I'm trying to read a json file, but compiler says, Parser cannot be resolved JAVA

Question

I've downloaded and added a json-simple.jar to my project in eclipse. The only problem is with the Parser, Eclipse says "parser cannot be resolved". While the JSONObject and JSONArray are working just fine.

I get the error when trying to read the file :

JSONParser parser = new JSONParser();
JSONArray jArray = (JSONArray) parser.parse(new FileReader("comments.json"));

imported as follows :

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

I've just started using json, so i might be missing something.

The comments.json file is of this format :

{
"postId": 1,
"id": 1,
"name": "id labore ex et quam laborum",
"email": "Eliseo@gardner.biz",
"body": "laudantium enim quasi est"
}

You could try other JSON libraries like Jackson or Gson. `json-simple` is a little... too simple — OneCricketeer, Nov 14 '16 at 19:36
Re: "Eclipse says 'parser cannot be resolved'": How does it say that? Is this a compile error, or a runtime error? In either case, please post the *complete, exact* error. — ruakh, Nov 14 '16 at 19:44
It's a compilation error! "Exception in thread "main" java.lang.Error: Unresolved compilation problem: parser cannot be resolved" — omlfc be, Nov 14 '16 at 19:49
Hovering over org.json.simple.parser.JSONParser, gives the following note: "This element neither has attached source nor attached javadoc", the problem could be with the .jar — omlfc be, Nov 14 '16 at 19:52

score 0 · Answer 1 · answered Nov 14 '16 at 20:00

I haven't tested it but as your json file has only one object, I prefer to use JSONObject instead of JSONArray:

    Object obj = parser.parse(new FileReader("comments.json"));
    JSONObject jsonObject = (JSONObject) obj;
    String name = (String) jsonObject.get("name");
    System.out.println(name);

score 0 · Accepted Answer · answered Nov 14 '16 at 20:05

I personally prefer the Jackson library so I'm not as familiar with JSON.simple. Did you consider creating a ContainerFactory() for the parser? http://juliusdavies.ca/json-simple-1.1.1-javadocs/org/json/simple/parser/ContainerFactory.html

Also, your "comment.json" is just a JSONObject(), so no need in giving in the extra overhead of JSONArray()

Maybe give this a shot:

ContainerFactory cf = new ContainerFactory();
Map jsonContainer = cf.createObjectContainer(); 

JSONParser parser = new JSONParser();
JSONObject jObj = (JSONObject) parser.parse(new FileReader("comments.json"), jsonContainer);

I'm trying to read a json file, but compiler says, Parser cannot be resolved JAVA

2 Answers2