org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray

[Xsi jadu]

How do I solve this?


this is my issue:

Exception in thread "main" java.lang.ClassCastException: org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray
	at GenericMethods.TestData.main(TestData.java:28)

This is my code

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;


public class TestData {

	
	
	 @SuppressWarnings("unchecked")
	    public static void main(String[] args)
	    {
	        //JSON parser object to parse read file
	        JSONParser jsonParser = new JSONParser();
	         
	        try (FileReader reader = new FileReader("C:/temp/TestData.json"))
	        {
	            //Read JSON file
	            Object obj = jsonParser.parse(reader);
	 
	            JSONArray employeeList = (JSONArray) obj;
	            System.out.println(employeeList);
	             
	            //Iterate over  array
	            employeeList.forEach( emp -> parseTestData( (JSONObject) emp ) );
	 
	        } catch (FileNotFoundException e) 
	        {
	            e.printStackTrace();
	        } catch (IOException e) 
	        {
	            e.printStackTrace();
	        } catch (ParseException e) 
	        {
	            e.printStackTrace();
	        }
	    }
	 
	 
	 private static void parseTestData(JSONObject employee)
	    {
	        //Get employee object within list
	        JSONObject testDataObject = (JSONObject) employee.get("Transaction");
	         
	        
	        String description = (String) testDataObject.get("description");   
	        System.out.println(description);
	         
	     
	        String conr = (String) testDataObject.get("Co-no"); 
	        System.out.println(conr);
	         
	        
	        String project = (String) testDataObject.get("Project");   
	        System.out.println(project);
	    }
}

Let me know if you need details

xsi

[Stephan van Hulst]

Well, at some point you've read a JSONObject from your input, and you're casting it to a JSONArray. A JSONArray is not a JSONObject.

Can you show us the input you're trying to parse?

[Xsi jadu]

Thank you I solved it

around my Object inside the JSON I forgot

[​]

[Stephan van Hulst]

I'm glad you figured it out, and thanks for reporting back to us with the answer. Have a cow!

[Rahul Vishwa]

Can you please give the input json file and how you solved this?

[Tamil Eniyan]

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

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


public class RWJson
{

@SuppressWarnings("unchecked")
public static void main(String[] args)
{

File parentDir = new File("C://Users//sta2002//Downloads//2022-09-02_81450");

File elements[] = parentDir.listFiles();
for(File element: elements)
{
//System.out.println(element);
File child = new File(element +"//TestResult");
System.out.println(child);

JSONParser jsonParser = new JSONParser();
       
      try(FileReader reader = new FileReader(child +"//statistics.json"))
      {
       
           //Read JSON file
          Object obj = jsonParser.parse(reader);

           JSONArray elementList = (JSONArray) obj;
           System.out.println(elementList);
           
           //Iterate over employee array
           elementList.forEach( emp -> parseEmployeeObject( (JSONObject) emp ) );
      }catch (FileNotFoundException e) {
           e.printStackTrace();
       } catch (IOException e) {
           e.printStackTrace();
       } catch (ParseException e) {
           e.printStackTrace();
       }

}
}



public static void parseEmployeeObject(JSONObject employee)
   {
       //Get employee object within list
       JSONObject employeeObject = (JSONObject) employee.get("Total");
       
       //Get employee first name
       String firstName = (String) employeeObject.get("meanResTime");    
       System.out.println(firstName);
       
       //Get employee last name
       String lastName = (String) employeeObject.get("throughput");  
       System.out.println(lastName);
       
   }

}



I'm also getting the same kind of error.
Can you tell me how to solve this?

[Frank Farkel]

I know this is 5y old, but it is astounding how few online code examples actually work to go from JSON to CSV.

Although this does look like a path/jar issue in the stacktrace, it was in the source, as the OP pointed out. But they didn't explain in a way that is useful.

This is from an API, and will cause the error:

{
    "endpoint": "Global Market Open & Close Status",
    "markets": [ <--- note
        {
            "market_type": "Equity",
            "region": "United States",
            "primary_exchanges": "NASDAQ, NYSE, AMEX, BATS",
            "local_open": "09:30",
            "local_close": "16:15",
            "current_status": "closed",
            "notes": ""
        },
        {
            "market_type": "Equity",
            "region": "Canada",
            "primary_exchanges": "Toronto, Toronto Ventures",
            "local_open": "09:30",
            "local_close": "16:00",
            "current_status": "closed",
            "notes": ""
        },
        { ...
    ]    <--- note
}

The above failed. When I simply wrapped the entire contents in a pair of brackets ("[ ...]"), though, it was all a single line, not discernable as CSV.

However, when I trimmed the characters before AND after the existing outer brackets, like this:

[
        {
            "market_type": "Equity",
            "region": "United States",
            "primary_exchanges": "NASDAQ, NYSE, AMEX, BATS",
            "local_open": "09:30",
            "local_close": "16:15",
            "current_status": "closed",
            "notes": ""
        },
        {
            "market_type": "Equity",
            "region": "Canada",
            "primary_exchanges": "Toronto, Toronto Ventures",
            "local_open": "09:30",
            "local_close": "16:00",
            "current_status": "closed",
            "notes": ""
        }, 
        } ...
]

joy.

No header values, but that is a separate issue. To help those running recent java, here is a snippet that works:

import com.opencsv.CSVWriter;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;

public class JsonToCsvConverter {
    
	public static void convertFile(String inJson, String outCsv) {
        JSONParser parser = new JSONParser();

        try (FileReader reader = new FileReader(inJson)) {
            Object obj = parser.parse(reader);
        	//var obj = parser.parse(reader);
            
            JSONArray jsonArray = (JSONArray) obj;
            
            Writer writer = new FileWriter(outCsv);
            CSVWriter csvWriter = new CSVWriter(writer);
            
            // Assuming each JSON object is a flat structure
            for (Object o : jsonArray) {
                JSONObject jsonObject = (JSONObject) o;
                List<String> data = new ArrayList<>();
                
                for (Object key : jsonObject.keySet()) {
                    data.add(String.valueOf(jsonObject.get(key)));
                }
                
                csvWriter.writeNext(data.toArray(new String[0]));
            }
            
            csvWriter.close();
            System.out.println("JSON has been converted to CSV successfully.");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

HTH

I was on here for a million years when it was the java ranch... starting over.. oh well!