GSON not sending in UTF-8

问题:

The following method sends a JSON reply. However on the receiving end I keep getting invalid characters, and UTF-8 isn't decoding the data. What am I doing wrong?

Response to client = data output stream

//Get the client request
            clientRequest = new BufferedReader(new InputStreamReader(connectedClient.getInputStream())); //connectedclient = socket

            //Start response object
            responseToClient = new DataOutputStream(connectedClient.getOutputStream());


/**
     * Sends a JSON response for an object
     * @param objectToEncode
     * @throws Exception
     */
    private void sendJSONResponse(Object objectToEncode) throws Exception{

        //Encode object into JSON
        String jsonString = new Gson().toJson(objectToEncode);

        // HTTP Header... Status code, last modified
        responseToClient.writeBytes(HTTP_OK_STATUS_CODE);
        responseToClient.writeBytes(CONTENT_TYPE_JSON);
        responseToClient.writeBytes("Last-modified: "+ HelperMethods.now() +" \r\n");
        responseToClient.writeBytes("\r\n"); 

        // The HTTP content starts here
        responseToClient.writeBytes(jsonString);

    }

回答1:

I have no idea why you would write your own HTTP protocol code. It's a lot like writing your own XML parser: No matter how good a programmer you are, you are bound to get it wrong.

Anyway, as the DataOutputStream documentation states, doing writeBytes on a String will just discard its high eight bits. So what you get is... something, but not UTF8. What you should do is:

String jsonString = new Gson().toJson(objectToEncode);
byte[] utf8JsonString = jsonString.getBytes("UTF8");
responseToClient.write(utf8JsonString, 0, utf8JsonString.Length);

回答2:

The first solution didn't work for me, I did this:

Gson gson = new GsonBuilder().disableHtmlEscaping().create();
String json = gson.toJson(objectToEncode);

回答3:

Use the following code to encode

 response.setCharacterEncoding("UTF8"); // this line solves the problem
 response.setContentType("application/json");