CODEWITHSUNDEEP
javajsonweb-servicesnested-loops
jcobo1
jcobo1

Reputation: 1180

Building JSON with java overwrites values

I'm trying to represent some info from the database with a json, the json structure is created well but don't know why overwrittes the last record from the database. So on my json I just got the last value readed instead al the values.

To do this I use a ResultSet from the main values and an iteration. Inside this iteration I get the related information, so this data is nested on the json. that's my code:

JSONObject json = new JSONObject();
          ResultSet sections = null;
          ResultSet questions = null;
          JSONObject section = new JSONObject();
          JSONObject question = new JSONObject();
          Db d = new Db();


          d.makeJDBCConnection();
          sections = d.getSections();
          while(sections.next()){
              section.put("name", sections.getString("sectionName"));
              section.put("id", sections.getInt("id"));
              questions = d.getQuestions(sections.getInt("id"));
              while(questions.next()){
                  // id, statement
                  question.put("id", questions.getInt("id"));
                  question.put("statement", questions.getString("statement"));
                  section.put("questions", question);
              }
          }

          json.append("section", section);

          return Response.status(200).entity(json.toString()).build();

I checked the debug and I get all the records but on the json response I just get the last one result.

Upvotes: 1

Views: 111

Answers (2)

Pavneet_Singh
Pavneet_Singh

Reputation: 37404

1.) Initialize your section and question inside loop

2.) Add section into json inside outter while loop

JSONObject json = new JSONObject();
          ResultSet sections = null;
          ResultSet questions = null;
          JSONObject section = null;
          JSONObject question = null;
          Db d = new Db();


          d.makeJDBCConnection();
          sections = d.getSections();
          while(sections.next()){

              section = new JSONObject();
              // initialize new one inside every iteration

              section.put("name", sections.getString("sectionName"));
              section.put("id", sections.getInt("id"));
              questions = d.getQuestions(sections.getInt("id"));
              while(questions.next()){
                  // id, statement

                  question = new JSONObject();
                  // initialize new one inside every iteration

              question.put("id", questions.getInt("id"));
                  question.put("statement", questions.getString("statement"));
                  section.put("questions", question);
              }
          json.append("section", section);
          // ^^ add every created record 
          // should be inside the loop
          }

Upvotes: 3

Willis Blackburn
Willis Blackburn

Reputation: 8204

You're repeatedly updating the same "question" and "section" object. You should create a new "section" object each time through the "while(sections.next())" loop and same thing for "question."

Upvotes: 0

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