How to fluently build JSON in Java?

Question

I\'m thinking of something like:

String json = new JsonBuilder()
  .add(\"key1\", \"value1\")
  .add(\"key2\", \"value2\")
  .add(\"key3\", new JsonBuilder()         


        

Answer 1

You can use one of Java template engines. I love this method because you are separating your logic from the view.

Java 8+:

  com.github.spullara.mustache.java
  compiler
  0.9.6

Java 6/7:

  com.github.spullara.mustache.java
  compiler
  0.8.18

Example template file:

{{#items}}
Name: {{name}}
Price: {{price}}
  {{#features}}
  Feature: {{description}}
  {{/features}}
{{/items}}

Might be powered by some backing code:

public class Context {
  List items() {
    return Arrays.asList(
      new Item("Item 1", "$19.99", Arrays.asList(new Feature("New!"), new Feature("Awesome!"))),
      new Item("Item 2", "$29.99", Arrays.asList(new Feature("Old."), new Feature("Ugly.")))
    );
  }

  static class Item {
    Item(String name, String price, List features) {
      this.name = name;
      this.price = price;
      this.features = features;
    }
    String name, price;
    List features;
  }

  static class Feature {
    Feature(String description) {
       this.description = description;
    }
    String description;
  }
}

And would result in:

Name: Item 1
Price: $19.99
  Feature: New!
  Feature: Awesome!
Name: Item 2
Price: $29.99
  Feature: Old.
  Feature: Ugly.

• mustache: https://github.com/spullara/mustache.java
• But there is also Jinja: https://github.com/HubSpot/jinjava
• And carrot: https://github.com/codeka/carrot