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POIOException not catching java.net.UnknownHostException:
 

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    <p>So I created a small method to send a request to a website, and I wanted to make sure it didn't crash. When I disconnect the internet and call the method, I get a <code>java.net.UnknownHostException:</code>, but I am not able to catch it. What am I doing wrong? </p> <p>The line that is giving issues atm is <code>HttpResponse response = httpclient.execute(httppost);</code></p> <p>I even handle the ClientProtocolException (subclass of IO) before the IO, so I could have both catch blocks. I've also tried adding <code>throws clauses</code> for the high level <code>Exception e</code>. Here is my code:</p> <pre><code>public String connect(String username, String password) { String answer = "Could not connect to server, please check your internet connect or try later."; try { DefaultHttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost(baseurl); // Request parameters and other properties. List&lt;NameValuePair&gt; params = new ArrayList&lt;NameValuePair&gt;(2); params.add(new BasicNameValuePair("usernameUS", username)); params.add(new BasicNameValuePair("passwordUS", password)); httppost.setEntity(new UrlEncodedFormEntity(params, "UTF-8")); // Execute and get the response. HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); if (entity != null) { answer = EntityUtils.toString(entity, charset); try { if (answer.equals("Authenticated")) { this.password = password; this.username = username; Authenticated = true; return answer; } else { return answer; } } finally { } } return "Could not connect to server, please try later."; } catch (ClientProtocolException ex) { Logger.getLogger(Connection.class.getName()).log(Level.SEVERE, null, ex); return answer; } catch (IOException ex) { Logger.getLogger(Connection.class.getName()).log(Level.SEVERE, null, ex); return answer; } } </code></pre> <p>And the exception:</p> <pre><code>java.net.UnknownHostException: www.example.com at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method) at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:866) at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1258) at java.net.InetAddress.getAllByName0(InetAddress.java:1211) at java.net.InetAddress.getAllByName(InetAddress.java:1127) at java.net.InetAddress.getAllByName(InetAddress.java:1063) at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45) at org.apache.http.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:278) at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:162) at org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:294) at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:640) at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:479) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784) at usclient.Connection.connect(Connection.java:65) </code></pre> <p>Working code:</p> <pre><code>public class Connection { private static Connection conn; String username, fileURL; String baseurl = "http://www.example.com"; String content, password = ""; String charset = "UTF-8"; HttpURLConnection request; URL url; OutputStreamWriter post; BufferedReader in; private Connection() { } public static Connection getInstance() { if(conn==null) { conn = new Connection(); } return conn; } public String connect(String username, String password){ String answer = "Could not connect to server, please check your internet connect or try later."; try { DefaultHttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost(baseurl); // Request parameters and other properties. List&lt;NameValuePair&gt; params = new ArrayList&lt;NameValuePair&gt;(2); params.add(new BasicNameValuePair("usernameUS", username)); params.add(new BasicNameValuePair("passwordUS", password)); httppost.setEntity(new UrlEncodedFormEntity(params, "UTF-8")); //Execute and get the response. HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); if (entity != null) { String[] data = EntityUtils.toString(entity, charset).split("\\n"); answer = data[0]; try { if(answer.contentEquals("Authenticated")) { this.password = password; this.username = username; if(data.length&lt;1) fileURL = data[1]; return data[0]; } else { return answer; } } finally { } } return "Could not connect to server, please try later."; } catch (ClientProtocolException ex) { Logger.getLogger(Connection.class.getName()).log(Level.SEVERE, "Exception caught:", ex); return empty; } catch (IOException ex) { Logger.getLogger(Connection.class.getName()).log(Level.SEVERE, "Exception caught:", ex); return empty; } } </code></pre>
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    1. COwhich line is throwing it?
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    2. COWill add on question too, sorry. HttpResponse response = httpclient.execute(httppost);
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    3. COAre you sure this stack trace isn't printed by your Logger.log() call in the catch block?
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