Topic outline

• Interacting with Data In Java Using Multiple Data Models

  Interacting with Data In Java Using Multiple Data Models

  Try out the multi-model architecture of InterSystems IRIS® data platform, which lets you write code using the data models that best fit each task in your application. Multi-model access in InterSystems IRIS is possible due to an underlying data structure called globals, which allow you to interact with your data directly. These provide flexible data access while avoiding data duplication.

  With Java, you can interact with your data using globals, connecting to InterSystems IRIS with the Native API. Another option is to connect with JDBC and use industry-standard SQL to access your data. In this case, data is modeled as a relational table. You can also use XEP or Hibernate to treat the same data as objects, without the need for additional object-relational mapping software.

  The same capabilities exist whether you are programming in InterSystems ObjectScript or using one of the external language APIs. If you are more familiar with a different language, try this exercise in Python, ObjectScript, or .NET.

  Watch the video and try the exercise below!
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  Try It

  Try It

  In the tasks below, you will interact with a set of airport data in multiple ways. You will create the data using an object-oriented model, then retrieve that data via SQL. Finally, you will use globals to create a custom data structure to store route information.

  Click the button below to launch an InterSystems Learning Lab for use in the exercise.

  Note:

  You can follow along with these instructions on your own server instead of using the Learning Lab. To do so, first download the code sample from GitHub and compile it on your InterSystems server. You should use your own InterSystems Terminal and IDE. You must also have JDK8 installed.

  • You must be logged in to launch an InterSystems IRIS instance.

    • Log in with your existing account.
    • Don't have an InterSystems account? Create a new account.
  • Connect to InterSystems IRIS
    

    First, edit the connection information in the Java file to allow it to connect to your InterSystems IRIS instance.

    1. Open the InterSystems Learning Lab IDE using the link in the launcher above.
    2. Using the file explorer on the left, open the file shared/quickstarts-multimodel-java/src/multimodelQS.java.
    3. On line 31, change the value of the IP address from localhost to the InterSystems IP provided when you launch the Learning Lab.
    4. On the next line, change the value of the port to the InterSystems SuperServer Port provided.
    5. Save the file multimodelQS.java.
  • Use objects and SQL side-by-side

    1. Inspect the code in multimodelQS.java.
       • The populateAirports() method populates five objects and saves them to the database.
       • The getAirports() method runs an SQL query and returns all airports, printing them to the screen.
    2. Using the built-in terminal in the IDE, navigate to the folder containing multimodelQS.java:

       cd quickstarts-multimodel-java/src

    3. Compile and run multimodelQS.java, which executes the populateAirports() and getAirports() methods: Begin code:

       javac -cp ".:../lib/intersystems-jdbc-3.7.1.jar:../lib/intersystems-xep-3.2.1.jar" multimodelQS.java

       End code. Begin code:

       java -cp ".:../lib/intersystems-jdbc-3.7.1.jar:../lib/intersystems-xep-3.2.1.jar" multimodelQS

       End code

    It is possible to accomplish these two tasks using only objects or SQL to populate and access the data. However, using the multi-model capabilities of InterSystems IRIS, you can choose the best data model according to the task—optimizing both developer time and application performance.

  • Create a custom data structure with globals

    In your work with airport data, a new question has come up: you need to get information about routes between the airports stored in your database. Fortunately, with InterSystems IRIS you can use globals to natively store data in a custom data structure, modifying the structure to fit your specific data. This allows you to handle the route information easily, even though it was not part of the initial schema design.

    1. In the IDE, return to multimodelQS.javaand locate the storeAirfare() and checkAirfare() methods.
       • The storeAirfare() method has been created to store route information to InterSystems IRIS.
       • The data structure used in this method does not use objects or an SQL table. Instead, it uses the global variable ^airport.
       • Similarly, check_airfare() accesses the ^airport global to return a particular route, if it exists.
    2. Uncomment lines 64-65 in multimodelQS.java and save the file.
    3. Compile and run the code again, and enter values to see if there are routes from BOS to AUS. You should find there are routes available. Begin code.

       javac -cp ".:../lib/intersystems-jdbc-3.7.1.jar:../lib/intersystems-xep-3.2.1.jar" multimodelQS.java

       End code. Begin code.

       java -cp ".:../lib/intersystems-jdbc-3.7.1.jar:../lib/intersystems-xep-3.2.1.jar" multimodelQS

       End code.
    4. Run it again and try BOS to LAX, which should return no available routes.

    You have now connected a sample Java application to InterSystems IRIS and explored the various APIs available to interact with data in different ways.

• What's Next?

  What's Next?

  • Start developing with Java and InterSystems IRIS using your preferred API (exercise, 5m).
  • Explore multiple data models with globals (exercise, 10m).
  • Learn how to build a server-side application (learning path, 2h).

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