Develop Reference

Upload File Using HTTP Post - Java

I have this current code. The file is in memory on the InputStream in or in test.pdf. I would prefer to only keep in-memory.
FileOutputStream fos = new FileOutputStream(new File("test.pdf"));
// Read file
InputStream in = url.openStream();
while((bufferLength = in.read(buffer)) != -1) {
fos.write(buffer, 0, bufferLength);
}
fos.flush();
// Close connections
fos.close();
in.close();
System.out.println("GOT DOCUMENT");
String submitURl = "https://someURL/submit";
// Send data
HttpURLConnection conn = (HttpURLConnection) new URL(submitURl).openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestProperty("Content-Type","multipart/form-data");
conn.setRequestProperty("User-Agent", "Test Agent");
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.flush();
How do I post this file to the /submit URL. What am I missing here?

HTTP Post request in Java for facebook is not working properly?

String httpsURL = "https://m.facebook.com/login/identify/?ctx=recover&c=https%3A%2F%2Fm.facebook.com%2Flogin%2F&lwv=100&_rdr";
String query = "email="+URLEncoder.encode("myemailaddress#gmail.com","UTF-8");
URL myurl = new URL(httpsURL);
HttpsURLConnection con = (HttpsURLConnection)myurl.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("Content-length", String.valueOf(query.length()));
con.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
con.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0;Windows98;DigExt)");
con.setDoOutput(true);
con.setDoInput(true);
DataOutputStream output = new DataOutputStream(con.getOutputStream());
output.writeBytes(query);
output.close();
DataInputStream input = new DataInputStream( con.getInputStream() );
for( int c = input.read(); c != -1; c = input.read() )
System.out.print( (char)c );
input.close();
System.out.println("Resp Code:"+con .getResponseCode());
System.out.println("Resp Message:"+ con .getResponseMessage());
![enter image description here](https://i.stack.imgur.com/gVUc3.png)![enter image description here](https://i.stack.imgur.com/3RihL.png)

I made the below 2 changes to your code to make it work:
1) Removed the _rdr parameter from the end of the URL. Looks like when you add that, it always redirects you to the initial page. So:
String httpsURL = "https://m.facebook.com/login/identify/?ctx=recover&c=https%3A%2F%2Fm.facebook.com%2Flogin%2F&lwv=100";
2) When following redirects, HttpsURLConnection doesn't set cookies it got from the original response, unless you do this (More info):
CookieHandler.setDefault(new CookieManager());
Putting these two together, we have the final working code below. Here is a working demo. I added BufferedReader to read the response for slightly better looking console output, this is not necessary for it to work.
String httpsURL = "https://m.facebook.com/login/identify/?ctx=recover&c=https%3A%2F%2Fm.facebook.com%2Flogin%2F&lwv=100";
String query = "email=" + URLEncoder.encode("myemailaddress#gmail.com", "UTF-8");
CookieHandler.setDefault(new CookieManager());
URL myurl = new URL(httpsURL);
HttpsURLConnection con = (HttpsURLConnection) myurl.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("Content-length", String.valueOf(query.length()));
con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
con.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0;Windows98;DigExt)");
con.setDoOutput(true);
con.setDoInput(true);
DataOutputStream output = new DataOutputStream(con.getOutputStream());
output.writeBytes(query);
output.close();
BufferedReader input = new BufferedReader(new InputStreamReader(con.getInputStream()));
for (int c = input.read(); c != -1; c = input.read())
System.out.print((char) c);
input.close();
System.out.println("Resp Code:" + con.getResponseCode());
System.out.println("Resp Message:" + con.getResponseMessage());

I want to post an xml to another server

When i run this code it gives me error xml stating---Problem processing POST request: unsupported Content-Type text/xml. I want to send an xml using httpClient to a URL which is a web service url
public class HTTPClientDemo {
public static void main(String[] args) {
try
{
String inputXML = "<Style>0206.ard</Style><BoardCode>I-175B</BoardCode><BoardDesc>I-175 B Kraft</BoardDesc><GrainDirection>Vertical</GrainDirection><Unit>mm</Unit><PrintSide>Inside</PrintSide><Length>100</Length><Width>70</Width><Depth>45</Depth>";
URL url = new URL( "http://egwinae002:4415/ws/wstest003" );
// URL url = new URL( "https://dzone.com/articles/using-java-post-block-xml-web" );
URLConnection con = url.openConnection();
// con.connect();
// specify that we will send output and accept input
con.setDoInput(true);
con.setDoOutput(true);
con.setConnectTimeout( 20000 ); // long timeout, but not infinite
con.setReadTimeout( 20000 );
con.setUseCaches (false);
con.setDefaultUseCaches (false);
// tell the web server what we are sending
con.setRequestProperty ( "Content-Type", "text/xml" );
OutputStreamWriter writer = new OutputStreamWriter( con.getOutputStream() );
writer.write( inputXML );
writer.flush();
writer.close();
// reading the response
InputStreamReader reader = new InputStreamReader( con.getInputStream() );
StringBuilder buf = new StringBuilder();
char[] cbuf = new char[ 2048 ];
int num;
while ( -1 != (num=reader.read( cbuf )))
{
buf.append( cbuf, 0, num );
}
String result = buf.toString();
System.err.println( "\nResponse from server after POST:\n" + result );
}
catch( Throwable t )
{
t.printStackTrace( System.out );
}

// Have done modification and added some lines in your code, hope it will work
URLConnection con = url.openConnection();
//Added this one to make your connection http
HttpURLConnection conn = (HttpURLConnection) con;
// con.connect();
// specify that we will send output and accept input
conn .setDoInput(true);
conn .setDoOutput(true);
conn .setRequestProperty("accept-charset", "UTF-8");
// tell the web server what we are sending
conn.setRequestProperty ( "Content-Type", "text/xml" );
// set data posting method
conn.setRequestMethod("POST");
// OutputStreamWriter writer = new OutputStreamWriter( conn.getOutputStream() );
PrintWriter writer = new PrintWriter(conn.getOutputStream());
writer.write( inputXML );
writer.close();
// reading the response
// InputStreamReader reader = new InputStreamReader( conn.getInputStream() );
BufferedInputStream reader = new BufferedInputStream(conn.getInputStream());

Unable to use GET Method

I am trying to write a code which will give me the contents of the page as the response in a string using GET method in java.
Below is the code I am using, its throwing me error that java.net.MalformedURLException: no protocol
If I try inserting http:// in starting of the URL its giving me Unknown Host Exception.
String request = ("http://gotoanswer.com/?q=What+is+the+Java+equivalent+for+the+following+in+curl%3F");
System.out.println(request);
URL url = null;
try{
new URL(request);
HttpURLConnection connection = (HttpURLConnection) new URL(request).openConnection();
connection.setDoOutput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("GET");
connection.setRequestProperty("Content-Type", "text/xml");
connection.setRequestProperty("charset", "utf-8");
connection.connect();
Reader in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
for ( int c = in.read(); c != -1; c = in.read() )
System.out.print((char)c);
}
catch(IOException e){
System.out.println(e);
}

How to read XML returned by HTTP POST request?

NOT a duplicate of my other question.
I am sending a POST request like this:
String urlParameters = "a=b&c=d";
String request = "http://www.example.com/";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("charset", "utf-8");
connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
connection.setUseCaches(false);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
connection.disconnect();
How can I read the xml response returned from a HTTP POST request? Particularly, I want to save the response file as a .xml file, and then read it. For my usual GET requests, I use this:
SAXBuilder builder = new SAXBuilder();
URL website = new URL(urlToParse);
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream("request.xml");
fos.getChannel().transferFrom(rbc, 0, 1 << 24);
fos.close();
// Do the work
Addendum: I'm using the following code and it works just fine. However, it neglects any spacing and new lines and treats the complete XML contents as a single line. How do I fix it?
InputStream is = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb1 = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
sb1.append(line);
}
FileOutputStream f = new FileOutputStream("request.xml");
f.write(sb1.toString().getBytes());
f.close();
br.close();

don't use Readers and readLine() with xml data. use InputStreams and byte[]s.

Thanks to Pangea, I modified his code and this now works:
TransformerFactory transFactory = TransformerFactory.newInstance();
Transformer t= transFactory.newTransformer();
t.setOutputProperty(OutputKeys.METHOD, "xml");
t.setOutputProperty(OutputKeys.INDENT,"yes");
Source input = new StreamSource(is);
Result output = new StreamResult(new FileOutputStream("request.xml"));
transFactory.newTransformer().transform(input, output);