is selected, the listener will never send a response.

  10. User name and Password are the credentials to connect to the JMS server.

  11. Select Split the response in several messages and enter a value in Max. number of rows in each message to enable chunking in the responses.

  12. JMS vendor. Select Generic if the vendor of the JMS server is not in the list and it can be accessed via JNDI. In this case, you have to provide the appropriate JNDI connection properties (appendix JMS Connection Details: JNDI Properties contains a list of the required JNDI properties for the most popular JMS vendors).

  13. In the Metadata tab, you can set the folder where the JMS listener will be stored and provide a description for it.

Creating a new JMS listener

Creating a new JMS listener

After creating the listener, you can open the JMS Listener Status dialog (Tools > JMS Listeners menu) to see the list of existing JMS listeners.

List of existing JMS listeners

List of existing JMS listeners

You can enable / disable a JMS listener by selecting its check box beside the status of the listeners and clicking on Enabled selected and Disable selected.

To delete a listener, right-click on it in the Server Explorer and click Drop.

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