CODEWITHSUNDEEP
javajsonhttppost
jkally
jkally

Reputation: 814

How to write a very basic POST client in Java

I have to write the most basic POST client in Java. It sends a few parameters to a Certificate server. The parameters are supposed to be JSON encoded

I have the attached code, how do I make the params JSON encoded?

   String url = "http://x.x.x.x/CertService/revoke.php";

    URL obj = new URL(url);
    HttpURLConnection con = (HttpURLConnection) obj.openConnection();

    //add reuqest header
    con.setRequestMethod("POST");
    con.setRequestProperty("User-Agent", "Mozilla/5.0");
    con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

    String urlParameters = "serialnumber=C02G8416DRJM&authtoken=abc&caauthority=def&reason=ghi";

    // Send post request
    con.setDoOutput(true);
    DataOutputStream wr = new DataOutputStream(con.getOutputStream());
    wr.writeBytes(urlParameters);
    wr.flush();
    wr.close();

    int responseCode = con.getResponseCode();

Upvotes: 0

Views: 37

Answers (2)

VicX
VicX

Reputation: 711

Can you just set your content type as application/json and send the json string?

con.setRequestProperty("Content-Type", "application/json");

Upvotes: 1

hearnden
hearnden

Reputation: 572

The text you're POSTing in your example looks like it's application/x-www-form-urlencoded. To get application/json encoding, prepare the parameters as a map, then use any of several JSON encoding libraries (e.g., Jackson) to convert it to JSON.

Map<String,String> params = new HashMap<>();
params.put("serialnumber", "C02G8416DRJM");
params.put("authtoken", "abc");
...
ObjectMapper mapper = new ObjectMapper();
OutputStream os = con.getOutputStream();
mapper.writeValue(os, params);
os.flush();
os.close();
...

Upvotes: 0

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