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¶m2=b¶m3=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¶m2=b¶m3=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¶m2=b¶m3=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¶m2=b¶m3=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.
I want to create a java application that automatically logs into a website and does stuff. I'm testing it on my localhost. I'm actually totally new at this and I'm trying to get the concept from http://www.mkyong.com/java/how-to-automate-login-a-website-java-example/ and modifying the code to actually work for my localhost.
package random;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class InternetAutomationPost {
List<String> cookies;
public void setCookies(List<String> cookies) {
this.cookies = cookies;
}
public List<String> getCookies() {
return cookies;
}
private String requestWebPage(String address) {
try {
URL url = new URL(address);
HttpURLConnection con = (HttpURLConnection)url.openConnection();
// Don't use cache. Get a fresh copy.
con.setUseCaches(false);
// Use post or get.
// And default is get.
con.setRequestMethod("GET");
// Mimic a web browser.
con.addRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
con.addRequestProperty("Accept-Encoding", "gzip,deflate,sdch");
con.addRequestProperty("Accept-Language", "en-US,en;q=0.8");
con.addRequestProperty("Connection", "keep-alive");
con.addRequestProperty("User-Agent", "Mozilla/5.0");
if(cookies != null) {
con.addRequestProperty("Cache-Control", "max-age=0");
for (String cookie : this.cookies) {
System.out.print(cookie.split(";", 1)[0]);
con.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
}
}
int responseCode = con.getResponseCode();
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " + responseCode);
BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while( (inputLine = br.readLine()) != null) {
response.append(inputLine);
}
br.close();
// Get the response cookies
setCookies(con.getHeaderFields().get("Set-Cookie"));
return response.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return "";
}
private String parsePage(String page) {
Document doc;
try {
doc = Jsoup.parse(page);
Elements form = doc.getElementsByAttributeValue("action", "login.php");
List<String> paramList = new ArrayList<String>();
for(Element loginForm : form) {
System.out.println(loginForm.html());
Elements Input = loginForm.getElementsByTag("input");
for(Element input : Input) {
String name = input.attr("name");
String value = input.attr("value");
if(name.equals("email")) {
value = "admin#admin.com";
} else if(name.equals("password")) {
value = "password";
} else if(name.equals("")) {
continue;
}
paramList.add(name + "=" + URLEncoder.encode(value, "UTF-8"));
}
}
StringBuilder params = new StringBuilder();
for(String values : paramList) {
if(params.length() == 0) {
params.append(values);
} else {
params.append("&" + values);
}
}
System.out.println("Params: " + params);
return params.toString();
} catch (IOException e) {
e.printStackTrace();
}
return "";
}
private void sendPostLogin(String location, String params) {
try {
URL url = new URL(location);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
// Don't use cache. Get a fresh copy.
con.setUseCaches(false);
// Use post or get. We use post this time.
con.setRequestMethod("POST");
// Mimic a web browser.
con.addRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
con.addRequestProperty("Accept-Encoding", "gzip,deflate,sdch");
con.addRequestProperty("Accept-Language", "en-US,en;q=0.8");
con.addRequestProperty("Connection", "keep-alive");
con.addRequestProperty("User-Agent", "Mozilla/5.0");
if(cookies != null) {
con.addRequestProperty("Cache-Control", "max-age=0");
for (String cookie : this.cookies) {
con.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
}
}
con.addRequestProperty("Content-Length", Integer.toString(params.length()));
con.addRequestProperty("Content-Type", "application/x-www-form-urlencoded");
con.addRequestProperty("Host", "localhost");
con.addRequestProperty("Origin", "http://localhost");
con.addRequestProperty("Referrer", "http://localhost/social/index.php");
con.setDoOutput(true);
con.setDoInput(true);
// Write the parameters. Send post request.
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(params);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + params);
System.out.println("Response Code : " + responseCode);
BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while( (inputLine = br.readLine()) != null) {
response.append(inputLine);
}
br.close();
// Get the response cookies
setCookies(con.getHeaderFields().get("Set-Cookie"));
System.out.println(response.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* #param args
*/
public static void main(String[] args) {
InternetAutomationPost object = new InternetAutomationPost();
String page = object.requestWebPage("http://localhost/social");
String params = object.parsePage(page);
object.sendPostLogin("http://localhost/social/index.php", params);
}
}
EDIT:
Found out why it sent HTTP response code: 413.
con.addRequestProperty("Content-Length:", Integer.toString(params.length()));
should have been:
con.addRequestProperty("Content-Length", Integer.toString(params.length()));
There was a stray ':'. I've fixed it now.
BUT, still my code doesn't actually login and I still need help .
I have put my full program here now.
I might be wrong but I'm thinking that the params aren't actually getting written to the con.getOutputStream() in the code here:
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(params);
wr.flush();
wr.close();
You set the Content-Length to Integer.toString(params.length())
My guess would be, that your params written as bytes are longer than the Content-Length and your server receives more bytes than expected.
Try:
con.addRequestProperty("Content-Length:", Integer.toString(params.getBytes("UTF-8").length()));
This depends on your encoding obviously. Also have a look at this.
I would like to generate POST request to a server which requires authentication. I tried to use the following method:
private synchronized String CreateNewProductPOST (String urlString, String encodedString, String title, String content, Double price, String tags) {
String data = "product[title]=" + URLEncoder.encode(title) +
"&product[content]=" + URLEncoder.encode(content) +
"&product[price]=" + URLEncoder.encode(price.toString()) +
"&tags=" + tags;
try {
URL url = new URL(urlString);
URLConnection conn;
conn = url.openConnection();
conn.setRequestProperty ("Authorization", "Basic " + encodedString);
conn.setDoOutput(true);
conn.setDoInput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
// Get the response
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
// Process line...
}
wr.close();
rd.close();
return rd.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
return e.getMessage();
}
catch (IOException e) {
e.printStackTrace();
return e.getMessage();
}
}
but the server doesn't receive the authorization data. The line which is supposed to add authorization data is the following:
conn.setRequestProperty ("Authorization", "Basic " + encodedString);
and the line
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
also throws an IOException.
Anyway I would be very thankful if anyone could suggest any fix of the logic above in order to enable authorization using POST with UrlConnection.
but obviously it doesn't work as it is supposed to although if the same logic is used for GET request everything works fine.
A fine example found here. Powerlord got it right, below, for POST you need HttpURLConnection, instead.
Below is the code to do that,
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
conn.setRequestProperty ("Authorization", encodedCredentials);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(data);
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();
Change URLConnection to HttpURLConnection, to make it POST request.
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
Suggestion (...in comments):
You might need to set these properties too,
conn.setRequestProperty( "Content-type", "application/x-www-form-urlencoded");
conn.setRequestProperty( "Accept", "*/*" );
I don't see anywhere in the code where you specify that this is a POST request. Then again, you need a java.net.HttpURLConnection to do that.
In fact, I highly recommend using HttpURLConnection instead of URLConnection, with conn.setRequestMethod("POST"); and see if it still gives you problems.
To do oAuth authentication to external app (INSTAGRAM) Step 3 "get the token after receiving the code" Only code below worked for me
Worth to state also that it worked for me using some localhost URL with a callback servlet configured with name "callback in web.xml and callback URL registered: e.g. localhost:8084/MyAPP/docs/insta/callback
BUT after successfully completed authentication steps, using same external site "INSTAGRAM" to do GET of Tags or MEDIA to retrieve JSON data using initial method didn't work.
Inside my servlet to do GET using url like
e.g. api.instagram.com/v1/tags/MYTAG/media/recent?access_token=MY_TOKEN only method found HERE worked
Thanks to all contributors
URL url = new URL(httpurl);
HashMap<String, String> params = new HashMap<String, String>();
params.put("client_id", id);
params.put("client_secret", secret);
params.put("grant_type", "authorization_code");
params.put("redirect_uri", redirect);
params.put("code", code); // your INSTAGRAM code received
Set set = params.entrySet();
Iterator i = set.iterator();
StringBuilder postData = new StringBuilder();
for (Map.Entry<String, String> 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");
HttpsURLConnection conn = (HttpsURLConnection) 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);
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
StringBuilder builder = new StringBuilder();
for (String line = null; (line = reader.readLine()) != null;) {
builder.append(line).append("\n");
}
reader.close();
conn.disconnect();
System.out.println("INSTAGRAM token returned: "+builder.toString());
To send a POST request call:
connection.setDoOutput(true); // Triggers POST.
If you want to sent text in the request use:
java.io.OutputStreamWriter wr = new java.io.OutputStreamWriter(connection.getOutputStream());
wr.write(textToSend);
wr.flush();
I ran into this problem today and none of the solutions posted here worked. However, the code posted here worked for a POST request:
// HTTP POST request
private void sendPost() throws Exception {
String url = "https://selfsolve.apple.com/wcResults.do";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
//print result
System.out.println(response.toString());
}
It turns out that it's not the authorization that's the problem. In my case, it was an encoding problem. The content-type I needed was application/json but from the Java documentation:
static String encode(String s, String enc)
Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.
The encode function translates the string into application/x-www-form-urlencoded.
Now if you don't set a Content-Type, you may get a 415 Unsupported Media Type error. If you set it to application/json or anything that's not application/x-www-form-urlencoded, you get an IOException. To solve this, simply avoid the encode method.
For this particular scenario, the following should work:
String data = "product[title]=" + title +
"&product[content]=" + content +
"&product[price]=" + price.toString() +
"&tags=" + tags;
Another small piece of information that might be helpful as to why the code breaks when creating the buffered reader is because the POST request actually only gets executed when conn.getInputStream() is called.
On API 22 The Use Of BasicNamevalue Pair is depricated, instead use the HASMAP for that. To know more about the HasMap visit here more on hasmap developer.android
package com.yubraj.sample.datamanager;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import com.yubaraj.sample.utilities.GeneralUtilities;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import javax.net.ssl.HttpsURLConnection;
/**
* Created by yubraj on 7/30/15.
*/
public class ServerRequestHandler {
private static final String TAG = "Server Request";
OnServerRequestComplete listener;
public ServerRequestHandler (){
}
public void doServerRequest(HashMap<String, String> parameters, String url, int requestType, OnServerRequestComplete listener){
debug("ServerRequest", "server request called, url = " + url);
if(listener != null){
this.listener = listener;
}
try {
new BackgroundDataSync(getPostDataString(parameters), url, requestType).execute();
debug(TAG , " asnyc task called");
} catch (Exception e) {
e.printStackTrace();
}
}
public void doServerRequest(HashMap<String, String> parameters, String url, int requestType){
doServerRequest(parameters, url, requestType, null);
}
public interface OnServerRequestComplete{
void onSucess(Bundle bundle);
void onFailed(int status_code, String mesage, String url);
}
public void setOnServerRequestCompleteListener(OnServerRequestComplete listener){
this.listener = listener;
}
private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
StringBuilder result = new StringBuilder();
boolean first = true;
for(Map.Entry<String, String> entry : params.entrySet()){
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
return result.toString();
}
class BackgroundDataSync extends AsyncTask<String, Void , String>{
String params;
String mUrl;
int request_type;
public BackgroundDataSync(String params, String url, int request_type){
this.mUrl = url;
this.params = params;
this.request_type = request_type;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String... urls) {
debug(TAG, "in Background, urls = " + urls.length);
HttpURLConnection connection;
debug(TAG, "in Background, url = " + mUrl);
String response = "";
switch (request_type) {
case 1:
try {
connection = iniitializeHTTPConnection(mUrl, "POST");
OutputStream os = connection.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(params);
writer.flush();
writer.close();
os.close();
int responseCode = connection.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
/* String line;
BufferedReader br=new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((line=br.readLine()) != null) {
response+=line;
}*/
response = getDataFromInputStream(new InputStreamReader(connection.getInputStream()));
} else {
response = "";
}
} catch (IOException e) {
e.printStackTrace();
}
break;
case 0:
connection = iniitializeHTTPConnection(mUrl, "GET");
try {
if (connection.getResponseCode() == connection.HTTP_OK) {
response = getDataFromInputStream(new InputStreamReader(connection.getInputStream()));
}
} catch (Exception e) {
e.printStackTrace();
response = "";
}
break;
}
return response;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if(TextUtils.isEmpty(s) || s.length() == 0){
listener.onFailed(DbConstants.NOT_FOUND, "Data not found", mUrl);
}
else{
Bundle bundle = new Bundle();
bundle.putInt(DbConstants.STATUS_CODE, DbConstants.HTTP_OK);
bundle.putString(DbConstants.RESPONSE, s);
bundle.putString(DbConstants.URL, mUrl);
listener.onSucess(bundle);
}
//System.out.println("Data Obtained = " + s);
}
private HttpURLConnection iniitializeHTTPConnection(String url, String requestType) {
try {
debug("ServerRequest", "url = " + url + "requestType = " + requestType);
URL link = new URL(url);
HttpURLConnection conn = (HttpURLConnection) link.openConnection();
conn.setRequestMethod(requestType);
conn.setDoInput(true);
conn.setDoOutput(true);
return conn;
}
catch(Exception e){
e.printStackTrace();
}
return null;
}
}
private String getDataFromInputStream(InputStreamReader reader){
String line;
String response = "";
try {
BufferedReader br = new BufferedReader(reader);
while ((line = br.readLine()) != null) {
response += line;
debug("ServerRequest", "response length = " + response.length());
}
}
catch (Exception e){
e.printStackTrace();
}
return response;
}
private void debug(String tag, String string) {
Log.d(tag, string);
}
}
and Just call the function when you needed to get the data from server either by post or get like this
HashMap<String, String>params = new HashMap<String, String>();
params.put("action", "request_sample");
params.put("name", uname);
params.put("message", umsg);
params.put("email", getEmailofUser());
params.put("type", "bio");
dq.doServerRequest(params, "your_url", DbConstants.METHOD_POST);
dq.setOnServerRequestCompleteListener(new ServerRequestHandler.OnServerRequestComplete() {
#Override
public void onSucess(Bundle bundle) {
debug("data", bundle.getString(DbConstants.RESPONSE));
}
#Override
public void onFailed(int status_code, String mesage, String url) {
debug("sample", mesage);
}
});
Now it is complete.Enjoy!!! Comment it if find any problem.
HTTP authorization does not differ between GET and POST requests, so I would first assume that something else is wrong. Instead of setting the Authorization header directly, I would suggest using the java.net.Authorization class, but I am not sure if it solves your problem. Perhaps your server is somehow configured to require a different authorization scheme than "basic" for post requests?
i was looking information about how to do a POST request. I need to specify that mi request is a POST request because, i'm working with RESTful web services that only uses POST methods, and if the request isn't post, when i try to do the request i receive an HTTP error 405. I assure that my code isn't wrong doing the next: I create a method in my web service that is called through GET request and i point my application to consume that web service method and it works.
My code is the next:
URL server = null;
URLConnection conexion = null;
BufferedReader reader = null;
server = new URL("http://localhost:8089/myApp/resources/webService");
conexion = server.openConnection();
reader = new BufferedReader(new InputStreamReader(server.openStream()));
System.out.println(reader.readLine());