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Send HTTPS request with JSON through Java [duplicate]

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.

Here is what you need to do:
Get the Apache HttpClient, this would enable you to make the required request
Create an HttpPost request with it and add the header application/x-www-form-urlencoded
Create a StringEntity that you will pass JSON to it
Execute the call
The code roughly looks like (you will still need to debug it and make it work):
// #Deprecated HttpClient httpClient = new DefaultHttpClient();
HttpClient httpClient = HttpClientBuilder.create().build();
try {
HttpPost request = new HttpPost("http://yoururl");
StringEntity params = new StringEntity("details={\"name\":\"xyz\",\"age\":\"20\"} ");
request.addHeader("content-type", "application/x-www-form-urlencoded");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
} catch (Exception ex) {
} finally {
// #Deprecated httpClient.getConnectionManager().shutdown();
}

You can make use of Gson library to convert your java classes to JSON objects.
Create a pojo class for variables you want to send
as per above Example
{"name":"myname","age":"20"}
becomes
class pojo1
{
String name;
String age;
//generate setter and getters
}
once you set the variables in pojo1 class you can send that using the following code
String postUrl = "www.site.com";// put in your url
Gson gson = new Gson();
HttpClient httpClient = HttpClientBuilder.create().build();
HttpPost post = new HttpPost(postUrl);
StringEntity postingString = new StringEntity(gson.toJson(pojo1));//gson.tojson() converts your pojo to json
post.setEntity(postingString);
post.setHeader("Content-type", "application/json");
HttpResponse response = httpClient.execute(post);
and these are the imports
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
and for GSON
import com.google.gson.Gson;

#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();
}

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.

protected void sendJson(final String play, final String prop) {
Thread t = new Thread() {
public void run() {
Looper.prepare(); //For Preparing Message Pool for the childThread
HttpClient client = new DefaultHttpClient();
HttpConnectionParams.setConnectionTimeout(client.getParams(), 1000); //Timeout Limit
HttpResponse response;
JSONObject json = new JSONObject();
try {
HttpPost post = new HttpPost("http://192.168.0.44:80");
json.put("play", play);
json.put("Properties", prop);
StringEntity se = new StringEntity(json.toString());
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
response = client.execute(post);
/*Checking response */
if (response != null) {
InputStream in = response.getEntity().getContent(); //Get the data in the entity
}
} catch (Exception e) {
e.printStackTrace();
showMessage("Error", "Cannot Estabilish Connection");
}
Looper.loop(); //Loop in the message queue
}
};
t.start();
}

Try this code:
HttpClient httpClient = new DefaultHttpClient();
try {
HttpPost request = new HttpPost("http://yoururl");
StringEntity params =new StringEntity("details={\"name\":\"myname\",\"age\":\"20\"} ");
request.addHeader("content-type", "application/json");
request.addHeader("Accept","application/json");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
// handle response here...
}catch (Exception ex) {
// handle exception here
} finally {
httpClient.getConnectionManager().shutdown();
}

I found this question looking for solution about how to send post request from java client to Google Endpoints. Above answers, very likely correct, but not work in case of Google Endpoints.
Solution for Google Endpoints.
Request body must contains only JSON string, not name=value pair.
Content type header must be set to "application/json".
post("http://localhost:8888/_ah/api/langapi/v1/createLanguage",
"{\"language\":\"russian\", \"description\":\"dsfsdfsdfsdfsd\"}");
public static void post(String url, String json ) throws Exception{
String charset = "UTF-8";
URLConnection connection = new URL(url).openConnection();
connection.setDoOutput(true); // Triggers POST.
connection.setRequestProperty("Accept-Charset", charset);
connection.setRequestProperty("Content-Type", "application/json;charset=" + charset);
try (OutputStream output = connection.getOutputStream()) {
output.write(json.getBytes(charset));
}
InputStream response = connection.getInputStream();
}
It sure can be done using HttpClient as well.

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));

For Java 11 you can use the new HTTP client:
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://localhost/api"))
.header("Content-Type", "application/json")
.POST(ofInputStream(() -> getClass().getResourceAsStream(
"/some-data.json")))
.build();
client.sendAsync(request, BodyHandlers.ofString())
.thenApply(HttpResponse::body)
.thenAccept(System.out::println)
.join();
You can use publishers from InputStream, String, File. Converting JSON to a String or IS can be done with Jackson.

Java 11 standardization of HTTP client API that implements HTTP/2 and Web Socket, and can be found at java.net.HTTP.*:
String payload = "{\"name\": \"myname\", \"age\": \"20\"}";
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder(URI.create("www.site.com"))
.header("content-type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(payload))
.build();
HttpResponse<String> response = client.send(request, BodyHandlers.ofString());

Java 8 with apache httpClient 4
CloseableHttpClient client = HttpClientBuilder.create().build();
HttpPost httpPost = new HttpPost("www.site.com");
String json = "details={\"name\":\"myname\",\"age\":\"20\"} ";
try {
StringEntity entity = new StringEntity(json);
httpPost.setEntity(entity);
// set your POST request headers to accept json contents
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");
try {
// your closeablehttp response
CloseableHttpResponse response = client.execute(httpPost);
// print your status code from the response
System.out.println(response.getStatusLine().getStatusCode());
// take the response body as a json formatted string
String responseJSON = EntityUtils.toString(response.getEntity());
// convert/parse the json formatted string to a json object
JSONObject jobj = new JSONObject(responseJSON);
//print your response body that formatted into json
System.out.println(jobj);
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}

I recomend http-request built on apache http api.
HttpRequest<String> httpRequest = HttpRequestBuilder.createPost(yourUri, String.class)
.responseDeserializer(ResponseDeserializer.ignorableDeserializer()).build();
public void send(){
ResponseHandler<String> responseHandler = httpRequest.execute("details", yourJsonData);
int statusCode = responseHandler.getStatusCode();
String responseContent = responseHandler.orElse(null); // returns Content from response. If content isn't present returns null.
}
If you want send JSON as request body you can:
ResponseHandler<String> responseHandler = httpRequest.executeWithBody(yourJsonData);
I higly recomend read documentation before use.

How can I send JSON data to Logstash

I know there is a Logstash http input plugin.
I am wondering if it is possible to send JSON message to Logstash using Java.
I do something like this:
HttpClient httpClient = HttpClientBuilder.create().build();
try {
HttpPost request = new HttpPost("host_name:port/index_name/type_name");
StringEntity params = new StringEntity("{\"message\": {\"fieldName\":\"value\"}}");
request.addHeader("content-type", "application/json");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
} catch (Exception ex) {
}
}
but data is not sent to Logstash.
Could anybody recommend the correct way to do that?

Use Java to get Github repositories

I'm using the following code to send a http request to github.
String url = "https://api.github.com/repositories";
try {
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
HttpPost request = new HttpPost(url);
// StringEntity params = new StringEntity(body);
request.addHeader("content-type", "application/json");
// request.setEntity(params);
HttpResponse result = httpClient.execute(request);
String json = EntityUtils.toString(result.getEntity(), "UTF-8");
System.out.println(json);
} catch (IOException ex) {
}
I got output: {"message":"Not Found","documentation_url":"https://developer.github.com/v3"}
If use directly put "https://api.github.com/repositories" in browser, a lot of useful information will be shown. My question is how can I get the information I see when using browser by using Java.

You should use HttpGet instead of HttpPost. Just like your browser sends a GET request.

Sending and Parsing Response using HTTP Client for a JSON List

With in my java code, I need to send a http post request to a specific URL with 3 headers:
URL: http://localhost/something
Referer: http://localhost/something
Authorization: Basic (with a username and password)
Content-type: application/json
This returns a response with a JSON "key":"value" pair in it that I then need to parse somehow to store the key/value (Alan/72) in a MAP. The response is (when using SOAPUI or Postman Rest):
{
"analyzedNames": [
{
"alternate": false
}
],
"nameResults": [
{
"alternate": false,
"givenName": "John",
"nameCategory": "PERSONAL",
"originalGivenName": "",
"originalSurname": "",
"score": 72,
"scriptType": "NOSCRIPT",
}
]
}
I can do this using SOAPUI or Postman Rest but how can I do this within Java as I'm getting an error:
****DEBUG main org.apache.http.impl.conn.DefaultClientConnection - Receiving response: HTTP/1.1 500 Internal Server Error****
My code is:
public class NameSearch {
/**
* #param args
* #throws IOException
* #throws ClientProtocolException
*/
public static void main(String[] args) throws ClientProtocolException, IOException {
// TODO Auto-generated method stub
DefaultHttpClient defaultHttpClient = new DefaultHttpClient();
StringWriter writer = new StringWriter();
//Define a postRequest request
HttpPost postRequest = new HttpPost("http://127.0.0.1:1400/dispatcher/api/rest/search");
//Set the content-type header
postRequest.addHeader("content-type", "application/json");
postRequest.addHeader("Authorization", "Basic ZW5zYWRtaW46ZW5zYWRtaW4=");
try {
//Set the request post body
StringEntity userEntity = new StringEntity(writer.getBuffer().toString());
postRequest.setEntity(userEntity);
//Send the request; return the response in HttpResponse object if any
HttpResponse response = defaultHttpClient.execute(postRequest);
//verify if any error code first
int statusCode = response.getStatusLine().getStatusCode();
}
finally
{
//Important: Close the connect
defaultHttpClient.getConnectionManager().shutdown();
}
}
}
Any help (with some sample code including which libraries to import) will be most appreciated.
THANKS

Yes, you can do it with java
You need apache HTTP client library http://hc.apache.org/ and commons-io
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost("http://localhost/something");
post.setHeader("Referer", "http://localhost/something");
post.setHeader("Authorization", "Basic (with a username and password)");
post.setHeader("Content-type", "application/json");
// if you need any parameters
List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("paramName", "paramValue"));
post.setEntity(new UrlEncodedFormEntity(urlParameters));
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();
Header encodingHeader = entity.getContentEncoding();
// you need to know the encoding to parse correctly
Charset encoding = encodingHeader == null ? StandardCharsets.UTF_8 :
Charsets.toCharset(encodingHeader.getValue());
// use org.apache.http.util.EntityUtils to read json as string
String json = EntityUtils.toString(entity, StandardCharsets.UTF_8);
JSONObject o = new JSONObject(json);

I recommend http-request built on Apache HTTP API.
HttpRequest<String> httpRequest = HttpRequestBuilder.createPost(yourUri
new TypeReference<Map<String, List<Map<String, Object>>>>{})
.basicAuth(userName, password)
.addContentType(ContentType.APPLICATION_JSON)
.build();
public void send(){
ResponseHandler<String> responseHandler = httpRequest.executeWithBody(yourJsonData);
int statusCode = responseHandler.getStatusCode();
Map<String, List<Map<String, Object>>> response = responseHandler.get(); // Before calling the get () method, make sure the response is present: responseHandler.hasContent()
System.out.println(response.get("nameResults").get(0).get("givenName")); //John
}
I highly recommend reading the documentation before use.
Note: You can create your custom type instead of Map to parse response. See my answer here.

Android http post advanced request with body on hostmachine

I would like to do a HTTP post request from my virtual android device on the hostmachine.
Below you'll see an image on how I post, by using the old WebFetch tool.
I don't know what URL to use for calling the hostmachine?
I got no idea how my body string can be used an input?
Does anybody have an idea on how to solve this?

If you want to connect to the computer which is running the Android simulator, use the IP address 10.0.2.2. You can read more about it here.
Also check out the accepted answer in following question to see how json can be send as post data:
How to send POST request in JSON using HTTPClient?
you can use following code to make HTTP get request:
try {
HttpClient client = new DefaultHttpClient();
String getURL = "http://10.0.2.2:port/your_path_with_parameter";
HttpGet get = new HttpGet(getURL);
HttpResponse responseGet = client.execute(get);
HttpEntity resEntityGet = responseGet.getEntity();
if (resEntityGet != null) {
//do something with the response
Log.i("GET RESPONSE",EntityUtils.toString(resEntityGet));
}
} catch (Exception e) {
e.printStackTrace();
}