Join Alex Theedom for an in-depth discussion in this video Write JSON data, part of JSON Processing with Java EE.
- [Instructor] Okay, so we're going to generate a string of JSON data, just as we did with the object model. And by using the same JSON data. If you want to follow along with this example, open up the streaming example three class file from the exercise folder. As before, we're going to use a string writer. This makes it easy to test, but you can use any writer or output stream instance, depending on the requirements. Now, because there is a lot of JSON data to write, I'm going to copy and paste a code from a file in the exercise files associated with this lesson.
I'm going to copy the entire write JSON stream to string method. So firstly, we start the construction of the JSON object by calling the write start object on the generator instance. Then, we call the write method for as many times as there are elements in the object. If an element is an array, we call the write start array method. And we continue calling write for each element in the array until the end. When we called write end, in order to signal that this is the end of the array.
Then we continue calling the appropriate write method to add further keys and properties. Then, at the end, we call the write end method to signal that we have finished writing. And then we close the generator and return the generated value. Don't forget to call the close method on the generator in order to close the resource. Now the code is written, let's jump to the unit test and write the code that asserts that we have constructed the JSON object correctly. And the code that we're going to write here is to simply assert that the JSON string that's created by our generator is equal to the JSON string we have here in our class.
So, we assert that the JSON string is equal to our JSON string here. So, let's execute the unit test and check to see if this works. And yes, the unit test passes. So, we are sure that the JSON object has been written correctly.
In this course, discover how to use the Java Enterprise Edition (EE) JSON-Processing API. With its two programming models, JSON-Processing is one of the simplest ways to generate, query, and parse JSON data, and you'll find that implementing it in your projects is quick and easy. Join Alex Theedom as he covers an array of topics, including how to use both the object model and the streaming model, how to traverse a JSON structure, and how to parse JSON data using the extensive builder APIs. When you wrap up this course, you'll be ready to develop with this essential and powerful API.
- Working with JSON and Java
- JSON-Processing API features
- The Java EE JSON object model
- Creating a model from a JSON string
- Building a JSON model
- Traversing the JSON model
- Outputting the JSON model to a data stream
- Parsing and writing JSON data