How do you return a JSON object from a Java Servlet

To return a JSON object from a Java Servlet, you can use the following steps:

  1. Add the following dependencies to your project's classpath:
  • The JSON library of your choice (e.g. Jackson, Gson, etc.)
  • The Servlet API library (e.g. javax.servlet-api)
  1. In your Servlet, use the JSON library to create a JSON object or array. For example, using Jackson:
ObjectMapper mapper = new ObjectMapper();
ObjectNode root = mapper.createObjectNode();
root.put("key", "value");
  1. Set the response content type to application/json:
response.setContentType("application/json");
  1. Write the JSON object or array to the response using the response.getWriter() method:
response.getWriter().write(root.toString());

That's it! Your Servlet should now return a JSON object in the response.

I hope this helps. Let me know if you have any questions.