Parse JSON multiple objects

Question

I am trying to parse the below json but unable to do that as stack over flow error comes in.

Here is the JSON -

[{
    "Class": "1",
    "school": "test",
    "description": "test",
    "student": [
        "Student1",
        "Student2"
    ],
    "qualify": true,
    "annualFee": 3.00
}]

Here is the code which is failing currently.

String res  = cspResponse.prettyPrint();
org.json.JSONObject obj = new org.json.JSONObject(res);
org.json.JSONArray arr = obj.getJSONArray(arrayName);
String dataStatus=null;

for (int i = 0; i < arr.length(); i++) {
    dataStatus = arr.getJSONObject(i).getString(key);
    System.out.println("dataStatus is \t" + dataStatus);
}

Usecases are:

To get the value key "class"
Get the value from Student
Get the value from school

I appreciate your help.

update-1 Code more info on stack trace updated with below details. cls = 1

error- org.json.JSONException: JSONObject["student "] not a string.

Stack trace-

public String getString(String key) throws JSONException {
        Object object = this.get(key);
        if (object instanceof String) {
            return (String) object;
        }
        throw new JSONException("JSONObject[" + quote(key) + "] not a string.");
    }

When I ran the code with the below answers, here its failing for student is not a string.

The answers I used from first two comments and both have the same error. I appropriate your help.

yet same. So I have updated question with update-1 with stack trace. — Sobhit Sharma
– Sobhit Sharma, Commented Oct 1, 2019 at 11:52

eparovyshnaia · Accepted Answer · 2019-10-01 06:55:23Z

2

Your json fragment is invalid - the last comma breaks the parsing. But the rest of the code is quite workable.

    String res = "[\n" +
            "    {\n" +
            "        \"Class\": \"1\",\n" +
            "        \"school\": \"test\",\n" +
            "        \"description\": \"test\",\n" +
            "        \"student\": [\n" +
            "            \"Student1\",\n" +
            "            \"Student2\"\n" +
            "        ],\n" +
            "        \"qualify\": true,\n" +
            "        \"annualFee\": 3.00\n" +
            "       }\n" +
            "]";

    JSONArray arr = new JSONArray(res);
    for (int i = 0; i < arr.length(); i++) {
        JSONObject block = arr.getJSONObject(i);
        Integer cls = block.getInt("Class");
        System.out.println("cls = " + cls);
        Object school = block.getString("school");
        System.out.println("school = " + school);
        JSONArray students = block.getJSONArray("student");
        System.out.println("student[0] = " + students.get(0));
        System.out.println("student[1] = " + students.get(1));
    }

should output

cls = 1
school = test
student[0] = Student1
student[1] = Student2

answered Oct 1, 2019 at 6:55

eparovyshnaia

1,0918 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Sobhit Sharma Over a year ago

I am getting error when, its assigned res with json array.

eparovyshnaia Over a year ago

Fix you json source first - the last comma in < "annualFee": 3.00,> phrase make the parsing fail

Sobhit Sharma Over a year ago

I fixed it, yet same.

eparovyshnaia Over a year ago

Copy the comment's code and paste it to become your main method's body. It is compilable, runnable and produce the output listed here. If then you have an error - post more details here.

Sobhit Sharma Over a year ago

yet same. So I have updated question with update-1 with stack trace.

|

Alireza Bideli · Accepted Answer · 2019-10-01 07:40:42Z

1

Your JSON reponse root is array but you consider your JSON response as JSON object

Changing your parsing json code as below

String res=cspResponse.prettyPrint();
    org.json.JSONArray arr = new org.json.JSONArray(res);
    String dataStatus=null;
    for (int i = 0; i < arr.length(); i++) {
        org.json.JSONObject obj=arr.getJSONObject(i);
        dataStatus = obj.getString(key);
        System.out.println("dataStatus is \t" + dataStatus);
        String schoolName = org.getString("school");
        System.out.println("school => " + schoolName);
        org.json.JSONArray students = obj.getJSONArray("student");
        System.out.println("student[0] = " + students.get(0));
        System.out.println("student[1] = " + students.get(1));
    }

edited Oct 1, 2019 at 7:40

answered Oct 1, 2019 at 6:55

Alireza Bideli

8744 gold badges9 silver badges33 bronze badges

2 Comments

Sobhit Sharma Over a year ago

It says org.json.JSONException: JSONObject["student"] not a string.

Sobhit Sharma Over a year ago

yet same. So I have updated question with update-1 with stack trace.

Ganesh A · Accepted Answer · 2019-10-01 07:00:55Z

0

    You can use simple JSONObject class and Simple JSONParser for parsing the JSON.

     1. Parse the JSON. 

          org.json.simple.JSONParser parser = new org.json.simple.JSONParser();
          org.json.simple.JSONObject parsedJSON = parser.parse(inputJSON);

     2. To get class: 

          String class = parsedJSON.get("Class");

     3. To get Students: 

          org.json.simple.JSONArray studentArray = parsedJSON.get("student");

    4. To Get School: 

         String school = parsedJSON.get("school");

    After the above steps, you can run a for-loop to print the class and students.

answered Oct 1, 2019 at 7:00

Ganesh A

162 bronze badges

Collectives™ on Stack Overflow

Parse JSON multiple objects

3 Answers 3

6 Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

6 Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related