Fix configuration to create new instance on load

Author: jianghaolu

core/azure-core/src/main/java/com/microsoft/windowsazure/Configuration.java

@@ -56,11 +56,6 @@ public class Configuration {
      * of the proxy to use
      */
     public static final String PROPERTY_HTTP_PROXY_PORT = "http.proxyPort";
-    
-    /**
-     * The configuration instance.
-     */
-    private static Configuration instance;
 
     /**
      * The configuration properties.
@@ -85,21 +80,14 @@ public Configuration(Builder builder) {
     }
 
     public static Configuration getInstance() {
-        if (instance == null) {
-            try {
-                instance = Configuration.load();
-            } catch (IOException e) {
-                log.error(
-                    "Unable to load META-INF/com.microsoft.windowsazure.properties",
-                    e);
-                instance = new Configuration();
-            }
+        try {
+            return Configuration.load();
+        } catch (IOException e) {
+            log.error(
+                "Unable to load META-INF/com.microsoft.windowsazure.properties",
+                e);
+            return new Configuration();
         }
-        return instance;
-    }
-
-    public static void setInstance(final Configuration configuration) {
-        Configuration.instance = configuration;
     }
 
     public static Configuration load() throws IOException {

services/azure-servicebus/src/test/java/com/microsoft/windowsazure/services/servicebus/ServiceBusIntegrationTest.java

@@ -95,8 +95,7 @@ public Client alter(String profile, Client instance,
                 });
 
         // applied as default configuration
-        Configuration.setInstance(config);
-        service = ServiceBusService.create();
+        service = ServiceBusService.create(config);
     }
 
     @Test