We Keep Coding

Does Java URLConnection send Metadata?

when you open a connection via URLConnection to read the content of a Webpage,
try {
URL url = new URL("https://stackoverflow.com/questions/46939965/does-java-urlconnection-send-metadata");
URLConnection urlConnection = url.openConnection();
HttpURLConnection connection;
connection = (HttpURLConnection) urlConnection;
BufferedReader in = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
String current;
while((current = in.readLine()) != null) {
urlString += current;
}
}catch(IOException e) {
e.printStackTrace();
}
what will Java leave for Information?
Will statistical data like the Webbrowser saved? Will that be the "Java"?
Thx for help,
~Corn

HTTP "metadata" is normally sent in the headers. The one that would indicate the web browser is typically called "USER_AGENT." I do not believe Java will populate these headers for you implicitly.

Android : BufferedReader InputStreamReader returning old value

In my android application am reading text file which is in server.
Am using below method.
private String getUrlContents(String UrlOfFile)
{
StringBuilder content = new StringBuilder();
try
{
URL url = new URL(UrlOfFile);
URLConnection urlConnection = url.openConnection();
BufferedReader bufferedReader = new BufferedReader(new
InputStreamReader(urlConnection.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null)
{
content.append(line + "\n");
}
bufferedReader.close();
}
catch(Exception e)
{
Log.d(TAG,"Exception >>>"+Log.getStackTraceString(e));
}
return content.toString();
}
But I am getting previous value of text file. When I once do clear data of app its able to get actual value.
Please help me to solve this issue.

My problem was due to returning of cached response.
Issue solved by urlConnection.setUseCaches(false);
Thanks to all responds,
How to prevent Android from returning a cached response to my HTTP Request?
Adding header for HttpURLConnection

Issue with Retrieving JSON from Webpage Android

So I'm facing some difficulty in trying to, what seems simply, obtain a JSON file from a webpage, and then parse it on Android. I have already built the parser, and tested it in Eclipse (in fact, all of the code works in Eclipse). However, when I run the HttpURLConnection and try to retrieve the JSON data in a string in Android Studio, I end up getting no exceptions and an almost empty string (I think I am getting the 1st, 2nd, 3rd, and last character, but not too sure). I have included parts of the code below, and
URL url = null;
HttpURLConnection urc = null;
try {
url = new URL(query);
urc = (HttpURLConnection) url.openConnection();
InputStream in = new BufferedInputStream(urc.getInputStream());
jsoncontent = readStream(in);
System.out.println(jsoncontent);
} catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
urc.disconnect();
}
The code for readStream() is below
private static String readStream(InputStream is) throws IOException {
StringBuilder sb = new StringBuilder();
BufferedReader r = new BufferedReader(new InputStreamReader(is),1000);
for (String line = r.readLine(); line != null; line =r.readLine()){
sb.append(line);
}
is.close();
return sb.toString();
}

Here is an exact chunk from an assignment I did last semester:
URL u = new URL(url);
HttpURLConnection conn = (HttpURLConnection) u.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "text/html");
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
JSONObject searchResults = new JSONObject(in.readLine());
...
conn.disconnect();
You seem to be missing setRequestMethod("GET") and setRequestProperty("Accept", "text/html") in your code. Hope this helps.

Java CURL request using HTTP

I am trying to perform a CURL request using Java. The CURL request is as follows:
curl https://apis.sen.se/v2/feeds/N4hSBSpFlYzXT6ZN2IA1KadgSR9rTazv/events/?limit=1 -u username:password
I am trying to perform the request as follows:
String stringUrl = "https://apis.sen.se/v2/feeds/N4hSBSpFlYzXT6ZN2IA1KadgSR9rTazv/events/?limit=1";
URL url = new URL(stringUrl);
URLConnection uc = url.openConnection();
uc.setRequestProperty("X-Requested-With", "Curl");
String userpass = "username" + ":" + "password";
String basicAuth = "Basic " + new String(new Base64().encode(userpass.getBytes()));
uc.setRequestProperty("Authorization", basicAuth);
InputStreamReader inputStreamReader = new InputStreamReader(uc.getInputStream());
and I am trying to see the contents of inputStreamReader as follows:
int data = inputStreamReader.read();
char aChar = (char) data;
System.out.println(aChar);
The code is compiling and running fine, but it is returning nothing. Where am I going wrong?

I ended up getting it working using the following code:
public static void main(String args[]) throws IOException {
String stringUrl = "url";
URL url = new URL(stringUrl);
URLConnection uc = url.openConnection();
uc.setRequestProperty("X-Requested-With", "Curl");
String userpass = "username" + ":" + "password";
String basicAuth = "Basic " + new String(new Base64().encode(userpass.getBytes()));
uc.setRequestProperty("Authorization", basicAuth);
StringBuilder html = new StringBuilder();
BufferedReader input = null;
try {
input = new BufferedReader(new InputStreamReader(uc.getInputStream()));
String htmlLine;
while ((htmlLine = input.readLine()) != null) {
html.append(htmlLine);
}
}
catch (IOException e) {
e.printStackTrace();
}
finally {
try {
input.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
System.out.println(html.toString());
}

I was also trying to do that thing. I have some kind of workaround but it reads everything it sees.
--Here's the code---
String params = "some-parameters";
URL url = new URL("some-website");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(params);
wr.flush();
wr.close();
con.getResponseCode();
BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line;
StringBuffer buffer = new StringBuffer();
while((line = reader.readLine()) != null) {
buffer.append(line+"\n");
}
reader.close();
System.out.print(buffer.toString());
--Notice, I use this code to see if a certain account exist on a certain website, since it outputs everything, what I do is to find a specific regularity upon the code which could tell me if that user exist or not. Well I'm not really even sure if this could help you, but it might be. Good Luck...

java servlet http url request

When I run this code from Java app I get correct response (UTF-8 encoded).
The problem is, when I run it from my servlet, I'm geting:
"פשטות הי� התחכו� המושל�"
ל×�×•× ×¨×“×• די סר פיירו דה ×•×™× ×¦'×™
Any idea how to fix it?
URL url;
HttpURLConnection conn;
BufferedReader rd;
String line;
String result = "";
try {
url=new URL("http://www.walla.co.il");
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuffer sb = new StringBuffer("");
String s1="";
String NL = System.getProperty("line.separator");
while ((s1 = rd.readLine()) != null)
sb.append(s1+NL);
System.out.println(sb);
rd.close();
return sb.toString();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return "";

set "JAVA_OPTS=%JAVA_OPTS% -Dfile.encoding=UTF8"
i run this from *.bat file in my tomcat\bin
and it fix the problem seems like i had to set the encode for tomcat/jvm
not 100% sure but it works now :)