Twitter4j, Unknown Host exception

Question

I try to operate the basic functions of twitter4j to train me on this library. My first test is to retrieve my timeline is one of the first tutorials on the site twitter4j.

Here's my code to retrieve my timeline :

String accessToken = "***";
String accessSecret = "***";
String consumerKey = "***";
String consumerSecret = "***";

ConfigurationBuilder cb = new ConfigurationBuilder();
cb.setDebugEnabled(true)
    .setOAuthConsumerKey(consumerKey)
    .setOAuthConsumerSecret(consumerSecret)
    .setOAuthAccessToken(accessToken)
    .setOAuthAccessTokenSecret(accessSecret);

TwitterFactory tf = new TwitterFactory(cb.build());
Twitter twitter = tf.getInstance();

List<Status> statuses = twitter.getHomeTimeline();

System.out.println("Showing home timeline.");

for (Status status : statuses) {

    System.out.println(status.getUser().getName() + ":" +
    status.getText());

}

But with this simple code, I have the following error :

Exception in thread "main" api.twitter.com
Relevant discussions can be found on the Internet at:
    http://www.google.co.jp/search?q=e5488403 or
    http://www.google.co.jp/search?q=09b41b1e
TwitterException{exceptionCode=[e5488403-09b41b1e 6ece33f2-2ccf4468], statusCode=-1, message=null, code=-1, retryAfter=-1, rateLimitStatus=null, version=3.0.3}
    at twitter4j.internal.http.HttpClientImpl.request(HttpClientImpl.java:192)
    at twitter4j.internal.http.HttpClientWrapper.request(HttpClientWrapper.java:61)
    at twitter4j.internal.http.HttpClientWrapper.get(HttpClientWrapper.java:81)
    at twitter4j.TwitterImpl.get(TwitterImpl.java:1835)
    at twitter4j.TwitterImpl.getHomeTimeline(TwitterImpl.java:117)
    at Test.main(Test.java:32)
Caused by: java.net.UnknownHostException: api.twitter.com
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at sun.net.NetworkClient.doConnect(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.<init>(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at twitter4j.internal.http.HttpResponseImpl.<init>(HttpResponseImpl.java:34)
    at twitter4j.internal.http.HttpClientImpl.request(HttpClientImpl.java:156)
    ... 5 more

Where is the problem ?

Answer 1

Finally, I got my problem, the code was perfect but i have a proxy. So I fixed it :

    ConfigurationBuilder cb = new ConfigurationBuilder();
    cb.setDebugEnabled(true)
            .setOAuthConsumerKey(consumerKey)
            .setOAuthConsumerSecret(consumerSecret)
            .setOAuthAccessToken(accessToken)
            .setOAuthAccessTokenSecret(accessSecret)

            // PROXY
            .setHttpProxyHost(proxyHost)
            .setHttpProxyPort(proxyPort)
            ;