How do I pretty-print existing JSON data with Java?
JavaJsonFormattingPretty PrintJava Problem Overview
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.
Java Solutions
Solution 1 - Java
int spacesToIndentEachLevel = 2;
new JSONObject(jsonString).toString(spacesToIndentEachLevel);
Using org.json.JSONObject
(built in to JavaEE and Android)
Solution 2 - Java
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 - Java
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 - Java
In one line:
String niceFormattedJson = JsonWriter.formatJson(jsonString)
or
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.
Solution 5 - Java
If you are using jackson you can easily achieve this with configuring a SerializationFeature
in your ObjectMapper
:
com.fasterxml.jackson.databind.ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationFeature.INDENT_OUTPUT, true);
mapper.writeValueAsString(<yourObject>);
Thats it.
Solution 6 - Java
I think for pretty-printing something, it's very helpful to know its structure.
To get the structure you have to parse it. Because of this, I don't think it gets much easier than first parsing the JSON string you have and then using the pretty-printing method toString mentioned in the comments above.
Of course you can do similar with any JSON library you like.
Solution 7 - Java
I fount a very simple solution:
<dependency>
<groupId>com.cedarsoftware</groupId>
<artifactId>json-io</artifactId>
<version>4.5.0</version>
</dependency>
Java code:
import com.cedarsoftware.util.io.JsonWriter;
//...
String jsonString = "json_string_plain_text";
System.out.println(JsonWriter.formatJson(jsonString));
Solution 8 - Java
Underscore-java library has methods U.formatJson(json)
and U.formatXml(xml)
.