HTTP POST using JSON in Java

Question

I would like to make a simple HTTP POST using JSON in Java.

Let's say the URL is www.site.com

and it takes in the value {"name":"myname","age":"20"} labeled as 'details' for example.

How would I go about creating the syntax for the POST?

I also can't seem to find a POST method in the JSON Javadocs.

Answer 1

@momo's answer for Apache HttpClient, version 4.3.1 or later. I'm using JSON-Java to build my JSON object:

JSONObject json = new JSONObject();
json.put("someKey", "someValue");    

CloseableHttpClient httpClient = HttpClientBuilder.create().build();

try {
    HttpPost request = new HttpPost("http://yoururl");
    StringEntity params = new StringEntity(json.toString());
    request.addHeader("content-type", "application/json");
    request.setEntity(params);
    httpClient.execute(request);
// handle response here...
} catch (Exception ex) {
    // handle exception here
} finally {
    httpClient.close();
}

Answer 2

It's probably easiest to use HttpURLConnection.

http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139

You'll use JSONObject or whatever to construct your JSON, but not to handle the network; you need to serialize it and then pass it to an HttpURLConnection to POST.

Answer 3

You can use the following code with Apache HTTP:

String payload = "{\"name\": \"myname\", \"age\": \"20\"}";
post.setEntity(new StringEntity(payload, ContentType.APPLICATION_JSON));

response = client.execute(request);

Additionally you can create a json object and put in fields into the object like this

HttpPost post = new HttpPost(URL);
JSONObject payload = new JSONObject();
payload.put("name", "myName");
payload.put("age", "20");
post.setEntity(new StringEntity(payload.toString(), ContentType.APPLICATION_JSON));