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.
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.
I'm trying to send a POST param to a REST endpoint I have. This param is a JSON String, that contains special chars like double quotes ("). On the endpoint I keep on getting the String encoded.
THis is the request part:
HttpClient client = HttpClientBuilder.create().build();
StringBuilder query = new StringBuilder();
query.append(callBackURL);
ArrayList<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("update", "{\"object\":\"page\",\"entry\":[{\"id\":\"316492991876763\",\"time\":1417436403,\"changes\":[{\"field\":\"feed\",\"value\":{\"item\":\"comment\",\"verb\":\"add\",\"comment_id\":\"321528008039928_323256911200371\",\"parent_id\":\"316492991876763_321528008039928\",\"sender_id\":100006737955082,\"created_time\":1417436403}}]}]}"));
try {
HttpPost post = new HttpPost(query.toString());
post.setEntity(new UrlEncodedFormEntity(urlParameters));
post.addHeader("content-type", "application/json");
HttpResponse response = null;
try {
response = client.execute(post);
}
catch (IOException e) {
System.out.println(e.getMessage());
}
}
catch (UnsupportedEncodingException e2) {
System.out.println(e2.getMessage());
}
Now in the endpoint part:
/**
* Callback method that receives FB updates
* #return 200 OK if everything goes OK, 401 ERROR otherwise
*/
#POST
#Path("/callback")
#Consumes(MediaType.APPLICATION_JSON)
public Response facebookUpdate(String update, #Context HttpServletRequest request, #Context HttpServletResponse response) throws ServletException, IOException{
JsonParser jsonParser = new JsonParser();
//parse it
JsonElement json = jsonParser.parse(update);
...
}
What I'm getting is a String encoded like this:
%7B%22object%22%3A%22page%22%2C%22entry%22%3A%5B%7B%22id%22%3A%22316492991876763%22%2C%22time%22%3A1417436403%2C%22changes%22%3A%5B%7B%22field%22%3A%22feed%22%2C%22value%22%3A%7B%22item%22%3A%22comment%22%2C%22verb%22%3A%22add%22%2C%22comment_id%22%3A%22321528008039928_323256911200371%22%2C%22parent_id%22%3A%22316492991876763_321528008039928%22%2C%22sender_id%22%3A100006737955082%2C%22created_time%22%3A1417436403%7D%7D%5D%7D%5D%7D
Something I cannot convert to a JsonElement...
Any ideas how to avoid this?
Thanks!
Alejandro
UPDATE:
I found what the problem was, so I'm explaining it here in case anyone has the same problem.
I was trying to pass a param using a BasicNameValuePair, like so:
ArrayList<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("update", "{\"object\":\"page\",\"entry\":[{\"id\":\"316492991876763\",\"time\":1417436403,\"changes\":[{\"field\":\"feed\",\"value\":{\"item\":\"comment\",\"verb\":\"add\",\"comment_id\":\"321528008039928_323256911200371\",\"parent_id\":\"316492991876763_321528008039928\",\"sender_id\":100006737955082,\"created_time\":1417436403}}]}]}"));
I've changed to a simple StringEntity, like this:
StringEntity params = new StringEntity(json.toString());
HttpPost post = new HttpPost(query.toString());
Thus, I don't need to decode. Mistery remains on why passing an Array of BasicNameValuePair will encode the String...
use annotation above the method you want to produce JSON from
#Produces("application/json")
Hi iam creating an android application. In my application i have some form fields like edittext and radio buttons i am creating a JSONObject by retrieving text from all the form fields. JsonObject is created successfully. Now i want to pass this object to my PHP page where i have written code for getting this details and storing it in database. My problem is i am not understanding how to send this JSON object through httpPost or httpGet method. Only way i know is send parameters through List<NameValuePair> so i'm trying to convert JSONObject to List<NameValuePair>. Can anybody provide a method which can directly convert my JSONObject to List<NameValuePair>. Is there any predefined method for doing this. Or can any one provide solution where i can directly send by JSONObject to PHP and retrieve there.
Pass your JSONObject as a string to the String Entity constructor and then pass it to setEntity()
Sample:
HttpPost request = new HttpPost("//website");
StringEntity params =new StringEntity("passmyjson=" + yourJSONOBject.toString());
request.addHeader("content-type", "//header");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
in php File to check that it works;
<?php
print_r($_POST);
$json_string = $_POST['passmyjson'];
$json = json_decode($json_string);
print_r($json);
?>
You can do that with Apache HttpClient. I assume you have already a PHP handler that handles this request. Simply,
Create your JSONObject
Put your desired values
Send that json to php handler
You need to send request as application/x-www-form-urlencoded
Let's call url : http://your_php_service.com/handleJson;
HttpClient httpClient = new DefaultHttpClient();
JSONObject json = new JSONObject();
json.put("key", "val");
try {
HttpPost request = new HttpPost("http://your_php_service.com/handleJson");
StringEntity params = new StringEntity("json=" + json.toString());
request.addHeader("content-type", "application/x-www-form-urlencoded");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
} catch (Exception ex) {
} finally {
httpClient.getConnectionManager().shutdown();
}
The format of request param will be ;
json={"key": "val"}
And you can handle this on php side like;
<?php
.....
$json = $_POST["json"]; // This will be json string
.....
Thank you all i got it
I added the following lines to my android Activity class
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse httpResponse;
HttpPost httppost = new HttpPost(link); //-->link is the php page url
httppost.setEntity(new StringEntity(obj.toString())); //-->obj is JSONObject
httpResponse = httpClient.execute(httppost);
HttpEntity httpEntity = httpResponse.getEntity();
and in my php file i have added the following code
$msg=json_decode(file_get_contents('php://input'), true);
To get particular value from recieved Json string i added this $data = $msg['name'] ;
It is working
I am trying to make a request to a webApi url, u have written the following code and i have my parameters in a NameValuePair object.
Now i don't know how to add these parameters to the base uri do i have to do it manually by concatenating strings? or is there any other way, please help.
private static final String apiBaseUri="http://myapp.myweb.com/path?";
private boolean POST(List<NameValuePair>[] nameValuePairs){
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(apiBaseUri);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs[0]));
HttpResponse response = httpclient.execute(httppost);
String respond = response.getStatusLine().getReasonPhrase();
Log.d("MSG 3 > ",respond);
return true;
}
you can use this to add the parameters to the url
nameValuePairs.add(new BasicNameValuePair("name",value));
String UrlString = URLEncodedUtils.format(nameValuePairs, "utf-8");
url +=UrlString;