Connect to JSON in SpagoBI

The CData JDBC Driver for JSON enables you to connect to live JSON services from business intelligence and data mining tools that support the JDBC standard. This article shows how to integrate JSON services into a report in SpagoBI Studio and host it on SpagoBI Server.

• Deploy the Driver in SpagoBI Server
• Create a Report in SpagoBI Studio
• Host JSON Reports on SpagoBI Server

Deploy the JDBC Driver in SpagoBI Server

Follow the steps to create a JDBC data source for JSON in SpagoBI Server.

1. Copy the driver JAR into %CATALINA_BASE%/lib. These files are located in the lib subfolder of the installation directory.

2. Add a JSON driver resource to the context. The following resource definition can be added to the GlobalNamingResources element in server.xml: <Resource name="jdbc/json" auth="Container" type="javax.sql.DataSource" driverclassname="cdata.jdbc.json.JSONDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" maxactive="20" maxidle="10" maxwait="-1"/>

3. Add the following resource link to give access to Web applications. For this article, add the following line to META-INF\context.xml for SpagoBI. <ResourceLink global="jdbc/json" name="jdbc/json" type="javax.sql.DataSource"/>
4. Restart the server.

After adding the driver to the resources for the SpagoBI server, add the data source: In SpagoBI, click Resources -> Data Source -> Add and enter the following information:

• Label: Enter a unique identifier for the driver.
• Description: Enter a description for the driver.
• Dialect: Select Default Dialect.
• Read Only: Select the read-only option. This option determines whether the data source is the default database to save datasets created by the end user.
• Type: Select JDBC.
• URL: Enter the JDBC URL using the required connection string properties:

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

  The DataModel 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.

  A typical JDBC URL is below:

  jdbc:json:URI=C:/people.json;DataModel=Relational;
• Driver: Enter the class name for the driver: cdata.jdbc.json.JSONDriver

Create Reports in SpagoBI Studio

Follow the steps below to populate reports based on JSON services in SpagoBI Studio. You will create a dataset that populates a chart with the results of an SQL query. In the next section, you will host this report on SpagoBI Server.

First, you will need to connect to JSON services from a report in SpagoBI Studio:

1. In SpagoBI Studio, click File -> New -> Project and select Report Project in the Business Intelligence and Reporting Tools folder.
2. Click File -> New -> Report and select Blank Report.
3. In the Data Explorer view, right-click Data Sources and click New Data Source.
4. Select JDBC Data Source and enter a name for the data source.
5. Click Manage Drivers and click Add to add the driver JAR, cdata.jdbc.json.jar. The driver JAR is located in the lib subfolder of the installation directory.
6. In the Driver Class menu, select the driver class, cdata.jdbc.json.JSONDriver.
7. In the Database URL box, enter the JDBC URL. A typical JDBC URL is below: jdbc:json:URI=C:/people.json;DataModel=Relational; See the "Getting Started" chapter of the driver help for a guide to obtaining the required connection properties.

After you have connected to JSON services, create a dataset that contains the results of an SQL query:

1. Right-click the DataSet folder and click New Data Set. Select the JDBC data source for JSON and enter a name for the dataset.
2. Build the SQL query. In this example, this query will be used to add a chart to the dashboard. For example: SELECT [people].[personal.age] AS age, [people].[personal.gender] AS gender, [people].[personal.name.first] AS first_name, [people].[personal.name.last] AS last_name, [vehicles].[model], FROM [people] JOIN [vehicles] ON [people].[_id] = [vehicles].[people_id]

You can use the dataset to populate report objects. Follow the steps below to create a chart.

1. In the Palette view, drag a chart onto the canvas.
2. In the Select Chart Type tab, select a bar chart.
3. In the Select Data tab, click the Use Data From option and select the JSON data set from the menu.
4. Drag [ personal.name.first ] from the table to the series for the x-axis.
5. Drag [ personal.name.last ] from the table to the series for the y-axis.

Host JSON Reports on SpagoBI Server

Follow the steps below to host documents based on live JSON services on SpagoBI Server. You will use the report you created in the previous section as a template. To enable report users to access the live data, create placeholder parameters to be replaced by the JSON JDBC data source on the server:

1. If you have not already done so, open the Report Design perspective in SpagoBI Studio.
2. In the Data Explorer view, right-click the Report Parameters folder and click New Parameter. Add the url parameter and assign an empty value to it. This parameter is a placeholder for the JDBC data source on the SpagoBI Server.
3. Right-click the JSON data source and click Edit.

4. In the Property Binding node, set the JDBC Driver URL binding property to the url parameter: Click the box for the property. In the Category section, select Report Parameters. Select All in the Subcategory section and double-click the parameter.

   You can also enter the following in the JavaScript syntax:

   params["url"].value

Next, create a new document for the report on SpagoBI Server.

1. In SpagoBI Server, click Documents Development -> Create Document -> Generic Document. The Document Details page is displayed.
2. To create the document, enter the following:
   • Label: Enter a unique identifier for the document.
   • Name: Enter a user-friendly name for the document.
   • Type: Select Report from the menu.
   • Engine: Select BIRT Report Engine.
   • Data Source: Select the JSON Data Source you created in Create a JDBC Data Source for JSON in SpagoBI Server.
3. In the Show Document Templates section, select the folder where you want the document to be stored.

4. In the Template section, click Choose File. Navigate to the folder containing your report project. Select the .rptdesign file.

   Note: You can find the path to the project in the project properties.

5. Click the Save button.

When you run the report on the server, the placeholder url parameter is replaced with the JDBC URL defined on the server.