Parsing JSON from HttpClient request using JSON.org parser

Question

I am trying to parse JSON using a Notes agent, JSON is fetched using Apache HttpClient.

Here is the code that return the JSON

import lotus.domino.*;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;

      Session session = getSession();
      AgentContext agentContext = session.getAgentContext();

      HttpClient client = HttpClientBuilder.create().build();
      HttpGet request = new HttpGet("http://api.acme.com/customer");
      request.addHeader("accept", "application/json");
      request.addHeader("Host", "api.acme.com");
      request.addHeader("X-Api-Version", "1.0");
      request.addHeader("Authorization", "Basic ...");

      HttpResponse response = client.execute(request);       

The JSON Looks like this.

[ 
  { 
    "id": 123456, 
    "insertDate": "2014-05-12T16:51:38.343", 
    "read": false, 
    "site": "acme.com", 
    "Email": "john.doe@acme.com", 
    "location": "/customer/1212?v=1.0" 
  } 
] 

I have tried to use JSONObject and JSONArray from JSON.org but could not get it to work I need some example code from the json.org package or other ways to parse the json.

Answer 1

You can get the JSON from the Entity in the HttpResponse using HttpResponse#getEntity. Once you have that, then just create a new JSONArray and iterate the array to access the values in your JSON object:

String json = IOUtils.toString(response.getEntity().getContent());
JSONArray array = new JSONArray(json);
for (int i = 0; i < array.length(); i++) {
    JSONObject object = array.getJSONObject(i);
    log.info("the id is {}", object.getInt("id"));
    log.info("the insertDate is {}", object.getString("insertDate"));
    log.info("read is {}", object.getBoolean("read"));
    log.info("the site is {}", object.getString("site"));
    log.info("the Email is {}", object.getString("Email"));
    log.info("the location is {}", object.getString("location"));
}

I saved the JSON in a JSONBlob at http://jsonblob.com/537a43bfe4b047fa2ef5f15d and created a unit test that requests that JSON:

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;
import org.json.JSONArray;
import org.json.JSONObject;
import org.junit.Test;

@Slf4j
public class JsonTest {
    @Test
    public void test() throws Exception {
        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet("http://jsonblob.com/api/jsonBlob/537a43bfe4b047fa2ef5f15d");
        request.addHeader("accept", "application/json");
        HttpResponse response = client.execute(request);
        String json = IOUtils.toString(response.getEntity().getContent());
        JSONArray array = new JSONArray(json);
        for (int i = 0; i < array.length(); i++) {
            JSONObject object = array.getJSONObject(i);
            log.info("the id is {}", object.getInt("id"));
            log.info("the insertDate is {}", object.getString("insertDate"));
            log.info("read is {}", object.getBoolean("read"));
            log.info("the site is {}", object.getString("site"));
            log.info("the Email is {}", object.getString("Email"));
            log.info("the location is {}", object.getString("location"));
        }
    }
}

And the output from running it is:

11:23:19.508 [main] INFO  JsonTest - the id is 123456
11:23:19.516 [main] INFO  JsonTest - the insertDate is 2014-05-12T16:51:38.343
11:23:19.516 [main] INFO  JsonTest - read is false
11:23:19.516 [main] INFO  JsonTest - the site is acme.com
11:23:19.516 [main] INFO  JsonTest - the Email is john.doe@acme.com
11:23:19.516 [main] INFO  JsonTest - the location is /customer/1212?v=1.0

I used the IOUtils class to convert the InputStream from the HttpResponse Entity, but this can be done anyway you like (and converting it like I did may not be the best idea depending on how big the JSON is).