--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/core/src/main/java/com/redhat/thermostat/utils/username/UserNameLookupException.java	Thu May 23 18:36:15 2013 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2012, 2013 Red Hat, Inc.
+ *
+ * This file is part of Thermostat.
+ *
+ * Thermostat is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * Thermostat is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Thermostat; see the file COPYING.  If not see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Linking this code with other modules is making a combined work
+ * based on this code.  Thus, the terms and conditions of the GNU
+ * General Public License cover the whole combination.
+ *
+ * As a special exception, the copyright holders of this code give
+ * you permission to link this code with independent modules to
+ * produce an executable, regardless of the license terms of these
+ * independent modules, and to copy and distribute the resulting
+ * executable under terms of your choice, provided that you also
+ * meet, for each linked independent module, the terms and conditions
+ * of the license of that module.  An independent module is a module
+ * which is not derived from or based on this code.  If you modify
+ * this code, you may extend this exception to your version of the
+ * library, but you are not obligated to do so.  If you do not wish
+ * to do so, delete this exception statement from your version.
+ */
+
+package com.redhat.thermostat.utils.username;
+
+/**
+ * 
+ * Thrown on user name lookup error.
+ *
+ * @see UserNameUtil
+ */
+@SuppressWarnings("serial")
+public class UserNameLookupException extends Exception {
+
+    public UserNameLookupException(Throwable cause) {
+        super(cause);
+    }
+}

--- a/agent/core/src/main/java/com/redhat/thermostat/utils/username/UserNameUtil.java	Mon May 27 13:22:58 2013 -0400
+++ b/agent/core/src/main/java/com/redhat/thermostat/utils/username/UserNameUtil.java	Thu May 23 18:36:15 2013 +0200
@@ -36,17 +36,20 @@
 
 package com.redhat.thermostat.utils.username;
 
-
 /**
  * Utility to query the operating system for a user name.
  */
 public interface UserNameUtil {
-    
+
     /**
-     * Returns the user name corresponding to the provided UID.
-     * @param uid - the UID whose name to return
-     * @return the user name if found, or null otherwise
+     * Gets the user name corresponding to the provided UID.
+     * 
+     * @param uid
+     *            The UID whose name to return.
+     * @throws UserNameLookupException
+     *            If an error occurred during retrieval of the user name.
+     * @return The user name if found. null if no such UID exists.
      */
-    String getUserName(long uid);
+    String getUserName(long uid) throws UserNameLookupException;
 
 }

--- a/agent/core/src/main/java/com/redhat/thermostat/utils/username/internal/UserNameUtilImpl.java	Mon May 27 13:22:58 2013 -0400
+++ b/agent/core/src/main/java/com/redhat/thermostat/utils/username/internal/UserNameUtilImpl.java	Thu May 23 18:36:15 2013 +0200
@@ -37,14 +37,11 @@
 package com.redhat.thermostat.utils.username.internal;
 
 import java.io.IOException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
-import com.redhat.thermostat.common.utils.LoggingUtils;
+import com.redhat.thermostat.utils.username.UserNameLookupException;
 import com.redhat.thermostat.utils.username.UserNameUtil;
 
 public class UserNameUtilImpl implements UserNameUtil {
-    private static final Logger logger = LoggingUtils.getLogger(UserNameUtilImpl.class);
     
     static {
         /*
@@ -54,16 +51,21 @@
         System.loadLibrary("UserNameUtilWrapper");
     }
     
-    public String getUserName(long uid) {
-        String result = null;
+    public String getUserName(long uid) throws UserNameLookupException {
+        String username = null;
         if (uid >= 0) {
             try {
-                result = getUserName0(uid);
+                // getUserName0 may throw IOException. We catch it here and
+                // throw a more specific exception in order to avoid API 
+                // leakage. This exception is then dealt with in the caller of
+                // this method rather than here. This free's us from using the
+                // logger in a JNI class.
+                username = getUserName0(uid);
             } catch (IOException e) {
-                logger.log(Level.WARNING, "Unable to retrieve username for uid: " + uid, e);
+                throw new UserNameLookupException(e);
             }
         }
-        return result;
+        return username;
     }
     
     private native String getUserName0(long uid) throws IOException;

--- a/system-backend/src/main/java/com/redhat/thermostat/backend/system/ProcessUserInfoBuilder.java	Mon May 27 13:22:58 2013 -0400
+++ b/system-backend/src/main/java/com/redhat/thermostat/backend/system/ProcessUserInfoBuilder.java	Thu May 23 18:36:15 2013 +0200
@@ -44,6 +44,7 @@
 
 import com.redhat.thermostat.common.utils.LoggingUtils;
 import com.redhat.thermostat.utils.ProcDataSource;
+import com.redhat.thermostat.utils.username.UserNameLookupException;
 import com.redhat.thermostat.utils.username.UserNameUtil;
 
 class ProcessUserInfoBuilder {
@@ -88,7 +89,12 @@
         try {
             Reader reader = source.getStatusReader(pid);
             long uid = getUidFromProcfs(new BufferedReader(reader));
-            String name = userNameUtil.getUserName(uid);
+            String name = null;
+            try {
+                name = userNameUtil.getUserName(uid);
+            } catch (UserNameLookupException e) {
+                logger.log(Level.WARNING, "Unable to retrieve username for uid: " + uid, e);
+            }
             info = new ProcessUserInfo(uid, name);
         } catch (IOException e) {
             logger.log(Level.WARNING, "Unable to read user info for " + pid, e);

--- a/system-backend/src/test/java/com/redhat/thermostat/backend/system/ProcessUserInfoBuilderTest.java	Mon May 27 13:22:58 2013 -0400
+++ b/system-backend/src/test/java/com/redhat/thermostat/backend/system/ProcessUserInfoBuilderTest.java	Thu May 23 18:36:15 2013 +0200
@@ -49,12 +49,13 @@
 import com.redhat.thermostat.backend.system.ProcessUserInfoBuilder.ProcessUserInfo;
 import com.redhat.thermostat.common.tools.ApplicationException;
 import com.redhat.thermostat.utils.ProcDataSource;
+import com.redhat.thermostat.utils.username.UserNameLookupException;
 import com.redhat.thermostat.utils.username.UserNameUtil;
 
 public class ProcessUserInfoBuilderTest {
     
     @Test
-    public void testBuild() throws IOException, ApplicationException {
+    public void testBuild() throws UserNameLookupException, IOException, ApplicationException {
         StringReader reader = new StringReader("Uid:   2000  2000  2000  2000");
         ProcDataSource source = mock(ProcDataSource.class);
         UserNameUtil util = mock(UserNameUtil.class);
@@ -81,7 +82,7 @@
     }
     
     @Test
-    public void testBuildErrorUsername() throws IOException, ApplicationException {
+    public void testBuildErrorUsername() throws IOException, UserNameLookupException, ApplicationException {
         StringReader reader = new StringReader("Uid:   2000  2000  2000  2000");
         ProcDataSource source = mock(ProcDataSource.class);
         UserNameUtil util = mock(UserNameUtil.class);