Error trying to post JSON data to Android Device - java

I've followed the tutorial here in an attempt to send data to an android device. I've whittled my Java class down to this:
public class App {
public static void main( String[] args ) {
try {
String apiKey = "api key generated in Google Developer Console...";
String deviceId = "Device Id generated, retrieved directly from logcat, as per tutorial...";
Content content = new Content();
content.addRegId(deviceId);
content.createData("Title", "Notification Message");
URL url = new URL("https://android.googleapis.com/gcm/send");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Authorization", "key=" + apiKey);
conn.setDoOutput(true);
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
mapper.writeValue(wr, content);
wr.flush();
wr.close();
int responseCode = conn.getResponseCode();
System.out.println(responseCode == 200 ? responseCode + ". This is the response we want..." : responseCode + ". This is not the response we want...");
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println(response.toString());
} catch (MalformedURLException mue) {
mue.printStackTrace();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
and this is my Content class:
public class Content implements Serializable{
private List<String> registration_ids;
private Map<String,String> data;
public void addRegId(String regId) {
if(registration_ids == null)
registration_ids = new LinkedList<String>();
registration_ids.add(regId);
}
public void createData(String title, String message) {
if (data == null)
data = new HashMap<String,String>();
data.put("title", title);
data.put("message", message);
}
}
I'm getting a 400 response code
java.io.IOException: Server returned HTTP response code: 400 for URL: https://android.googleapis.com/gcm/send
I'm sure I'm missing something small, but I can't see where it is.

Related

Java HTTPURLConnection - Reading error response from code 400 with payload

I am trying to call an API that gives 400 on some requests.
But it has meaningful message that needs to be read.
Also i am passing a payload(json body) in the api call
My code(it takes a payload as json) and the 400 response is below
I am able to successfully read the response of 200 but issue is with 400
public static void blahblah (String input, String CustomerID, String endpoint, String dateNameFolder) throws UnknownHostException
{
try {
URL url = new URL(endpoint);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
OutputStream os = conn.getOutputStream();
os.write(input.getBytes());
os.flush();
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
StringBuilder sb = new StringBuilder();
String output;
while ((output = br.readLine()) != null) {
sb.append(output);
}
File fileObj = new File(CustomerID + ".json");
if (!fileObj.exists()) {
fileObj.createNewFile();
FileWriter dataWriter = new FileWriter(CustomerID + ".json");
dataWriter.write(sb.toString());
dataWriter.close();
} else {
FileWriter dataWriter = new FileWriter(CustomerID + ".json");
dataWriter.write(sb.toString());
dataWriter.close();
}
conn.disconnect();
}catch (MalformedURLException e) {
l
log.info(e);
}
catch (IOException e) {
log.error("Error in Validating Request to Catalog for Customer ID(400 Bad Request) : " + CustomerID ) ;
log.info(e);
}
}
Sample output of 400 bad request :
<Response>
<StatusCode>BadRequest</StatusCode>
<ErrorCode>OrderRequestInvalid.InvalidCharacteristicUse</ErrorCode>
<Message>Characteristic ID cannot be found in the specification: { EntityUniqueCode: CS_0aefdfec-022e-4ac9-a84b-83c8ea2e0fd0, CharacteristicID: 76c4e767-ce7b-4675-a178-d832839b322f}</Message>
<Context>
<EntityUniqueCode>CS_0aefdfec-022e-4ac9-a84b-83c8ea2e0fd0</EntityUniqueCode>
<CharacteristicID>76c4e767-ce7b-4675-a178-d832839b322f</CharacteristicID>
</Context>
</Response>
You need to choose correct stream depending on your response status. here is an example how you can do this:
BufferedReader br = null;
int statusCode = conn.getResponseCode();
if (statusCode>299){
br = new BufferedReared(new InputStreamReader(conn.getErrorStream()));
} else {
br = new BufferedReared(new InputStreamReader(conn.getInputStream()));
}

java rest call response body missing in case of bad request

I am hitting below url using any rest client and I get the api Response :400 Bad Request with response body
INPUT param
POST http://SOME.IP:8008/equipment_api/F0-03-8C-C3-D3-CC/832
HEADERS
Content-Type application/json
X-RequestID 1234
BODY
{
"items":[{"updateValue":1, "updateKey": "RESETDEV"}],
"sync":"false"
}
Response :400 Bad Request
{
"error": "RESETDEV is not a valid key."
}
But java simple client does not show the response body.. below is java code.. it just give 400 bad req.
public static void main(String[] args) {
try {
String urlParameters = " {\r\n" +
"\"items\":[{\"updateValue\":\"Hi\", \"updateKey\": \"RESETDEV\"}],\r\n" +
"\"sync\":false\r\n" +
"}";
URL url = new URL("http://SOME.IP:8008/equipment_api/F0-03-8C-C3-D3-CC/832");
URLConnection conn = url.openConnection();
conn.setRequestProperty("content-type", "application/json");
conn.setRequestProperty("X-RequestID", "1234");
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
writer.close();
reader.close();
}catch(Exception ex) {
System.out.println("some error :: "+ex.toString());
}
}
Try to use following code
final String uri = "http://SOME.IP:8008/equipment_api/F0-03-8C-C3-D3-CC/832";
RestTemplate restTemplate = new RestTemplate();
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<String>("X-RequestID", "1234");
ResponseEntity<String> result = restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);
System.out.println(result);
Wrap with Try Catch.
May it is useful to you. It will work
public static void main(String[] args) {
try {
String urlParameters = " {\r\n" +
"\"items\":[{\"updateValue\":\"Hi\", \"updateKey\":
\"RESETDEV\"}],\r\n" +
"\"sync\":false\r\n" +
"}";
URL url = new URL("http:http://SOME.IP:8008/equipment_api/F0-03-
8C-C3-D3-CC/832");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestProperty("content-type", "application/json");
con.setRequestProperty("X-RequestID", "1234");
con.setDoOutput(true);
OutputStreamWriter writer = new
OutputStreamWriter(con.getOutputStream());
writer.write(urlParameters);
writer.flush();
String line;
//BufferedReader reader = new BufferedReader(new
InputStreamReader(con.getInputStream()));
InputStream is = con.getInputStream();
if(con.getResponseCode() >= 200 && 299 <= con.getResponseCode()) {
is = con.getInputStream();
}else {
is = con.getErrorStream();
}
try (BufferedReader br = new BufferedReader(new InputStreamReader(is,
"utf-8"))) {
while ((line = br.readLine()) != null) {
System.out.println(line);
}
}
writer.close();
// br.close();
}catch(Exception ex) {
System.out.println("some error :: "+ex.toString());
}
}

Getting response code 400 when trying to get access token from Azure AD

I am implementing azure for my web application and trying to get access token by following there openId connect tutorial
https://learn.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-code
And when i am requesting to get the access token, i am always getting bad request 400
Request to get access token :
POST /{tenant}/oauth2/token HTTP/1.1
Host: https://login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded
grant_type=authorization_code
&client_id=2d4d11a2-f814-46a7-890a-274a72a7309e
&code=AwABAAAAvPM1KaPl.......
&redirect_uri=https%3A%2F%2Flocalhost%2Fmyapp%2F
&resource=https%3A%2F%2Fservice.contoso.com%2F
&client_secret=p#ssw0rd
here is my code :
public static String post( String endpoint,
Map<String, String> params) {//YD
StringBuffer paramString = new StringBuffer("");
//if(!Utilities.checkInternetConnection(context)){
// return XMLHandler.getXMLForErrorCode(context, JSONHandler.ERROR_CODE_INTERNET_CONNECTION);
//}
Iterator<Entry<String, String>> iterator = params.entrySet().iterator();
StringBuffer tempBuffer = new StringBuffer("");
String paramval;
while (iterator.hasNext()) {
Entry<String, String> param = iterator.next();
if (param != null) {
if (paramString.length() > 0) {
paramString.append("&");
}
System.out.println( "post key : " + param.getKey());
String value;
try {
paramval = param.getValue();
if(paramval!=null)
value = URLEncoder.encode(paramval, "UTF-8");
else
value = "";
} catch (UnsupportedEncodingException e) {
value = "";
e.printStackTrace();
}
paramString.append(param.getKey()).append("=")
.append(value);
}
}
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(endpoint);
String data = "";
try {
// Add your data
// httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs))
//httppost.addHeader("Host", host);
httppost.addHeader("Content-Type",
"application/x-www-form-urlencoded");
if (!paramString.equals("")) {
if (tempBuffer.length() > 0) {
data = data + tempBuffer.toString();
}
data = data + paramString.toString();
if (data.endsWith("&")) {
data = data.substring(0, data.length() - 1);
}
httppost.setEntity(new ByteArrayEntity(data.getBytes()));
}
System.out.println( "post Stringbuffer : " + data);
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
int statuscode = response.getStatusLine().getStatusCode();
System.out.println("Response code : " + statuscode);
if (statuscode != 200) {
return null;
}
HttpEntity entity = response.getEntity();
InputStream in = null;
if (entity != null) {
in = entity.getContent();
}
if (in != null) {
StringBuilder builder = new StringBuilder();
String line;
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(in, "UTF-8"));
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} finally {
in.close();
}
String response2 = builder.toString();
System.out.println("response :" + response2);
retrycount = 0;
return response2;
}
}
catch(UnknownHostException e){
e.printStackTrace();
return null;
}
catch (EOFException eof) {
if (retrycount < max_retry) {
eof.printStackTrace();
post( endpoint, params);
retrycount = 1;
}
} catch (Throwable th) {
throw new IOException("Error in posting :" + th.getMessage());
}
retrycount = 0;
return null;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
Please help me with this
Thanks in Advance
Have you ensured the redirect uri passed to /token is the same as the one you passed to /authorize
I believe, it will help if you can test the OAuth auth code flow with your current client id, secret and scope using Postman tool in order to rule out bad configuration.
Please refer to the code below to request AuthorizationCode.
public static void getAuthorizationCode() throws IOException {
String encoding = "UTF-8";
String params = "client_id=" + clientId
+ "&response_type=" + reponseType
+ "&redirect_uri=http%3A%2F%2Flocalhost%2Fmyapp%2F"
+ "&response_mode=query"
+ "&resource=https%3A%2F%2Fgraph.windows.net"
+ "&state=12345";
String path = "https://login.microsoftonline.com/" + tenantId + "/oauth2/authorize";
byte[] data = params.getBytes(encoding);
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
conn.setConnectTimeout(5 * 1000);
OutputStream outStream = conn.getOutputStream();
outStream.write(data);
outStream.flush();
outStream.close();
System.out.println(conn.getResponseCode());
System.out.println(conn.getResponseMessage());
BufferedReader br = null;
if (conn.getResponseCode() != 200) {
br = new BufferedReader(new InputStreamReader((conn.getErrorStream())));
} else {
br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
}
System.out.println("Response body : " + br.readLine());
}
Then you could get access token using the AuthorizationCode you got and get refresh code using the code below.
public static void getToken(String refreshToken) throws IOException {
String encoding = "UTF-8";
String params = "client_id=" + clientId + "&refresh_token=" + refreshToken
+ "&grant_type=refresh_token&resource=https%3A%2F%2Fgraph.windows.net";
String path = "https://login.microsoftonline.com/" + tenantId + "/oauth2/token";
byte[] data = params.getBytes(encoding);
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
conn.setConnectTimeout(5 * 1000);
OutputStream outStream = conn.getOutputStream();
outStream.write(data);
outStream.flush();
outStream.close();
System.out.println(conn.getResponseCode());
System.out.println(conn.getResponseMessage());
BufferedReader br = null;
if (conn.getResponseCode() != 200) {
br = new BufferedReader(new InputStreamReader((conn.getErrorStream())));
} else {
br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
}
System.out.println("Response body : " + br.readLine());
}
Hope it helps you.

Logging in on website programmatically

I have used this tutorial to try to login to a website from the company I am doing my internship at: http://www.mkyong.com/java/how-to-automate-login-a-website-java-example/
However, It is not logging in, since the URL when you're logged in to the site is the same as when you're not logged in. So all that happens is me adding the data to the fields, and then the page refreshes, with nothing happening. Can anyone tell me how I am supposed to continue?
Thanks
(Edit): I only have a redirect link
public class ProfileLogin extends AsyncTask<Void, Void, Void>{
private List<String> cookies;
private HttpsURLConnection conn;
private final String USER_AGENT = "Mozilla/5.0";
private String page;
private String userName;
private String passWord;
private String postParams;
URL obj;
//Setting up out connection
public ProfileLogin(String user, String pass){
CookieManager cManager = new CookieManager();
CookieHandler.setDefault(cManager);
page = null;
try {
obj = new URL(LOGIN_URL);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//Setting the username and password
userName = user;
passWord = pass;
try {
conn = (HttpsURLConnection) obj.openConnection();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//Starting our Asynctask to do all of the networking
execute();
}
public VpnProfile getProfiles(){
VpnProfile profile = new VpnProfile(null);
return profile;
}
public String getPageContent() throws Exception{
//Set Get method
conn.setRequestMethod("GET");
conn.setUseCaches(false);
//The properties of our site, we need to act like a browser
conn.setRequestProperty("User-Agent", USER_AGENT);
conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
conn.setRequestProperty("Accept-Language", "nl-NL,nl;q=0.8,en-US;q=0.6,en;q=0.4");
if(cookies != null){
for(String cookie : this.cookies){
conn.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
}
}
int responseCode = conn.getResponseCode();
System.out.println("\nSending 'GET' request to URL : " + LOGIN_URL);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while((inputLine = in.readLine()) != null){
response.append(inputLine);
}
in.close();
setCookies(conn.getHeaderFields().get("Set-Cookie"));
return response.toString();
}
private String getFormParams(String userName2, String passWord2) throws Exception{
System.out.println("Extract form's data...");
Document doc = Jsoup.parse(page);
//Elements of the login page
Element userNameElement = doc.getElementById("username");
Element passWElement = doc.getElementById("password");
List<String> paramList = new ArrayList<String>();
paramList.add(userNameElement.attr("name") + "=" + URLEncoder.encode(userName2, "UTF-8"));
paramList.add(passWElement.attr("name") + "=" + URLEncoder.encode(passWord2, "UTF-8"));
StringBuilder result = new StringBuilder();
for(String param : paramList){
if(result.length() == 0){
result.append(param);
} else {
result.append("&" + param);
}
}
return result.toString();
}
private void sendPost(String postParams) throws Exception {
conn = (HttpsURLConnection) obj.openConnection();
//Act like a browser
conn.setUseCaches(false);
conn.setRequestMethod("POST");
//This line is deleted, I can't show the url, I set the host here
conn.setRequestProperty("User-Agent", USER_AGENT);
conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
conn.setRequestProperty("Accept-Language", "nl-NL,nl;q=0.8,en-US;q=0.6,en;q=0.4");
if(cookies != null){
for(String cookie : this.cookies){
System.out.println("This is cookies: " + cookie);
conn.addRequestProperty("cookie", cookie.split(";", 1)[0]);
}
}
conn.setRequestProperty("Connection", "keep-alive");
//Deleted line setting referer URL
conn.setRequestProperty("Content-Type", "text/html; charset=UTF-8");
conn.setRequestProperty("Content-Length", Integer.toString(postParams.length()));
conn.setDoOutput(true);
conn.setDoInput(true);
DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
wr.writeBytes(postParams);
wr.flush();
wr.close();
int responseCode = conn.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + LOGIN_URL);
System.out.println("Post parameters : " + postParams);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while((inputLine = in.readLine()) != null){
response.append(inputLine);
}
in.close();
}
#Override
protected Void doInBackground(Void... arg0) {
try {
page = getPageContent();
postParams = getFormParams(userName, passWord);
sendPost(postParams);
page = getPageContent();
Document doc = Jsoup.parse(page);
Element userNameElement = doc.getElementById("username");
if(userNameElement.toString() != null){
System.out.println("Not logged in");
}else{
System.out.println("Logged in!");
}
}catch(Exception e){
e.printStackTrace();
}
return null;
}
private void setCookies(List<String> cookies) {
this.cookies = cookies;
}
}
I kind of found a way around: How to log into Facebook programmatically using Java?
This works really well for me and gives me really clean and short code :)

Java - sending HTTP parameters via POST method easily

I am successfully using this code to send HTTP requests with some parameters via GET method
void sendRequest(String request)
{
// i.e.: request = "http://example.com/index.php?param1=a&param2=b&param3=c";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("GET");
connection.setRequestProperty("Content-Type", "text/plain");
connection.setRequestProperty("charset", "utf-8");
connection.connect();
}
Now I may need to send the parameters (i.e. param1, param2, param3) via POST method because they are very long.
I was thinking to add an extra parameter to that method (i.e. String httpMethod).
How can I change the code above as little as possible to be able to send paramters either via GET or POST?
I was hoping that changing
connection.setRequestMethod("GET");
to
connection.setRequestMethod("POST");
would have done the trick, but the parameters are still sent via GET method.
Has HttpURLConnection got any method that would help?
Is there any helpful Java construct?
Any help would be very much appreciated.
In a GET request, the parameters are sent as part of the URL.
In a POST request, the parameters are sent as a body of the request, after the headers.
To do a POST with HttpURLConnection, you need to write the parameters to the connection after you have opened the connection.
This code should get you started:
String urlParameters = "param1=a&param2=b&param3=c";
byte[] postData = urlParameters.getBytes( StandardCharsets.UTF_8 );
int postDataLength = postData.length;
String request = "http://example.com/index.php";
URL url = new URL( request );
HttpURLConnection conn= (HttpURLConnection) url.openConnection();
conn.setDoOutput( true );
conn.setInstanceFollowRedirects( false );
conn.setRequestMethod( "POST" );
conn.setRequestProperty( "Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty( "charset", "utf-8");
conn.setRequestProperty( "Content-Length", Integer.toString( postDataLength ));
conn.setUseCaches( false );
try( DataOutputStream wr = new DataOutputStream( conn.getOutputStream())) {
wr.write( postData );
}
Here is a simple example that submits a form then dumps the result page to System.out. Change the URL and the POST params as appropriate, of course:
import java.io.*;
import java.net.*;
import java.util.*;
class Test {
public static void main(String[] args) throws Exception {
URL url = new URL("http://example.net/new-message.php");
Map<String,Object> params = new LinkedHashMap<>();
params.put("name", "Freddie the Fish");
params.put("email", "fishie#seamail.example.com");
params.put("reply_to_thread", 10394);
params.put("message", "Shark attacks in Botany Bay have gotten out of control. We need more defensive dolphins to protect the schools here, but Mayor Porpoise is too busy stuffing his snout with lobsters. He's so shellfish.");
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
byte[] postDataBytes = postData.toString().getBytes("UTF-8");
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
conn.setDoOutput(true);
conn.getOutputStream().write(postDataBytes);
Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
for (int c; (c = in.read()) >= 0;)
System.out.print((char)c);
}
}
If you want the result as a String instead of directly printed out do:
StringBuilder sb = new StringBuilder();
for (int c; (c = in.read()) >= 0;)
sb.append((char)c);
String response = sb.toString();
I couldn't get Alan's example to actually do the post, so I ended up with this:
String urlParameters = "param1=a&param2=b&param3=c";
URL url = new URL("http://example.com/index.php");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
writer.close();
reader.close();
I find HttpURLConnection really cumbersome to use. And you have to write a lot of boilerplate, error prone code. I needed a lightweight wrapper for my Android projects and came out with a library which you can use as well: DavidWebb.
The above example could be written like this:
Webb webb = Webb.create();
webb.post("http://example.com/index.php")
.param("param1", "a")
.param("param2", "b")
.param("param3", "c")
.ensureSuccess()
.asVoid();
You can find a list of alternative libraries on the link provided.
import java.net.*;
public class Demo{
public static void main(){
String data = "data=Hello+World!";
URL url = new URL("http://localhost:8084/WebListenerServer/webListener");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoOutput(true);
con.getOutputStream().write(data.getBytes("UTF-8"));
con.getInputStream();
}
}
i have read above answers and have created a utility class to simplify HTTP request. i hope it will help you.
Method Call
// send params with Hash Map
HashMap<String, String> params = new HashMap<String, String>();
params.put("email","me#example.com");
params.put("password","12345");
//server url
String url = "http://www.example.com";
// static class "HttpUtility" with static method "newRequest(url,method,callback)"
HttpUtility.newRequest(url,HttpUtility.METHOD_POST,params, new HttpUtility.Callback() {
#Override
public void OnSuccess(String response) {
// on success
System.out.println("Server OnSuccess response="+response);
}
#Override
public void OnError(int status_code, String message) {
// on error
System.out.println("Server OnError status_code="+status_code+" message="+message);
}
});
Utility Class
import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.Map;
import static java.net.HttpURLConnection.HTTP_OK;
public class HttpUtility {
public static final int METHOD_GET = 0; // METHOD GET
public static final int METHOD_POST = 1; // METHOD POST
// Callback interface
public interface Callback {
// abstract methods
public void OnSuccess(String response);
public void OnError(int status_code, String message);
}
// static method
public static void newRequest(String web_url, int method, HashMap < String, String > params, Callback callback) {
// thread for handling async task
new Thread(new Runnable() {
#Override
public void run() {
try {
String url = web_url;
// write GET params,append with url
if (method == METHOD_GET && params != null) {
for (Map.Entry < String, String > item: params.entrySet()) {
String key = URLEncoder.encode(item.getKey(), "UTF-8");
String value = URLEncoder.encode(item.getValue(), "UTF-8");
if (!url.contains("?")) {
url += "?" + key + "=" + value;
} else {
url += "&" + key + "=" + value;
}
}
}
HttpURLConnection urlConnection = (HttpURLConnection) new URL(url).openConnection();
urlConnection.setUseCaches(false);
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // handle url encoded form data
urlConnection.setRequestProperty("charset", "utf-8");
if (method == METHOD_GET) {
urlConnection.setRequestMethod("GET");
} else if (method == METHOD_POST) {
urlConnection.setDoOutput(true); // write POST params
urlConnection.setRequestMethod("POST");
}
//write POST data
if (method == METHOD_POST && params != null) {
StringBuilder postData = new StringBuilder();
for (Map.Entry < String, String > item: params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(item.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(item.getValue()), "UTF-8"));
}
byte[] postDataBytes = postData.toString().getBytes("UTF-8");
urlConnection.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
urlConnection.getOutputStream().write(postDataBytes);
}
// server response code
int responseCode = urlConnection.getResponseCode();
if (responseCode == HTTP_OK && callback != null) {
BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
// callback success
callback.OnSuccess(response.toString());
reader.close(); // close BufferReader
} else if (callback != null) {
// callback error
callback.OnError(responseCode, urlConnection.getResponseMessage());
}
urlConnection.disconnect(); // disconnect connection
} catch (IOException e) {
e.printStackTrace();
if (callback != null) {
// callback error
callback.OnError(500, e.getLocalizedMessage());
}
}
}
}).start(); // start thread
}
}
I see some other answers have given the alternative, I personally think that intuitively you're doing the right thing ;). Sorry, at devoxx where several speakers have been ranting about this sort of thing.
That's why I personally use Apache's HTTPClient/HttpCore libraries to do this sort of work, I find their API to be easier to use than Java's native HTTP support. YMMV of course!
GET and POST method set like this... Two types for api calling 1)get() and 2) post() . get() method to get value from api json array to get value & post() method use in our data post in url and get response.
public class HttpClientForExample {
private final String USER_AGENT = "Mozilla/5.0";
public static void main(String[] args) throws Exception {
HttpClientExample http = new HttpClientExample();
System.out.println("Testing 1 - Send Http GET request");
http.sendGet();
System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();
}
// HTTP GET request
private void sendGet() throws Exception {
String url = "http://www.google.com/search?q=developer";
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);
// add request header
request.addHeader("User-Agent", USER_AGENT);
HttpResponse response = client.execute(request);
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " +
response.getStatusLine().getStatusCode());
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}
System.out.println(result.toString());
}
// HTTP POST request
private void sendPost() throws Exception {
String url = "https://selfsolve.apple.com/wcResults.do";
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
// add header
post.setHeader("User-Agent", USER_AGENT);
List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM"));
urlParameters.add(new BasicNameValuePair("cn", ""));
urlParameters.add(new BasicNameValuePair("locale", ""));
urlParameters.add(new BasicNameValuePair("caller", ""));
urlParameters.add(new BasicNameValuePair("num", "12345"));
post.setEntity(new UrlEncodedFormEntity(urlParameters));
HttpResponse response = client.execute(post);
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + post.getEntity());
System.out.println("Response Code : " +
response.getStatusLine().getStatusCode());
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}
System.out.println(result.toString());
}
}
I had the same issue. I wanted to send data via POST.
I used the following code:
URL url = new URL("http://example.com/getval.php");
Map<String,Object> params = new LinkedHashMap<>();
params.put("param1", param1);
params.put("param2", param2);
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
String urlParameters = postData.toString();
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
String result = "";
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = reader.readLine()) != null) {
result += line;
}
writer.close();
reader.close()
System.out.println(result);
I used Jsoup for parse:
Document doc = Jsoup.parseBodyFragment(value);
Iterator<Element> opts = doc.select("option").iterator();
for (;opts.hasNext();) {
Element item = opts.next();
if (item.hasAttr("value")) {
System.out.println(item.attr("value"));
}
}
Try this pattern:
public static PricesResponse getResponse(EventRequestRaw request) {
// String urlParameters = "param1=a&param2=b&param3=c";
String urlParameters = Piping.serialize(request);
HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters);
PricesResponse response = null;
try {
// POST
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
// RESPONSE
BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8));
String json = Buffering.getString(reader);
response = (PricesResponse) Piping.deserialize(json, PricesResponse.class);
writer.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
conn.disconnect();
System.out.println("PricesClient: " + response.toString());
return response;
}
public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) {
return RestClient.getConnection(endPoint, "POST", urlParameters);
}
public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) {
System.out.println("ENDPOINT " + endPoint + " METHOD " + method);
HttpURLConnection conn = null;
try {
URL url = new URL(endPoint);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(method);
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/plain");
} catch (IOException e) {
e.printStackTrace();
}
return conn;
}
This answer covers the specific case of the POST Call using a Custom Java POJO.
Using maven dependency for Gson to serialize our Java Object to JSON.
Install Gson using the dependency below.
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.5</version>
<scope>compile</scope>
</dependency>
For those using gradle can use the below
dependencies {
implementation 'com.google.code.gson:gson:2.8.5'
}
Other imports used:
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.*;
import org.apache.http.impl.client.CloseableHttpClient;
import com.google.gson.Gson;
Now, we can go ahead and use the HttpPost provided by Apache
private CloseableHttpClient httpclient = HttpClients.createDefault();
HttpPost httppost = new HttpPost("https://example.com");
Product product = new Product(); //custom java object to be posted as Request Body
Gson gson = new Gson();
String client = gson.toJson(product);
httppost.setEntity(new StringEntity(client, ContentType.APPLICATION_JSON));
httppost.setHeader("RANDOM-HEADER", "headervalue");
//Execute and get the response.
HttpResponse response = null;
try {
response = httpclient.execute(httppost);
} catch (IOException e) {
throw new InternalServerErrorException("Post fails");
}
Response.Status responseStatus = Response.Status.fromStatusCode(response.getStatusLine().getStatusCode());
return Response.status(responseStatus).build();
The above code will return with the response code received from the POST Call
here i sent jsonobject as parameter //jsonobject={"name":"lucifer","pass":"abc"}//serverUrl = "http://192.168.100.12/testing" //host=192.168.100.12
public static String getJson(String serverUrl,String host,String jsonobject){
StringBuilder sb = new StringBuilder();
String http = serverUrl;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(http);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setUseCaches(false);
urlConnection.setConnectTimeout(50000);
urlConnection.setReadTimeout(50000);
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Host", host);
urlConnection.connect();
//You Can also Create JSONObject here
OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
out.write(jsonobject);// here i sent the parameter
out.close();
int HttpResult = urlConnection.getResponseCode();
if (HttpResult == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(
urlConnection.getInputStream(), "utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
Log.e("new Test", "" + sb.toString());
return sb.toString();
} else {
Log.e(" ", "" + urlConnection.getResponseMessage());
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (urlConnection != null)
urlConnection.disconnect();
}
return null;
}
Hello pls use this class to improve your post method
public static JSONObject doPostRequest(HashMap<String, String> data, String url) {
try {
RequestBody requestBody;
MultipartBuilder mBuilder = new MultipartBuilder().type(MultipartBuilder.FORM);
if (data != null) {
for (String key : data.keySet()) {
String value = data.get(key);
Utility.printLog("Key Values", key + "-----------------" + value);
mBuilder.addFormDataPart(key, value);
}
} else {
mBuilder.addFormDataPart("temp", "temp");
}
requestBody = mBuilder.build();
Request request = new Request.Builder()
.url(url)
.post(requestBody)
.build();
OkHttpClient client = new OkHttpClient();
Response response = client.newCall(request).execute();
String responseBody = response.body().string();
Utility.printLog("URL", url);
Utility.printLog("Response", responseBody);
return new JSONObject(responseBody);
} catch (UnknownHostException | UnsupportedEncodingException e) {
JSONObject jsonObject=new JSONObject();
try {
jsonObject.put("status","false");
jsonObject.put("message",e.getLocalizedMessage());
} catch (JSONException e1) {
e1.printStackTrace();
}
Log.e(TAG, "Error: " + e.getLocalizedMessage());
} catch (Exception e) {
e.printStackTrace();
JSONObject jsonObject=new JSONObject();
try {
jsonObject.put("status","false");
jsonObject.put("message",e.getLocalizedMessage());
} catch (JSONException e1) {
e1.printStackTrace();
}
Log.e(TAG, "Other Error: " + e.getLocalizedMessage());
}
return null;
}
I higly recomend http-request built on apache http api.
For your case you can see example:
private static final HttpRequest<String.class> HTTP_REQUEST =
HttpRequestBuilder.createPost("http://example.com/index.php", String.class)
.responseDeserializer(ResponseDeserializer.ignorableDeserializer())
.build();
public void sendRequest(String request){
String parameters = request.split("\\?")[1];
ResponseHandler<String> responseHandler =
HTTP_REQUEST.executeWithQuery(parameters);
System.out.println(responseHandler.getStatusCode());
System.out.println(responseHandler.get()); //prints response body
}
If you are not interested in the response body
private static final HttpRequest<?> HTTP_REQUEST =
HttpRequestBuilder.createPost("http://example.com/index.php").build();
public void sendRequest(String request){
ResponseHandler<String> responseHandler =
HTTP_REQUEST.executeWithQuery(parameters);
}
For general sending post request with http-request: Read the documentation and see my answers HTTP POST request with JSON String in JAVA, Sending HTTP POST Request In Java, HTTP POST using JSON in Java
I took Boann's answer and used it to create a more flexible query string builder that supports lists and arrays, just like php's http_build_query method:
public static byte[] httpBuildQueryString(Map<String, Object> postsData) throws UnsupportedEncodingException {
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : postsData.entrySet()) {
if (postData.length() != 0) postData.append('&');
Object value = param.getValue();
String key = param.getKey();
if(value instanceof Object[] || value instanceof List<?>)
{
int size = value instanceof Object[] ? ((Object[])value).length : ((List<?>)value).size();
for(int i = 0; i < size; i++)
{
Object val = value instanceof Object[] ? ((Object[])value)[i] : ((List<?>)value).get(i);
if(i>0) postData.append('&');
postData.append(URLEncoder.encode(key + "[" + i + "]", "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(val), "UTF-8"));
}
}
else
{
postData.append(URLEncoder.encode(key, "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(value), "UTF-8"));
}
}
return postData.toString().getBytes("UTF-8");
}
For those having trouble receiving the request on a php page using $_POST because you expect key-value pairs:
While all the answers where very helpful, I lacked some basic understanding on which string actually to post, since in the old apache HttpClient I used
new UrlEncodedFormEntity(nameValuePairs); (Java)
and then could use $_POST in php do get the key-value pairs.
To my understanding now one has build that string manually before posting. So the string needs to look like
val data = "key1=val1&key2=val2"
but instead just adding it to the url it is posted (in the header).
The alternative would be to use a json-string instead:
val data = "{\"key1\":\"val1\",\"key2\":\"val2\"}" // {"key1":"val1","key2":"val2"}
and pull it in php without $_POST:
$json_params = file_get_contents('php://input');
// echo_p("Data: $json_params");
$data = json_decode($json_params, true);
Here you find a sample code in Kotlin:
class TaskDownloadTest : AsyncTask<Void, Void, Void>() {
override fun doInBackground(vararg params: Void): Void? {
var urlConnection: HttpURLConnection? = null
try {
val postData = JsonObject()
postData.addProperty("key1", "val1")
postData.addProperty("key2", "val2")
// reformat json to key1=value1&key2=value2
// keeping json because I may change the php part to interpret json requests, could be a HashMap instead
val keys = postData.keySet()
var request = ""
keys.forEach { key ->
// Log.i("data", key)
request += "$key=${postData.get(key)}&"
}
request = request.replace("\"", "").removeSuffix("&")
val requestLength = request.toByteArray().size
// Warning in Android 9 you need to add a line in the application part of the manifest: android:usesCleartextTraffic="true"
// https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted
val url = URL("http://10.0.2.2/getdata.php")
urlConnection = url.openConnection() as HttpURLConnection
// urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded") // apparently default
// Not sure what these are for, I do not use them
// urlConnection.setRequestProperty("Content-Type", "application/json")
// urlConnection.setRequestProperty("Key","Value")
urlConnection.readTimeout = 5000
urlConnection.connectTimeout = 5000
urlConnection.requestMethod = "POST"
urlConnection.doOutput = true
// urlConnection.doInput = true
urlConnection.useCaches = false
urlConnection.setFixedLengthStreamingMode(requestLength)
// urlConnection.setChunkedStreamingMode(0) // if you do not want to handle request length which is fine for small requests
val out = urlConnection.outputStream
val writer = BufferedWriter(
OutputStreamWriter(
out, "UTF-8"
)
)
writer.write(request)
// writer.write("{\"key1\":\"val1\",\"key2\":\"val2\"}") // {"key1":"val1","key2":"val2"} JsonFormat or just postData.toString() for $json_params=file_get_contents('php://input'); json_decode($json_params, true); in php
// writer.write("key1=val1&key2=val2") // key=value format for $_POST in php
writer.flush()
writer.close()
out.close()
val code = urlConnection.responseCode
if (code != 200) {
throw IOException("Invalid response from server: $code")
}
val rd = BufferedReader(
InputStreamReader(
urlConnection.inputStream
)
)
var line = rd.readLine()
while (line != null) {
Log.i("data", line)
line = rd.readLine()
}
} catch (e: Exception) {
e.printStackTrace()
} finally {
urlConnection?.disconnect()
}
return null
}
}
Now I had to do an HTTP request class, it is probably not the most efficient class, but it works.
I collected some codes from this page and made it more dynamic.
Anyone who needs a complete code, I attached it below.
For an example of how to use it, you can look at the main method.
Also, if you are willing to improve classes online, you are more than welcome to help me make this class better.
import java.net.*;
import java.util.*;
import java.nio.charset.*;
import java.io.*;
public class HttpRequest {
String result = "";
HttpRequest(String _url, String _method, Map<String, String> _postData, String _contentType) {
try {
URL url = new URL( _url );
URLConnection con = url.openConnection();
HttpURLConnection http = (HttpURLConnection)con;
http.setRequestMethod(_method); // PUT is another valid option
http.setDoOutput(true);
StringJoiner sj = new StringJoiner("&");
for(Map.Entry<String,String> entry : _postData.entrySet())
sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + entry.getValue());
//sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + URLEncoder.encode(entry.getValue()));
byte[] out = sj.toString().getBytes(StandardCharsets.UTF_8);
int length = out.length;
http.setFixedLengthStreamingMode(length);
http.setRequestProperty("Content-Type", _contentType);
http.setRequestProperty( "charset", "utf-8");
http.setRequestProperty( "Content-Length", Integer.toString( length ));
http.setInstanceFollowRedirects( false );
http.setUseCaches( false );
http.connect();
try(OutputStream os = http.getOutputStream()) {
os.write(out);
}
if (http.getResponseCode() == HttpURLConnection.HTTP_OK) {
try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(http.getInputStream()))) {
String line;
while ((line = bufferedReader.readLine()) != null) {
result = result + line;
}
}
} else {
System.out.println("Bad response!");
}
}catch (IOException e) {
// writing exception to log
e.printStackTrace();
}
}
HttpRequest(String _url, String _method, Map<String, String> _postData) {
this(_url, _method, _postData, "text/html");
}
HttpRequest(String _url, String _method) {
this(_url, _method, new HashMap<String, String>());
}
HttpRequest(String _url) {
this(_url, "GET");
}
public String toString() {
return result;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Map<String, String> postData = new HashMap<String, String>();
postData.putIfAbsent("email", "test#test.com");
postData.putIfAbsent("password", "test");
HttpRequest result = new HttpRequest("https://httpbin.org/anything", "POST", postData, "application/x-www-form-urlencoded");
System.out.println(result.toString());
}
}
Appears that you also have to callconnection.getOutputStream() "at least once" (as well as setDoOutput(true)) for it to treat it as a POST.
So the minimum required code is:
URL url = new URL(urlString);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//connection.setRequestMethod("POST"); this doesn't seem to do anything at all..so not useful
connection.setDoOutput(true); // set it to POST...not enough by itself however, also need the getOutputStream call...
connection.connect();
connection.getOutputStream().close();
You can even use "GET" style parameters in the urlString, surprisingly. Though that might confuse things.
You can also use NameValuePair apparently.

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