EWS: in direct EWS mode, try to use ResolveNames to get current user email address

git-svn-id: http://svn.code.sf.net/p/davmail/code/trunk@2212 3d1905a2-6b24-0410-a738-b14d5a86fcbd

src/java/davmail/exchange/ews/EwsExchangeSession.java

@@ -211,9 +211,15 @@ public class EwsExchangeSession extends ExchangeSession {
             } else {
                 // userName or domain\\username, rebuild email address
                 alias = getAliasFromLogin();
+
+                // try to get email address with ResolveNames
+                email = resolveEmailAddress(userName);
+                // failover, build from host name
+                if (email == null) {
                     email = getAliasFromLogin() + getEmailSuffixFromHostname();
                 }
             }
+        }
 
         currentMailboxPath = "/users/" + email.toLowerCase();
 
@@ -287,6 +293,29 @@ public class EwsExchangeSession extends ExchangeSession {
         LOGGER.debug("Current user email is " + email + ", alias is " + alias + " on " + serverVersion);
     }
 
+    public String resolveEmailAddress(String userName) {
+        String email = null;
+        String searchValue = userName;
+        int index = searchValue.indexOf('\\');
+        if (index >= 0) {
+            searchValue = searchValue.substring(index+1);
+        }
+        ResolveNamesMethod resolveNamesMethod = new ResolveNamesMethod(searchValue);
+        try {
+            // send a fake request to get server version
+            internalGetFolder("");
+            executeMethod(resolveNamesMethod);
+            List<EWSMethod.Item> responses = resolveNamesMethod.getResponseItems();
+            if (responses.size() == 1) {
+                email = responses.get(0).get("EmailAddress");
+            }
+
+        } catch (IOException e) {
+            // ignore
+        }
+        return email;
+    }
+
     protected static class AutoDiscoverMethod extends PostMethod {
         AutoDiscoverMethod(String autodiscoverHost, String userEmail) {
             super("https://" + autodiscoverHost + "/autodiscover/autodiscover.xml");