Android HTTP Post Request doesn't work, but stock Java does? - java

So I have 2 codes which supposedly do the same. The one I'm using on Android however, returns the wrong HTML data. The stock Java one returns the correct data after sending the request. I have both codes here. Can you tell me (EVEN THOUGH I GAVE INTERNET PERMISSION TO ANDROID) why the Android one isn't working, while the stock Java one is working? This is the Android code:
EDIT: I FOUND THE FIX. If you're going to use a StringEntity to send such a String to the Server, you have to set the content to application/x-www-form-urlencoded. I've edited my code to show this:
public static String sendNamePostRequest(String urlString) {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(urlString);
StringBuffer sb = new StringBuffer();
try {
StringEntity se = new StringEntity(
"__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=%2FwEPDwULLTE3NDM5MzMwMzRkZA%3D%3D&__EVENTVALIDATION=%2FwEWBAL%2B%2B4CfBgK52%2BLYCQK1gpH7BAL0w%2FPHAQ%3D%3D&_nameTextBox=John&_zoekButton=Zoek&numberOfLettersField=3");
se.setContent("application/x-www-form-urlencoded");
post.setEntity();
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();
BufferedReader br = new BufferedReader(new InputStreamReader(
entity.getContent()));
String in = "";
while ((in = br.readLine()) != null) {
sb.append(in + "\n");
}
br.close();
} catch (Exception e) {
e.printStackTrace();
}
return sb.toString();
}
This is the stock Java code:
public String sendNamePostRequest(String urlString) {
StringBuffer sb = null;
try {
String data = "__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=%2FwEPDwULLTE3NDM5MzMwMzRkZA%3D%3D&__EVENTVALIDATION=%2FwEWBAL%2B%2B4CfBgK52%2BLYCQK1gpH7BAL0w%2FPHAQ%3D%3D&_nameTextBox=John&_zoekButton=Zoek&numberOfLettersField=3";
// String data = "";
URL requestUrl = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) requestUrl
.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestMethod("POST");
DataOutputStream dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(data);
dos.flush();
BufferedReader br = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String in = "";
sb = new StringBuffer();
while ((in = br.readLine()) != null) {
sb.append(in + "\n");
}
dos.close();
br.close();
} catch (Exception e) {
e.printStackTrace();
}
return sb.toString();
}

If the data is getting to the server, you might want to see what is happening there (logs, errors, exceptions, etc.) Other than that:
use can use HttpURLConnection, so you can have the exact same code
For HttpClient, not sure whey you are encoding the entity yourself. Use NameValuePair to set parameters, and HttpClient will encode them for you (correctly).

You can use NameValuePair and UrlEncodedFormEntity:
List<BasicNameValuePair> nvps = new ArrayList<BasicNameValuePair>();
nvps.add(new BasicNameValuePair(KEY1, VALUE1));
nvps.add(new BasicNameValuePair(KEY2, VALUE2));
UrlEncodedFormEntity p_entity = new UrlEncodedFormEntity(nvps,HTTP.UTF_8);
post.setEntity(p_entity);

Related

Sending a POST request to a server

I am trying to create my first android application that utilizes a REST api. My api is written in Node.JS and has already been tested using Postman, however, I am having trouble sending JSON data to my api.
#Override
protected String doInBackground(String... params) {
String data = "";
String urlName = params[0];
HttpURLConnection httpURLConnection = null;
try {
httpURLConnection = (HttpURLConnection) new URL(urlName).openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(httpURLConnection.getOutputStream());
wr.writeBytes(params[1]);
wr.flush();
wr.close();
InputStream in = httpURLConnection.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(in);
int inputStreamData = inputStreamReader.read();
while (inputStreamData != -1) {
char current = (char) inputStreamData;
inputStreamData = inputStreamReader.read();
data += current;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (httpURLConnection != null) {
httpURLConnection.disconnect();
}
}
return data;
}
I always reach the line that declares and initializes my DataOutputSteam and doesn't execute the code. I am not even getting a log that my Virtual device has visited my server at all.
I have included in the manifest XML both of these already.
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
Based on your logs, you're hitting a NetworkOnMainThreadException and that's preventing the network request from being executed (it's going into your catch block instead). This suggests you aren't calling your AsyncTask correctly - ensure that you're calling execute instead of calling doInBackground. See also here for more information on this general pattern.
Try this, it is for POST method that accept 2 parameter email and password.
Change it based on your requirement
URL url = new URL(Login_url);
HttpURLConnection conn = (HttpURLConnection) new URL(urlName).openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Accept" , "application/json");
conn.connect();
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("email", "Your_Email")
.appendQueryParameter("password","Your_Password");
String query = builder.build().getEncodedQuery();
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
code = conn.getResponseCode();
Log.e("Result", code + "");
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
Log.e("Result",result.toString());

HttpURLConnection update from Http Client

Hello I was wondering if somebody could help me with the following, I have a database that is currently populated. I used to call it using the http client and it worked fine but now I'm trying to update the code since its been deprecated to use the httpurlconnection but i have no success. I ve looked up some tutorials and tried a few thing but it doesn't seem to be working. the database is called through a php file and returns it in a json format.If i were to call the php file from my browser the response is the following: [{"id":"15","logo":"logo url","title":"title"}]
The error that I get on the console is the following:java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.InputStream.close()' on a null object reference
Which its not making much sense to me since the script pulls information
I have the following code, i left the commented section just in case i need any of it, It also includes the old way i used to call the DB Thank you!:
public void loadNews(){
InputStream is = null;
String result = "";
ArrayList<NameValuePair>();
try {
URL url = new URL("http://databasecall.php");
//HttpClient httpclient = new DefaultHttpClient();
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//urlConnection.setRequestMethod("GET");
//urlConnection.setRequestProperty("Content-length", "0");
//urlConnection.setUseCaches(false);
//urlConnection.setAllowUserInteraction(false);
//urlConnection.setConnectTimeout(15000);
//urlConnection.setReadTimeout(15000);
//urlConnection.connect();
int responseCode = urlConnection.getResponseCode();
Log.i("Tag:", Integer.toString(responseCode)); //tag 200
//HttpPost httppost = new HttpPost("http://databasecall.php");
//httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
//HttpResponse response = httpclient.execute(httppost);
//HttpEntity entity = response.getEntity();
//is = entity.getContent();
/*}catch(Exception e){
Log.e("log_tag", "Error in http connection "+e.toString());
}*/
//convert response to string
//try{
//BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
//BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
Log.i("Tag:", result);
}
}catch(Exception e){
Log.e("log_tag", "Error converting result " + e.toString());
}
Updated API
try {
String urlParameters = "name=toni&class=one&param3=ok";
byte[] postData = urlParameters.getBytes(Charset.forName("UTF-8"));
int postDataLength = postData.length;
String request = "http://rocks.php";
URL url = new URL(request);
HttpURLConnection cox = (HttpURLConnection) url.openConnection();
cox.setDoOutput(true);
cox.setDoInput(true);
cox.setInstanceFollowRedirects(false);
cox.setRequestMethod("POST");
cox.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
cox.setRequestProperty("charset", "utf-8");
cox.setRequestProperty("Content-Length",
Integer.toString(postDataLength));
cox.setUseCaches(false);
OutputStreamWriter writer = new OutputStreamWriter(
cox.getOutputStream());
writer.write(urlParameters);
writer.flush();
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(
cox.getInputStream()));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
writer.close();
reader.close();
} catch (Exception e) {
result = e.toString();
Sucess = false;
e.printStackTrace();
}

How to add header to HttpRequest of GET method in Java

I have to pass a token as part of validation for each GET request to access RESTful web service. Below is the code I'm using it to access REST api:
public static String httpGet(String urlStr, String[] paramName, String[] paramVal) throws Exception {
URL url = new URL(urlStr);
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
OutputStream out = conn.getOutputStream();
Writer writer = new OutputStreamWriter(out, "UTF-8");
for (int i = 0; i < paramName.length; i++) {
writer.write(paramName[i]);
writer.write("=");
writer.write(URLEncoder.encode(paramVal[i], "UTF-8"));
writer.write("&");
}
writer.close();
out.close();
if (conn.getResponseCode() != 200) {
System.out.println("Response code: "+conn.getResponseCode());
throw new IOException(conn.getResponseMessage());
}
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line;
while ((line = rd.readLine()) != null) {
sb.append(line);
}
rd.close();
conn.disconnect();
return sb.toString();
}
I can't see any such method to set Header conn.setHeader() provided for HttpsURLConnection. It should be something like X-Cookie: token={token}; please help me to find a way to set header.
You can use:
conn.addRequestProperty("X-Cookie", "token={token}");
or setRequestProperty() also works
You are already setting headers on your request in your code when you do the following:
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
I.e. if the service you are communicating with requires that you send your token in the "X-Cookie" header you can simply do the same for that header:
conn.setRequestProperty("X-Cookie", "token={token}");

JSON: "Unexpected character (<) at position 0"

Here's the twitch.tv api request to get channel summary: http://api.justin.tv/api/streams/summary.json?channel=mychannel. If I post it via browser, I get correct results. But programmatically I receive an exception during result parsing.
I use apache HttpClient to send requests and receive responses. And JSON-Simple to parse JSON content.
This is how I try to get JSON from response according to api:
HttpClient httpClient = HttpClients.createDefault();
HttpGet getRequest = new HttpGet(new URL("http://api.justin.tv/api/streams/summary.json?channel=mychannel").toURI());
getRequest.addHeader("Accept", "application/json");
HttpResponse response = httpClient.execute(getRequest);
BufferedReader br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String output;
StringBuilder builder = new StringBuilder();
while((output = br.readLine()) != null) {
builder.append(output);
}
br.close();
JSONParser parser = new JSONParser();
Object obj = parser.parse(builder.toString()); //Exception occurs here
Expected result: {"average_bitrate":0,"viewers_count":"0","streams_count":0}, but execution of example above leads to: Unexpected character (<) at position 0.
How to get JSON body from response? Browser displays the result correct.
Try this:
URL url = new URL("http://api.justin.tv/api/stream/summary.json?channel=mychannel");
HttpURLConnection request1 = (HttpURLConnection) url.openConnection();
request1.setRequestMethod("GET");
request1.connect();
InputStream is = request1.getInputStream();
BufferedReader bf_reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = bf_reader.readLine()) != null) {
sb.append(line).append("\n");
}
} catch (IOException e) {
} finally {
try {
is.close();
} catch (IOException e) {
}
}
String responseBody = sb.toString();
JSONParser parser = new JSONParser();
Object obj = parser.parse(responseBody);
System.out.println(obj);

how to pass the parameters to the urlconnection in java/android?

i can establish a connection using HttpUrlConnection. my code below.
client = new DefaultHttpClient();
URL action_url = new URL(actionUrl);
conn = (HttpURLConnection) action_url.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestProperty("userType", "2");
conn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
conn.setRequestMethod(HttpPost.METHOD_NAME);
DataOutputStream ds = new DataOutputStream(conn.getOutputStream());
String content = "username=username1&password=password11";
Log.v(TAG, "content: " + content);
ds.writeBytes(content);
ds.flush();
ds.close();
InputStream in = conn.getInputStream();//**getting filenotfound exception here.**
BufferedReader reader = new BufferedReader(
new InputStreamReader(in));
StringBuilder str1 = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
str1.append(line);
Log.v(TAG, "line:" + line);
}
in.close();
s = str1.toString();
getting filenotfound exception. dont know why?
else give me some suggestion to pass username and passwrod parameter to the url by code..
The HTTPClient offers a much simpler way to access http resources, when all you want to do is fetch the repsonse body:
HttpGet httpGet = new HttpGet("http://domain.com/path?var1=bla&var2=foo");
HTTPResponse reponse = httpClient.execute(httpGet);
String responseBody = EntityUtils.toString(response.getEntity());

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