Configure the CData JDBC Driver for JSON in a Connection Pool in Tomcat

The CData JDBC Drivers support standard JDBC interfaces to integrate with Web applications running on the JVM. This article details how to connect to JSON services from a connection pool in Tomcat.

Connect to JSON Services through a Connection Pool in Tomcat

1. Copy the CData JAR and CData .lic file to $CATALINA_HOME/lib. The CData JAR is located in the lib subfolder of the installation directory.
2. Add a definition of the resource to the context. Specify the JDBC URL here.

   See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models JSON APIs as bidirectional database tables and JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

   After setting the and providing any authentication values, set to more closely match the data representation to the structure of your data.

   The property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

   • Document (default): Model a top-level, document view of your JSON data. The data provider returns nested elements as aggregates of data.
   • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
   • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

   See the Modeling JSON Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.json.jar
   

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

   👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)
   

   You can see the JDBC URL specified in the resource definition below.

   <Resource name="jdbc/json" auth="Container" type="javax.sql.DataSource" driverClassName="cdata.jdbc.json.JSONDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:json:URI=C:/people.json;DataModel=Relational;" maxActive="20" maxIdle="10" maxWait="-1" />
   

   To allow a single application to access JSON services, add the code above to the context.xml in the application's META-INF directory.

   For a shared resource configuration, add the code above to the context.xml located in $CATALINA_BASE/conf. A shared resource configuration provides connectivity to JSON for all applications.

3. Add a reference to the resource to the web.xml for the application.

    JSON services JSP
    jdbc/JSON
    javax.sql.DataSource
    Container
   
   

4. Initialize connections from the connection pool:

   Context initContext = new InitialContext();
   Context envContext = (Context)initContext.lookup("java:/comp/env");
   DataSource ds = (DataSource)envContext.lookup("jdbc/JSON");
   Connection conn = ds.getConnection();
    

More Tomcat Integration

The steps above show how to connect to JSON services in a simple connection pooling scenario. For more use cases and information, see the JNDI Datasource How-To in the Tomcat documentation.