Return servlet response as json data.

[sesmic]

I'm working on servlet registered on path & wanted to return its content in json data.
Currently, my servlet is fetching data from 

"/content/myproject/language-masters/en/jcr:content/root/container/container/componentname". Here values in component are injected via model & same used for servlet. I'm referring this blog. This is my code:

@Override
protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) {
try {
ResourceResolver resourceResolver = request.getResourceResolver();

Resource resource = resourceResolver.getResource("/content/myproject/language-masters/en/jcr:content/root/container/container/mycomponent");

ProductDetails model = resource.adaptTo(ProductDetails.class);

response.getWriter().print("Product Specs are =>\n\nProduct Name: " + model.getName() + "\nPhone Ram: " + model.getRam() + "\nLaptop OS: " + model.getOs() + "\nTV Screensize: "+ model.getSize() + "\nWatch Dial Shape: " + model.getShape() + "\nProduct Prices: "+ model.getPrice());

resourceResolver.close();
} catch

and its working good, displaying text. 

But for current requirement, I want to return this as json data(need necessary not to be in key:value pair, just json data anyway) in response. So, please tell me how can I do this?

[tb1687196]

Hi @sesmic ,

You can do it by jackson or Gson parsing. You will get many examples over internet about the process.

[sesmic]

Thanks for replying. Sorry, but I don't know how to use them. Can you give some hint please?

[Mohit_KBansal]

Check this sample code [1] 

[1] https://gist.github.com/nateyolles/d4ca683078efd60aa8ac 

[sesmic]

Thanks for the reply.
I can't understand about how can I adapt it to my code.

[Mohit_KBansal]

@sesmic Here is another simple example which you can follow [1], this example uses gson.

public class EmployeeServlet extends HttpServlet {

    private Gson gson = new Gson();

    @Override
    protected void doGet(
      HttpServletRequest request, 
      HttpServletResponse response) throws IOException {
        Employee employee = new Employee(1, "Emp name", "IT", 5000);
        String employeeJsonString = this.gson.toJson(employee);

        PrintWriter out = response.getWriter();
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        out.print(employeeJsonString);
        out.flush();   
    }
}

[1] https://www.baeldung.com/servlet-json-response

[arunpatidar]

Hi,

You can do json export from model or via public method expose json from model and access in servlet

https://experienceleague.adobe.com/docs/experience-manager-64/developing/components/json-exporter-co... 

[B_Sravan]

Hi @sesmic,

As suggested by @Mohit_KBansal, you can get your data in JSON, but are you using servlet just for that?
I would recommend using Sling Exporters to have your data in an easier way.

check this: https://experienceleague.adobe.com/docs/experience-manager-learn/foundation/development/develop-slin... 

Thanks,

Sravan

[sesmic]

Thanks all! I imported com.google.gson.Gson and added values to json (String myJsonString = this.gson.toJson(model);) then object out.print(myJsonString).

[HeenaMadan · Accepted solution]

You can use google.gson api to pass json in response. try this.

@Override
protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) {

ResourceResolver resourceResolver = request.getResourceResolver();

Resource resource = resourceResolver.getResource("/content/myproject/language-masters/en/jcr:content/root/container/container/mycomponent");

ProductDetails productDetails = ProductDetails.builder().id("component-id").name("modelname").build();

String jsonString = this.gson.toJson(productDetails);


PrintWriter out = response.getWriter();
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        out.print(jsonString);
        out.flush();
}

import lombok.Builder;
import lombok.Data;

import java.io.Serializable;

@Builder
@Data
public class ProductDetails implements Serializable {
    private int id;
    private String name;
}

If you don't want to use lombok then use entity class like this

public class ProductDetails {
	private String id;
        private String name;
    //Getters/Setters
    }

and ProductDetails product = new ProductDetails("component-id", "model name");

String jsonString = this.gson.toJson(product);