How do I pretty-print existing JSON data with Java? [closed]

I have a compact JSON string, and I want to format it nicely in Java without having to deserialize it first -- e.g. just like jsonlint.org does it. Are there any libraries out there that provides this?

A similar solution for XML would also be nice.

Solution 1:

int spacesToIndentEachLevel = 2;
new JSONObject(jsonString).toString(spacesToIndentEachLevel);

Using org.json.JSONObject (built in to JavaEE and Android)

Solution 2:

Use gson. https://www.mkyong.com/java/how-to-enable-pretty-print-json-output-gson/

Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(my_bean);

output

{
  "name": "mkyong",
  "age": 35,
  "position": "Founder",
  "salary": 10000,
  "skills": [
    "java",
    "python",
    "shell"
  ]
}

Solution 3:

Another way to use gson:

String json_String_to_print = ...
Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonParser jp = new JsonParser();
return gson.toJson(jp.parse(json_String_to_print));

It can be used when you don't have the bean as in susemi99's post.

Solution 4:

In one line:

String niceFormattedJson = JsonWriter.formatJson(jsonString)

System.out.println(JsonWriter.formatJson(jsonString.toString()));

The json-io libray (https://github.com/jdereg/json-io) is a small (75K) library with no other dependencies than the JDK.

In addition to pretty-printing JSON, you can serialize Java objects (entire Java object graphs with cycles) to JSON, as well as read them in.