Build Presto-Connected Web Apps in Servoy

Servoy is a rapid application development and deployment platform. When paired with the CData JDBC Driver for Presto, users can build Presto-connected apps that work with live Presto data. This article describes how to connect to Presto from Servoy and build a simple web app to display and search Presto data.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live Presto data. When you issue complex SQL queries to Presto, the driver pushes supported SQL operations, like filters and aggregations, directly to Presto and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying lets you work with Presto data using native data types.

Connect to Presto in Servoy Developer

To build Presto-connected apps, you need to first create a data provider in Servoy Developer using the CData JDBC Driver for Presto.

1. Install the JDBC Driver.
2. Copy the JDBC Driver JAR file. (cdata.jdbc.presto.jar) to the /application_server/drivers/ directory in the installation directory for Servoy.
3. Open Servoy Developer.
4. In the Solution Explorer, right-click Database Server (under Resources) and choose "Connect to existing database" -> "empty."
   1. Name the server.
   2. Click to show the advanced server settings.

      • Set the URL, for example: jdbc:presto:Server=127.0.0.1;Port=8080;

        Built-In Connection String Designer

        For assistance in constructing the JDBC URL, use the connection string designer built into the Presto JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

        java -jar cdata.jdbc.presto.jar

        Fill in the connection properties and copy the connection string to the clipboard.

        Set the Server and Port connection properties to connect, in addition to any authentication properties that may be required.

        To enable TLS/SSL, set UseSSL to true.

        Authenticating with LDAP

        In order to authenticate with LDAP, set the following connection properties:

        • AuthScheme: Set this to LDAP.
        • User: The username being authenticated with in LDAP.
        • Password: The password associated with the User you are authenticating against LDAP with.

        Authenticating with Kerberos

        In order to authenticate with KERBEROS, set the following connection properties:

        • AuthScheme: Set this to KERBEROS.
        • KerberosKDC: The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
        • KerberosRealm: The Kerberos Realm used to authenticate the user with.
        • KerberosSPN: The Service Principal Name for the Kerberos Domain Controller.
        • KerberosKeytabFile: The Keytab file containing your pairs of Kerberos principals and encrypted keys.
        • User: The user who is authenticating to Kerberos.
        • Password: The password used to authenticate to Kerberos.
      • Select the Driver class you just copied, for example, cdata.jdbc.presto.PrestoDriver

Build a Presto-Connected Web App

Once you have configured the connection to Presto in the Servoy Developer resources, you are ready to build apps with access to live Presto data.

Create a New Solution

1. In the Server Explorer, right-click "All solutions" and select "Create new solution."
2. Name the solution.
3. Select the checkbox to include the "search" module.
4. Click "Finish."

Create a New Form

Right-click "Forms" and select "Create new form."

1. Name the form.
2. Select a Datasource.
3. Set the type (e.g., Simple) and click "Finish."

Add a Data Grid to the Form

1. Drag a Data Grid component (from Servoy NG-Grids) onto the form.

2. Drag a column component onto the Data Grid and set the "dataprovider" property for each column component to a column from the Presto "table" (e.g., FirstName from the Customer table).

   Continue adding columns as desired.

Add Searching to the App

Note that the "svySearch" extension is required to add search functionality (included by default when you create a new solution). If you did not add the extension when you created the solution or you are modifying an existing solution, you can add the search module by right-clicking Modules (in the solution) and selecting "Add Module." Select "svySearch" and click "OK."

1. Drag a Text Field component onto the Form.
2. Right-click the Form and select "Open in Script Editor."
3. Create a new variable (JavaScript) to hold the search value:

   var searchText = '';
   

4. Back on the Form, in the Text Field properties:
   1. Set the "dataprovider" property to the Form variable you just created.
   2. Double-click to add a method for the onAction event.
   3. Click to create the method in "Form," name the method (e.g., onEnter), and click "Create private."
   4. Click "OK & Show."
5. Add the following JavaScript to the JavaScript file to use the Servoy framework to implement searching bound data based on the text in the Text Field:

   var search = scopes.svySearch.createSimpleSearch(foundset).setSearchText(searchText);
   search.setSearchAllColumns();
   search.loadRecords(foundset);
   

Save and Launch the App

Save the form and JavaScript file, then click Run -> Launch NGClient to start the web app.

Download a free, 30-day trial of the CData JDBC Driver for Presto and start building Presto-connected apps with Servoy. Reach out to our Support Team if you have any questions.