How to Structure JSON response properly in Java

Question

When sending my JSON response I get in visible form the content-type. This is an issue because when I parse the JSON on the other side it includes the headers and it can't parse back into a hashmap.

How should I encode this response so that the headers don't "show"

Here is the method that generates the response

/**
     * Sends reply back to client
     * @throws Exception
     */
    private void sendResponse() throws Exception{

        //Content type
        String contentTypeLine = "Content-Type: text/json" + "\r\n";

        //Create dummy JSON object
        HashMap<String, String> mapResponse = new HashMap<String, String>();
        mapResponse.put("Author", "James");
        mapResponse.put("Author 2", "John");

        //Convert to JSON
        Gson gson = new Gson();
        String json = gson.toJson(mapResponse);

        //Set type
        responseToClient.writeBytes(contentTypeLine);

        //Set JSON
        responseToClient.writeBytes(json);

    }

Here is the sample response

Content-Type: text/json
{"Author":"James","Author 2":"John"}

Request getting code

/**
     * Code to execute on thread
     */
    public void run(){

        try {

            //Log new client
            System.out.println("The client " + connectedClient.getInetAddress() + 
                    ":" + connectedClient.getPort() + " is connected");

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

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

            //Process the request
            processClientRequest();

            //Close buffered writer
            responseToClient.close();
        } catch (Exception e) {

            //Print error
            e.printStackTrace();
        }
    }

Thank you!

You could just go line by line and do a simple if(line.contains("{")) then // do something — shaunw, Jun 06 '13 at 20:56

score 3 · Accepted Answer · answered Jun 06 '13 at 20:57

3

You don't need to have this line:

responseToClient.writeBytes(contentTypeLine);

You just need to call HttpServletResponse#setHeader("Content-type, "application/json") to set appropriate content-type.

answered Jun 06 '13 at 20:57

anubhava

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2

Yeah, I believe you meant response.setHeader("Content-Type"). – asgs Jun 06 '13 at 20:58
responseToClient is a DataOutputStream – William Falcon Jun 06 '13 at 20:59
@waf: I understand that responseToClient is an OutputStream but you don't need to write content type into the OutputStream. May be just set the headers as I suggested. – anubhava Jun 06 '13 at 21:02
I get it, however I'm not sure where to do that. I updated the code above. I don't have a HttoServletResponse – William Falcon Jun 06 '13 at 21:03
If you have `connectedClient` of type URLConnection then you can call: `connectedClient.setRequestProperty("Content-type, "application/json") ;` – anubhava Jun 06 '13 at 21:08
Hmm looks like you just have Socket type. See this answer for more help: http://stackoverflow.com/questions/10788125/a-simple-http-server-with-java-socket – anubhava Jun 06 '13 at 21:11
That last link was what was missing. Thank you – William Falcon Jun 06 '13 at 21:27
You're welcome, glad that it worked out for you. And don't forget to upvote that Q&A as well :P – anubhava Jun 06 '13 at 21:29

How to Structure JSON response properly in Java

1 Answers1