如何将包含字符串列表的JsonNode转换为Java中的逗号分隔字符串

Question

JsonNode:

{
  name: ["bishal", "jaiswal", "Turtle"],
  title: "jaiswal"
}

I want to extract the list of name from jsonNode as a comma separated string in an efficient way:

Output:

nameList ="bishal,jaiswal,Turtle"

Apart from converting the jsonNode of name array to a list & then using the join method to make the comma separated string. Any better way to do this ?

Answer 1

Here is the hack

    ObjectMapper objectMapper = new ObjectMapper();
    final JsonNode jsonNode = objectMapper.readTree("{\"name\":[\"bishal\",\"jaiswal\",\"Turtle\"],\"title\":\"jaiswal\"}");
    final JsonNode name = jsonNode.get("name");
    final Iterator<JsonNode> iterator = name.iterator();
    StringBuilder s = new StringBuilder();
    while (iterator.hasNext()){
        final JsonNode next = iterator.next();
        if(s.length() > 0){
            s.append(",");
        }
        s.append(next);
    }
    System.out.println(s.toString());

Hope so it will help you.

Answer 2

You can use Jackson JSON in this case...

Jackson is a very popular and efficient java based library to serialize or map Java objects to JSON and vice versa

For eg

ObjectMapper objectMapper = new ObjectMapper();
JsonNode rootNode = objectMapper.readTree(jsonData); //jsonData is your json string here...
JsonNode names = rootNode.path("name");

Iterator<JsonNode> elements = names.elements();

while(elements.hasNext()){
    JsonNode name = elements.next();
    System.out.println("Names are = "+name);
}

Please can you let me know if this has solved your problem? Thanks