add UnknownSync action

Author: jackie-coming

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/RemoteConfigRepository.java

@@ -268,7 +268,13 @@ private ApolloConfig loadApolloConfig() {
                   (previousConfig != null) ? previousConfig.getConfigurations() : null;
               result.setConfigurations(
                   mergeConfigurations(previousConfigurations, result.getConfigurationChanges()));
+            } else if (configSyncType == ConfigSyncType.UNKNOWN) {
+              String message = String.format(
+                  "Apollo Config Sync type invalid - configSyncType: %s",
+                  result.getConfigSyncType());
+              throw new ApolloConfigException(message, exception);
             }
+
           }
 
           logger.debug("Loaded config for {}: {}", m_namespace, result);

apollo-client/src/test/java/com/ctrip/framework/apollo/internals/RemoteConfigRepositoryTest.java

@@ -274,6 +274,24 @@ public void testMergeConfigurationWithChangesIsNULL() throws Exception {
     assertEquals(value2, result.get(key2));
   }
 
+  @Test(expected = ApolloConfigException.class)
+  public void testGetRemoteConfigWithUnknownSync() throws Exception {
+
+    ApolloConfig someApolloConfigWithUnknownSync = assembleApolloConfigWithUnknownSync(
+        new ArrayList<>());
+
+    when(someResponse.getStatusCode()).thenReturn(200);
+    when(someResponse.getBody()).thenReturn(someApolloConfigWithUnknownSync);
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+
+    //must stop the long polling before exception occurred
+    remoteConfigLongPollService.stopLongPollingRefresh();
+
+    remoteConfigRepository.getConfig();
+  }
+
   @Test
   public void testLoadConfigWithOrderedProperties() throws Exception {
     String someKey = "someKey";
@@ -504,6 +522,19 @@ private ApolloConfig assembleApolloConfigWithIncrementalSync(
     return apolloConfig;
   }
 
+  private ApolloConfig assembleApolloConfigWithUnknownSync(
+      List<ConfigurationChange> configurationChanges) {
+    String someAppId = "appId";
+    String someClusterName = "cluster";
+    String someReleaseKey = "1";
+    ApolloConfig apolloConfig =
+        new ApolloConfig(someAppId, someClusterName, someNamespace, someReleaseKey);
+
+    apolloConfig.setConfigSyncType(ConfigSyncType.UNKNOWN.getValue());
+    apolloConfig.setConfigurationChanges(configurationChanges);
+    return apolloConfig;
+  }
+
   public static class MockConfigUtil extends ConfigUtil {
 
     @Override

apollo-core/src/main/java/com/ctrip/framework/apollo/core/enums/ConfigSyncType.java

@@ -37,8 +37,6 @@ public enum ConfigSyncType {
    *
    * @param value the string that matches
    * @return the matching {@link ConfigSyncType}
-   * @throws IllegalArgumentException in case the <code>value</code> is empty or there is no
-   *                                  matching {@link ConfigSyncType}
    */
   public static ConfigSyncType fromString(String value) {
     if (StringUtils.isEmpty(value)) {