Notation of JSON in Java for test

A few helper static methods provide pretty good readability in Java for JSON literal.

String json = _j(
    "'name':'Jhon'",
    "'age':23",
    "'pet':" + _j(
        "'name':'Coggy'",
        "'age':3"
    ),
    "'interests':"  + _a(1, 2, "'a'", "'b'", 3)
);
System.out.println(json);
public static String _(String left, String right, Object... props) {
    return left + join(props, ", ").replaceAll("'", "\"") + right;
}
public static String _j(Object... props) {
    return _("{", "}", props);
}
public static String _a(Object... props) {
    return _("[", "]", props);
}

It's a bit problem that cannot contain "'" in each value though I don't think severe issue.

Here is output (actually no indentation)

{
  "name":"Jhon",
  "age":23,
  "pet":{
    "name":"Coggy",
    "age":3
  },
  "interests":[1, 2, "a", "b", 3]
}