java - Twitter call request -

i have problem source code twitter request. response returned twitter blank string. can advice can problem?

i have registered app on dev.twitter.com. called reach count.

this code brought tutorial: http://www.coderslexicon.com/demo-of-twitter-application-only-oauth-authentication-using-java/

package count_reach_twitter;  //import com.sun.org.apache.xerces.internal.impl.dv.util.base64; import java.io.bufferedreader; import java.io.bufferedwriter; import java.io.ioexception; import java.io.inputstreamreader; import java.io.outputstreamwriter; import java.io.unsupportedencodingexception; import java.net.malformedurlexception; import java.net.url; import java.net.urlencoder; import javax.net.ssl.httpsurlconnection; import org.apache.commons.codec.binary.base64; import org.json.jsonarray; import org.json.jsonobject;  /**  *  * @author martin  */ public class twittercall {      // encodes consumer key , secret create basic authorization key private static string encodekeys(string consumerkey, string consumersecret) {     try {         string encodedconsumerkey = urlencoder.encode(consumerkey, "utf-8");         string encodedconsumersecret = urlencoder.encode(consumersecret, "utf-8");          string fullkey = encodedconsumerkey + ":" + encodedconsumersecret;         byte[] encodedbytes = base64.encodebase64(fullkey.getbytes());          return new string(encodedbytes);       }     catch (unsupportedencodingexception e) {         return new string();     } }  // writes request connection private static boolean writerequest(httpsurlconnection connection, string textbody) {     try {         bufferedwriter wr = new bufferedwriter(new outputstreamwriter(connection.getoutputstream()));         wr.write(textbody);         wr.flush();         wr.close();          return true;     }     catch (ioexception e) { return false; } }   // reads response given connection , returns string. private static string readresponse(httpsurlconnection connection) {     try {         stringbuilder str = new stringbuilder();          bufferedreader br = new bufferedreader(new inputstreamreader(connection.getinputstream()));         string line = "";         while((line = br.readline()) != null) {             str.append(line + system.getproperty("line.separator"));         }         return str.tostring();     }     catch (ioexception e) { return new string(); } }  // constructs request requesting bearer token , returns token string private static string requestbearertoken(string endpointurl) throws ioexception {     httpsurlconnection connection = null;     string encodedcredentials = encodekeys("my customer key","my customer secret key");      try {         url url = new url(endpointurl);          connection = (httpsurlconnection) url.openconnection();                    connection.setdooutput(true);         connection.setdoinput(true);          connection.setrequestmethod("post");          connection.setrequestproperty("host", "api.twitter.com");         connection.setrequestproperty("user-agent", "reach count");         connection.setrequestproperty("authorization", "basic " + encodedcredentials);         connection.setrequestproperty("content-type", "application/x-www-form-urlencoded;charset=utf-8");          connection.setrequestproperty("content-length", "29");         connection.setusecaches(false);          //writerequest(connection, "grant_type=client_credentials");          // parse json response json mapped object fetch fields from.                 system.out.println("response: " + readresponse(connection));                 system.out.println("end");         jsonobject obj = new jsonobject(readresponse(connection)); //(jsonobject)jsonvalue.parse(readresponse(connection));                 //obj.          if (obj != null) {             string tokentype = (string)obj.get("token_type");             string token = (string)obj.get("access_token");              return ((tokentype.equals("bearer")) && (token != null)) ? token : "";         }         return new string();     }     catch (malformedurlexception e) {         throw new ioexception("invalid endpoint url specified.", e);     }     {         if (connection != null) {             connection.disconnect();         }     } }  // fetches first tweet given user's timeline public static string fetchtimelinetweet(string endpointurl) throws ioexception {     httpsurlconnection connection = null;      try {         url url = new url(endpointurl);          connection = (httpsurlconnection) url.openconnection();                    connection.setdooutput(true);         connection.setdoinput(true);          connection.setrequestmethod("get");          connection.setrequestproperty("host", "api.twitter.com");         connection.setrequestproperty("user-agent", "reach count");         connection.setrequestproperty("authorization", "bearer " + requestbearertoken("https://api.twitter.com/oauth2/token"));         connection.setusecaches(false);           // parse json response json mapped object fetch fields from.         jsonarray obj = new jsonarray(readresponse(connection));//(jsonarray)jsonvalue.parse(readresponse(connection));          if (obj != null) {             string tweet = ((jsonobject)obj.get(0)).get("text").tostring();              return (tweet != null) ? tweet : "";         }         return new string();     }     catch (malformedurlexception e) {         throw new ioexception("invalid endpoint url specified.", e);     }     {         if (connection != null) {             connection.disconnect();         }     } }   } 

main function calling next method:

system.out.println(twittercall.fetchtimelinetweet("https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=dj_fedy&count=50")); 

thank you

i'm not sure why code gets 403 twitter. can think of 2 things:

1. according bottom of application-only authentication doc, 403 response given when use bearer token on endpoint doesn't support application-only auth. cannot find whether get on statuses/user_timeline allowed application-only auth.
2. according get statuses/user_timeline doc, can request tweets protected user when authenticated user either "owns" timeline or approved follower of owner. i'm not sure whether case you.