401:Authentication credentials were invalid - Invalid or expired token. code - 89 - twitter

Question

This is the code and I am recieving the error 401: Authentication Error
public class Server {
// initialize socket and input stream
private Socket socket = null;
private ServerSocket server = null;
private DataInputStream in = null;
public void tweet() throws TwitterException {
ConfigurationBuilder cb = new ConfigurationBuilder();
cb.setDaemonEnabled(true).setOAuthConsumerKey("......")
.setOAuthConsumerSecret("......")
.setOAuthAccessToken("......")
.setOAuthAccessTokenSecret(".....");
TwitterFactory tf = new TwitterFactory();
twitter4j.Twitter twitter = tf.getInstance();
List status = twitter.getHomeTimeline();
for (Status st : status) {
System.out.println(st.getUser().getName() + "---- Tweets----" + st.getText());
}
}
// constructor with port
public Server(int port) throws TwitterException {
// starts server and waits for a connection
try {
server = new ServerSocket(port);
System.out.println("Server started");
System.out.println("Waiting for a client ...");
socket = server.accept();
System.out.println("Client accepted");
// takes input from the client socket
in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
String line = "";
// reads message from client until "Over" is sent
while (!line.equals("Over")) {
try {
line = in.readUTF();
System.out.println(line);
if (line.equalsIgnoreCase("Data")) {
tweet();
}
} catch (IOException i) {
System.out.println(i);
}
}
System.out.println("Closing connection");
// close connection
socket.close();
in.close();
} catch (IOException i) {
System.out.println(i);
}
}
public static void main(String args[]) throws TwitterException {
Server server = new Server(5000);
}
}

Answer 1

Please make sure that the tokens are valid.
Then, you could try enabling system proxies like so:
System.setProperty("java.net.useSystemProxies", "true");