replace substring from string in java

Question

I have the string hello Mr $name ur score is $value, What is the best way to get $name and $value part?

String json = "{\n" + "\"id\": 1,\n" + "\"data\":[\n" + "{\n"
            + "\"to\":123456789,\"name\":\"james\",\"value\":200\n" + "},\n" + "{\n"
            + "\"to\":123456789,\"name\":\"jhon\",\"value\":20\n" + "}]\n" + "}\n" + "";

Object obj = new JSONParser().parse(json);
            JSONObject jsonObject = (JSONObject) obj;
            long id = (long) jsonObject.get("id");
            JSONArray arrayOfdata = (JSONArray) jsonObject.get("data");
            JSONObject dataObject = new JSONObject();
            ArrayList<String> data = new ArrayList<>();
            for (String w : words) {
                if (w.contains("$"))
                    if (json.contains(w.substring(1))) {
                        data.add(w.substring(1));
                    }
            }
            for (int n = 0; n < arrayOfdata.size(); n++) {
                dataObject = (JSONObject) arrayOfdata.get(n);
                for (int j = 0; j < data.size(); j++) {
                    String msg = message.replace(data.get(j).toString(), dataObject.get(data.get(j)).toString());
                    String strNew = msg.replace("$", "");
                    logger.info("strNew " + strNew);
                }
            }

Result

Possible duplicate of [Java; String replace (using regular expressions)?](https://stackoverflow.com/questions/632204/java-string-replace-using-regular-expressions) — pringi, Oct 16 '18 at 12:12
What is your requirement. Your question is not clear. There is something you missed in the code u have posted. Please make it clear. — Sivaprasad, Oct 16 '18 at 12:29

Amit Kumar Lal · Accepted Answer · 2018-10-16T15:56:29.803

0

public static void main(String...strings) {     
    String inputString = "{\n" + "\"id\": 1,\n" + "\"data\":[\n" + "{\n" + "\"to\":123456789,\"name\":\"james\",\"value\":200\n" + "},\n" + "{\n" + "\"to\":123456789,\"name\":\"jhon\",\"value\":20\n" + "}]\n" + "}\n" + "";
    Pattern pattern = Pattern.compile("(?:\"name\":\")(.*?)(?:\"value\":)[0-9]*");
    Matcher m = pattern.matcher(inputString);

    while (m.find()) {
        String[] matches = m.group().split(",");
        String name = null, value = null;
        for (String match : matches) {
            if(match.contains("name")){
                name= match.substring(match.indexOf("name")+"name".length()).replaceAll("\"", "");
            }else if(match.contains("value")) {
                value= match.substring(match.indexOf("value")+"value".length()).replaceAll("\"", "");
            }
        }
        System.out.println("Bonjour Mr. "+name+" votre score est value "+value);
    }       
}

edited Oct 16 '18 at 15:56

answered Oct 16 '18 at 12:55

Amit Kumar Lal

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That's a good answer, but when the json is written differently your regex won't work, here you supposed that always name and value come like in the example, you may have name,sthElse, value ... – Mustapha Belmokhtar Oct 16 '18 at 13:07
@мυѕτавєւмo I have updated my answer with the requirements that you have mentioned, this works when even there is some key-value pair JSON data in-between name and value – Amit Kumar Lal Oct 16 '18 at 15:57
@the hosss will you please look at the answer provided and see if it serve your purpose – Amit Kumar Lal Oct 17 '18 at 06:35

score 0 · Answer 2 · answered Oct 16 '18 at 12:57

I kind of understand the aim of your code, here is an attempt to get for each entry in the json array, the name and the values of each, I hope it helps.

String json = "{\n" + "\"id\": 1,\n" + "\"data\":[\n" + "{\n"
            + "\"to\":123456789,\"name\":\"james\",\"value\":200\n" + "},\n" + "{\n"
            + "\"to\":123456789,\"name\":\"jhon\",\"value\":20\n" + "}]\n" + "}\n" + "";

    JSONObject jsonObject = new JSONObject(json);
    JSONArray arrayOfdata = (JSONArray) jsonObject.get("data");

    String message = "hello Mr %s your score is %s";

    for (int i = 0; i < arrayOfdata.length(); i++) {
        JSONObject obj = arrayOfdata.getJSONObject(i);
        Object name = obj.get("name");
        Object value = obj.get("value");

        System.out.printf(message, name, value);
        System.out.println();
    }

replace substring from string in java

2 Answers2