java - Issues with using Gson to pretty-print JSON String

Question

Could someone please suggest why this is happening...

I’ve got some code to pretty print some JSON. To do this, I am making use out of the Gson library.

However, while thus usually works well, some characters don’t seem to be displayed properly. Here is a simple piece of code that demonstrates the problem:

//Creating the JSON object, and getting as String:
JsonObject json = new JsonObject();
JsonObject inner = new JsonObject();
inner.addProperty("value", "xpath('hello')");
json.add("root", inner);
System.out.println(json.toString());

//Trying to pretify JSON String:
Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonParser parser = new JsonParser();
JsonElement je = parser.parse(json.toString());
System.out.println(gson.toJson(je));

The output of the above code is:

{"root":{"value":"xpath('hello')"}}
{
  "root": {
    "value": "xpath(u0027hellou0027)"
  }
}

How could I fix the above?

Answer 1

Use this code, to create Gson object:

Gson gs = new GsonBuilder()
    .setPrettyPrinting()
    .disableHtmlEscaping()
    .create();

The disableHtmlEscaping() method tells gson not to escape HTML characters such as <, >, &, =, and a single quote which caused you trouble: '.

Note, that this may cause trouble, if you render such unescaped JSON into a <script/> tag in HTML page without using additional <![CDATA[ ... ]]> tag.

You can see how it works, and what other chars are escaped, by looking into the code of JsonWriter class.