How can I encode JSON object content into a JSON string?

Question

Trying to find a way to stringify a JSON string, with escape characters like JavaScript.

For example --

Input:

{"name":"Error","message":"hello"}

Output:

"{\"name\":\"Error\",\"message\":\"hello\"}"

I am able to get the object as JSON String using Gson, but not stringify (with escape characters).

Is this possible with Java?

https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringEscapeUtils.html#escapeJson-java.lang.String- — Robin Topper, May 16 '17 at 11:42
@RobinTopper That's close to what I am looking for. But Jackson's JsonStringEncoder.quoteAsString() feels like a better alternative for me, as it can correct formatting of JSON as well. — kn_pavan, May 16 '17 at 17:41
Jackson's JsonStringEncoder.quoteAsString() Example: http://stackoverflow.com/a/40430760/639107 — kn_pavan, May 16 '17 at 17:43

Sotirios Delimanolis · Accepted Answer · 2017-09-05T18:06:16.370

Your input is a JSON object as text, presumably stored in a String. You're essentially trying to convert that text to a JSON string. So do just that.

String input = "{\"name\":\"Error\",\"message\":\"hello\"}";
System.out.println("Original JSON content: " + input);
Gson gson = new Gson();
String jsonified = gson.toJson(input);
System.out.println("JSONified: " + jsonified);

Since quotes (and other characters) must be escaped in JSON strings, the toJson will properly perform that transformation.

The code above will produce the

Original JSON content: {"name":"Error","message":"hello"}
JSONified: "{\"name\":\"Error\",\"message\":\"hello\"}"

In other words, jsonified now contains the content of a JSON string.

With Jackson, the process is the same, just serialize the String instance that contains your JSON object text

ObjectMapper mapper = new ObjectMapper();
StringWriter writer = new StringWriter();
mapper.writeValue(writer, input);
jsonified = writer.toString();
System.out.println("JSONified: " + jsonified);

produces

JSONified: "{\"name\":\"Error\",\"message\":\"hello\"}"

score 1 · Answer 2 · answered Apr 09 '18 at 06:36

1

Another solution, I noted in comments:

Jackson's JsonStringEncoder.quoteAsString() Example: stackoverflow.com/a/40430760/639107

answered Apr 09 '18 at 06:36

kn_pavan

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score 0 · Answer 3 · answered May 16 '17 at 11:47

0

You can try this on your output json string :

String strWithEscChar = output.replaceAll("\"", "\\\\\"");

answered May 16 '17 at 11:47

Yan.F

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How can I encode JSON object content into a JSON string?

3 Answers3