Move DNS resolving into connect()

It was misplaced in ConnectionConfiguration anyways, as the sole
instantiation of a ConnectionConfiguration should not cause any network
I/O.

core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java

@@ -102,8 +102,6 @@ public class ConnectionConfiguration implements Cloneable {
      * @param serviceName the name of the service provided by an XMPP server.
      */
     public ConnectionConfiguration(String serviceName) {
-        // Perform DNS lookup to get host and port to use
-        hostAddresses = DNSUtil.resolveXMPPDomain(serviceName);
         init(serviceName, ProxyInfo.forDefaultProxy());
     }
 
@@ -117,8 +115,6 @@ public class ConnectionConfiguration implements Cloneable {
      * @param proxy the proxy through which XMPP is to be connected
      */
     public ConnectionConfiguration(String serviceName,ProxyInfo proxy) {
-        // Perform DNS lookup to get host and port to use
-        hostAddresses = DNSUtil.resolveXMPPDomain(serviceName);
         init(serviceName, proxy);
     }
 
@@ -203,7 +199,7 @@ public class ConnectionConfiguration implements Cloneable {
      *
      * @param serviceName the XMPP domain of the target server.
      */
-    public void setServiceName(String serviceName) {
+    void setServiceName(String serviceName) {
         this.serviceName = serviceName;
     }
 
@@ -569,14 +565,17 @@ public class ConnectionConfiguration implements Cloneable {
         this.resource = resource;
     }
 
+    void maybeResolveDns() throws Exception {
+        // Abort if we did already resolve the hosts successfully
+        if (hostAddresses != null)
+            return;
+        hostAddresses = DNSUtil.resolveXMPPDomain(serviceName);
+    }
+
     private void initHostAddresses(String host, int port) {
         hostAddresses = new ArrayList<HostAddress>(1);
         HostAddress hostAddress;
-        try {
         hostAddress = new HostAddress(host, port);
-        } catch (Exception e) {
-            throw new IllegalStateException(e);
-        }
         hostAddresses.add(hostAddress);
     }
 }

core/src/main/java/org/jivesoftware/smack/util/DNSUtil.java

@@ -77,8 +77,9 @@ public class DNSUtil {
      * @param domain the domain.
      * @return List of HostAddress, which encompasses the hostname and port that the
      *      XMPP server can be reached at for the specified domain.
+     * @throws Exception 
      */
-    public static List<HostAddress> resolveXMPPDomain(final String domain) {
+    public static List<HostAddress> resolveXMPPDomain(final String domain) throws Exception {
         if (dnsResolver == null) {
             List<HostAddress> addresses = new ArrayList<HostAddress>(1);
             addresses.add(new HostAddress(domain, 5222));
@@ -103,8 +104,9 @@ public class DNSUtil {
      * @param domain the domain.
      * @return List of HostAddress, which encompasses the hostname and port that the
      *      XMPP server can be reached at for the specified domain.
+     * @throws Exception 
      */
-    public static List<HostAddress> resolveXMPPServerDomain(final String domain) {
+    public static List<HostAddress> resolveXMPPServerDomain(final String domain) throws Exception {
         if (dnsResolver == null) {
             List<HostAddress> addresses = new ArrayList<HostAddress>(1);
             addresses.add(new HostAddress(domain, 5269));
@@ -113,7 +115,7 @@ public class DNSUtil {
         return resolveDomain(domain, 's');
     }
 
-    private static List<HostAddress> resolveDomain(String domain, char keyPrefix) {
+    private static List<HostAddress> resolveDomain(String domain, char keyPrefix) throws Exception {
         // Prefix the key with 's' to distinguish him from the client domain lookups
         String key = keyPrefix + domain;
         // Return item from cache if it exists.

core/src/main/java/org/jivesoftware/smack/util/dns/DNSResolver.java

@@ -29,6 +29,6 @@ public interface DNSResolver {
      * @param name The symbolic name of the service.
      * @return The list of SRV records mapped to the service name.
      */
-    List<SRVRecord> lookupSRVRecords(String name);
+    List<SRVRecord> lookupSRVRecords(String name) throws Exception;
 
 }

core/src/main/java/org/jivesoftware/smack/util/dns/HostAddress.java

@@ -51,7 +51,7 @@ public class HostAddress {
         this(fqdn);
         if (port < 0 || port > 65535)
             throw new IllegalArgumentException(
-                    "DNS SRV records weight must be a 16-bit unsiged integer (i.e. between 0-65535. Port was: " + port);
+                    "Port must be a 16-bit unsiged integer (i.e. between 0-65535. Port was: " + port);
 
         this.port = port;
     }

resolver-dnsjava/src/main/java/org/jivesoftware/smack/util/dns/DNSJavaResolver.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2013 Florian Schmaus
+ * Copyright 2013-2014 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.util.List;
 
 import org.xbill.DNS.Lookup;
 import org.xbill.DNS.Record;
+import org.xbill.DNS.TextParseException;
 import org.xbill.DNS.Type;
 
 /**
@@ -39,10 +40,9 @@ public class DNSJavaResolver implements DNSResolver {
     }
 
     @Override
-    public List<SRVRecord> lookupSRVRecords(String name) {
+    public List<SRVRecord> lookupSRVRecords(String name) throws TextParseException {
         List<SRVRecord> res = new ArrayList<SRVRecord>();
 
-        try {
         Lookup lookup = new Lookup(name, Type.SRV);
         Record recs[] = lookup.run();
         if (recs == null)
@@ -56,18 +56,11 @@ public class DNSJavaResolver implements DNSResolver {
                 int priority = srvRecord.getPriority();
                 int weight = srvRecord.getWeight();
 
-                    SRVRecord r;
+                SRVRecord r = new SRVRecord(host, port, priority, weight);
-                    try {
-                        r = new SRVRecord(host, port, priority, weight);
-                    } catch (Exception e) {
-                        continue;
-                    }
                 res.add(r);
             }
         }
 
-        } catch (Exception e) {
-        }
         return res;
     }
 }

resolver-javax/src/main/java/org/jivesoftware/smack/util/dns/JavaxResolver.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2013 Florian Schmaus
+ * Copyright 2013-2014 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.util.Hashtable;
 import java.util.List;
 
 import javax.naming.NamingEnumeration;
+import javax.naming.NamingException;
 import javax.naming.directory.Attribute;
 import javax.naming.directory.Attributes;
 import javax.naming.directory.DirContext;
@@ -68,10 +69,9 @@ public class JavaxResolver implements DNSResolver {
     }
 
     @Override
-    public List<SRVRecord> lookupSRVRecords(String name) {
+    public List<SRVRecord> lookupSRVRecords(String name) throws NamingException {
         List<SRVRecord> res = new ArrayList<SRVRecord>();
 
-        try {
         Attributes dnsLookup = dirContext.getAttributes(name, new String[] { "SRV" });
         Attribute srvAttribute = dnsLookup.get("SRV");
         @SuppressWarnings("unchecked")
@@ -84,17 +84,9 @@ public class JavaxResolver implements DNSResolver {
             int weight = Integer.parseInt(srvRecordEntries[srvRecordEntries.length - 3]);
             String host = srvRecordEntries[srvRecordEntries.length - 1];
 
-                SRVRecord srvRecord;
+            SRVRecord srvRecord = new SRVRecord(host, port, priority, weight);
-                try {
-                    srvRecord = new SRVRecord(host, port, priority, weight);
-                } catch (Exception e) {
-                    continue;
-                }
             res.add(srvRecord);
         }
-        } catch (Exception e) {
-            
-        }
         return res;
     }
 }

tcp/src/main/java/org/jivesoftware/smack/TCPConnection.java

@@ -420,6 +420,12 @@ public class TCPConnection extends XMPPConnection {
 
     private void connectUsingConfiguration(ConnectionConfiguration config) throws SmackException, IOException {
         Exception exception = null;
+        try {
+            config.maybeResolveDns();
+        }
+        catch (Exception e) {
+            throw new SmackException(e);
+        }
         Iterator<HostAddress> it = config.getHostAddresses().iterator();
         List<HostAddress> failedAddresses = new LinkedList<HostAddress>();
         while (it.hasNext()) {