Java escape JSON String?

Question

I have the following JSON string that i am sending to a NodeJS server:

String string = \"{\\\"id\\\":\\\"\" + userID + \"\\\",\\\"type\\\":\\\"\" + methoden          


        

Answer 1

Consider Moshi's JsonWriter class (source). It has a wonderful API and it reduces copying to a minimum, everything is nicely streamed to the OutputStream.

OutputStream os = ...;
JsonWriter json = new JsonWriter(Okio.sink(os));
json
  .beginObject()
  .name("id").value(userID)
  .name("type").value(methodn)
  ...
  .endObject();

Answer 2

If you want to simply escape a string, not an object or array, use this:

String escaped = JSONObject.valueToString(" Quotes \" ' ' \" ");

http://www.json.org/javadoc/org/json/JSONObject.html#valueToString(java.lang.Object)

Answer 3

I would use a library to create your JSON String for you. Some options are:

• GSON
• Crockford's lib

This will make dealing with escaping much easier. An example (using org.json) would be:

JSONObject obj = new JSONObject();

obj.put("id", userID);
obj.put("type", methoden);
obj.put("msg", msget);

// etc.

final String json = obj.toString(); // <-- JSON string

Answer 4

According to the answer here, quotes in values need to be escaped. You can do that with \"

So just repalce the quote in your values

msget = msget.replace("\"", "\\\"");

Answer 5

The best method would be using some JSON library, e.g. Jackson ( http://jackson.codehaus.org ).

But if this is not an option simply escape msget before adding it to your string:

The wrong way to do this is

String msgetEscaped = msget.replaceAll("\"", "\\\"");

Either use (as recommended in the comments)

String msgetEscaped = msget.replace("\"", "\\\"");

or

String msgetEscaped = msget.replaceAll("\"", "\\\\\"");

A sample with all three variants can be found here: http://ideone.com/Nt1XzO

Answer 6

Try to replace all the " and ' with a \ before them. Do this just for the msget object(String, I guess). Don't forget that \ must be escaped too.