SOLR-8995: Use lambda to simplify CollectionsHandler

solr/core/src/java/org/apache/solr/handler/admin/CollectionsHandler.java

@@ -37,7 +37,6 @@ import org.apache.commons.lang.StringUtils;
 import org.apache.solr.client.solrj.SolrResponse;
 import org.apache.solr.client.solrj.impl.HttpSolrClient;
 import org.apache.solr.client.solrj.impl.HttpSolrClient.Builder;
-import org.apache.solr.client.solrj.request.CoreAdminRequest;
 import org.apache.solr.client.solrj.request.CoreAdminRequest.RequestSyncShard;
 import org.apache.solr.client.solrj.response.RequestStatusState;
 import org.apache.solr.client.solrj.util.SolrIdentifierValidator;
@@ -204,7 +203,7 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       log.info("Invoked Collection Action :{} with params {} and sendToOCPQueue={}", action.toLower(), req.getParamString(), operation.sendToOCPQueue);
 
       SolrResponse response = null;
-      Map<String, Object> props = operation.call(req, rsp, this);
+      Map<String, Object> props = operation.execute(req, rsp, this);
       String asyncId = req.getParams().get(ASYNC);
       if (props != null) {
         if (asyncId != null) {
@@ -335,7 +334,34 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
 
   public static final String SYSTEM_COLL = ".system";
 
-  enum CollectionOperation {
+  private static void createSysConfigSet(CoreContainer coreContainer) throws KeeperException, InterruptedException {
+    SolrZkClient zk = coreContainer.getZkController().getZkStateReader().getZkClient();
+    ZkCmdExecutor cmdExecutor = new ZkCmdExecutor(zk.getZkClientTimeout());
+    cmdExecutor.ensureExists(ZkStateReader.CONFIGS_ZKNODE, zk);
+    cmdExecutor.ensureExists(ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL, zk);
+
+    try {
+      String path = ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL + "/schema.xml";
+      byte[] data = IOUtils.toByteArray(Thread.currentThread().getContextClassLoader().getResourceAsStream("SystemCollectionSchema.xml"));
+      cmdExecutor.ensureExists(path, data, CreateMode.PERSISTENT, zk);
+      path = ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL + "/solrconfig.xml";
+      data = IOUtils.toByteArray(Thread.currentThread().getContextClassLoader().getResourceAsStream("SystemCollectionSolrConfig.xml"));
+      cmdExecutor.ensureExists(path, data, CreateMode.PERSISTENT, zk);
+    } catch (IOException e) {
+      throw new SolrException(ErrorCode.SERVER_ERROR, e);
+    }
+
+
+  }
+
+  private static void addStatusToResponse(NamedList<Object> results, RequestStatusState state, String msg) {
+    SimpleOrderedMap<String> status = new SimpleOrderedMap<>();
+    status.add("state", state.getKey());
+    status.add("msg", msg);
+    results.add("status", status);
+  }
+
+  enum CollectionOperation implements CollectionOp {
     /**
      * very simple currently, you can pass a template collection, and the new collection is created on
      * every node the template collection is on
@@ -343,10 +369,7 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
      * we might also want to think about error handling (add the request to a zk queue and involve overseer?)
      * as well as specific replicas= options
      */
-    CREATE_OP(CREATE) {
+    CREATE_OP(CREATE, (req, rsp, h) -> {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h)
-          throws KeeperException, InterruptedException {
       Map<String, Object> props = req.getParams().required().getAll(null, NAME);
       props.put("fromApi", "true");
       req.getParams().getAll(props,
@@ -367,7 +390,7 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       addMapObject(props, RULE);
       addMapObject(props, SNITCH);
       verifyRuleParams(h.coreContainer, props);
-        final String collectionName = SolrIdentifierValidator.validateCollectionName((String)props.get(NAME));
+      final String collectionName = SolrIdentifierValidator.validateCollectionName((String) props.get(NAME));
       final String shardsParam = (String) props.get(SHARDS_PROP);
       if (StringUtils.isNotEmpty(shardsParam)) {
         verifyShardsParam(shardsParam);
@@ -382,47 +405,12 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       copyPropertiesWithPrefix(req.getParams(), props, COLL_PROP_PREFIX);
       return copyPropertiesWithPrefix(req.getParams(), props, "router.");
 
-      }
+    }),
+    DELETE_OP(DELETE, (req, rsp, h) -> req.getParams().required().getAll(null, NAME)),
 
-      private void createSysConfigSet(CoreContainer coreContainer) throws KeeperException, InterruptedException {
+    RELOAD_OP(RELOAD, (req, rsp, h) -> req.getParams().required().getAll(null, NAME)),
-        SolrZkClient zk = coreContainer.getZkController().getZkStateReader().getZkClient();
-        ZkCmdExecutor cmdExecutor = new ZkCmdExecutor(zk.getZkClientTimeout());
-        cmdExecutor.ensureExists(ZkStateReader.CONFIGS_ZKNODE, zk);
-        cmdExecutor.ensureExists(ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL, zk);
 
-        try {
+    SYNCSHARD_OP(SYNCSHARD, (req, rsp, h) -> {
-          String path = ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL + "/schema.xml";
-          byte[] data = IOUtils.toByteArray(Thread.currentThread().getContextClassLoader().getResourceAsStream("SystemCollectionSchema.xml"));
-          cmdExecutor.ensureExists(path, data, CreateMode.PERSISTENT, zk);
-          path = ZkStateReader.CONFIGS_ZKNODE + "/" + SYSTEM_COLL + "/solrconfig.xml";
-          data = IOUtils.toByteArray(Thread.currentThread().getContextClassLoader().getResourceAsStream("SystemCollectionSolrConfig.xml"));
-          cmdExecutor.ensureExists(path, data, CreateMode.PERSISTENT, zk);
-        } catch (IOException e) {
-          throw new SolrException(ErrorCode.SERVER_ERROR, e);
-
-        }
-
-
-      }
-    },
-    DELETE_OP(DELETE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws Exception {
-        return req.getParams().required().getAll(null, NAME);
-      }
-    },
-    RELOAD_OP(RELOAD) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws Exception {
-        return req.getParams().required().getAll(null, NAME);
-      }
-    },
-    SYNCSHARD_OP(SYNCSHARD) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h)
-          throws Exception {
       String collection = req.getParams().required().get("collection");
       String shard = req.getParams().required().get("shard");
 
@@ -435,36 +423,20 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       try (HttpSolrClient client = new Builder(nodeProps.getBaseUrl()).build()) {
         client.setConnectionTimeout(15000);
         client.setSoTimeout(60000);
-          RequestSyncShard reqSyncShard = new CoreAdminRequest.RequestSyncShard();
+        RequestSyncShard reqSyncShard = new RequestSyncShard();
         reqSyncShard.setCollection(collection);
         reqSyncShard.setShard(shard);
         reqSyncShard.setCoreName(nodeProps.getCoreName());
         client.request(reqSyncShard);
       }
       return null;
-      }
+    }),
-
+    CREATEALIAS_OP(CREATEALIAS, (req, rsp, h) -> {
-    },
-    CREATEALIAS_OP(CREATEALIAS) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws Exception {
       final String aliasName = SolrIdentifierValidator.validateAliasName(req.getParams().get(NAME));
       return req.getParams().required().getAll(null, NAME, "collections");
-      }
+    }),
-    },
+    DELETEALIAS_OP(DELETEALIAS, (req, rsp, h) -> req.getParams().required().getAll(null, NAME)),
-    DELETEALIAS_OP(DELETEALIAS) {
+    SPLITSHARD_OP(SPLITSHARD, DEFAULT_COLLECTION_OP_TIMEOUT * 5, true, (req, rsp, h) -> {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws Exception {
-        return req.getParams().required().getAll(null, NAME);
-      }
-
-    },
-    SPLITSHARD_OP(SPLITSHARD, DEFAULT_COLLECTION_OP_TIMEOUT * 5, true) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h)
-          throws Exception {
       String name = req.getParams().required().get(COLLECTION_PROP);
       // TODO : add support for multiple shards
       String shard = req.getParams().get(SHARD_ID_PROP);
@@ -489,11 +461,8 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
           "split.key",
           CoreAdminParams.RANGES);
       return copyPropertiesWithPrefix(req.getParams(), map, COLL_PROP_PREFIX);
-      }
+    }),
-    },
+    DELETESHARD_OP(DELETESHARD, (req, rsp, h) -> {
-    DELETESHARD_OP(DELETESHARD) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           SHARD_ID_PROP);
@@ -502,22 +471,16 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
           DELETE_DATA_DIR,
           DELETE_INSTANCE_DIR);
       return map;
-      }
+    }),
-    },
+    FORCELEADER_OP(FORCELEADER, (req, rsp, h) -> {
-    FORCELEADER_OP(FORCELEADER) {
+      forceLeaderElection(req, h);
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
-        forceLeaderElection(req, handler);
       return null;
-      }
+    }),
-    },
+    CREATESHARD_OP(CREATESHARD, (req, rsp, h) -> {
-    CREATESHARD_OP(CREATESHARD) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           SHARD_ID_PROP);
-        ClusterState clusterState = handler.coreContainer.getZkController().getClusterState();
+      ClusterState clusterState = h.coreContainer.getZkController().getClusterState();
       final String newShardName = SolrIdentifierValidator.validateShardName(req.getParams().get(SHARD_ID_PROP));
       if (!ImplicitDocRouter.NAME.equals(((Map) clusterState.getCollection(req.getParams().get(COLLECTION_PROP)).get(DOC_ROUTER)).get(NAME)))
         throw new SolrException(ErrorCode.BAD_REQUEST, "shards can be added only to 'implicit' collections");
@@ -525,11 +488,8 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
           REPLICATION_FACTOR,
           CREATE_NODE_SET);
       return copyPropertiesWithPrefix(req.getParams(), map, COLL_PROP_PREFIX);
-      }
+    }),
-    },
+    DELETEREPLICA_OP(DELETEREPLICA, (req, rsp, h) -> {
-    DELETEREPLICA_OP(DELETEREPLICA) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           SHARD_ID_PROP,
@@ -541,52 +501,36 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
           DELETE_INSTANCE_DIR);
 
       return req.getParams().getAll(map, ONLY_IF_DOWN);
-      }
+    }),
-    },
+    MIGRATE_OP(MIGRATE, (req, rsp, h) -> {
-    MIGRATE_OP(MIGRATE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null, COLLECTION_PROP, "split.key", "target.collection");
       return req.getParams().getAll(map, "forward.timeout");
-      }
+    }),
-    },
+    ADDROLE_OP(ADDROLE, (req, rsp, h) -> {
-    ADDROLE_OP(ADDROLE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null, "role", "node");
       if (!KNOWN_ROLES.contains(map.get("role")))
         throw new SolrException(ErrorCode.BAD_REQUEST, "Unknown role. Supported roles are ," + KNOWN_ROLES);
       return map;
-      }
+    }),
-    },
+    REMOVEROLE_OP(REMOVEROLE, (req, rsp, h) -> {
-    REMOVEROLE_OP(REMOVEROLE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null, "role", "node");
       if (!KNOWN_ROLES.contains(map.get("role")))
         throw new SolrException(ErrorCode.BAD_REQUEST, "Unknown role. Supported roles are ," + KNOWN_ROLES);
       return map;
-      }
+    }),
-    },
+    CLUSTERPROP_OP(CLUSTERPROP, (req, rsp, h) -> {
-    CLUSTERPROP_OP(CLUSTERPROP) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       String name = req.getParams().required().get(NAME);
       String val = req.getParams().get(VALUE_LONG);
       ClusterProperties cp = new ClusterProperties(h.coreContainer.getZkController().getZkClient());
       cp.setClusterProperty(name, val);
       return null;
-      }
+    }),
-    },
+    REQUESTSTATUS_OP(REQUESTSTATUS, (req, rsp, h) -> {
-    REQUESTSTATUS_OP(REQUESTSTATUS) {
-      @SuppressWarnings("unchecked")
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       req.getParams().required().check(REQUESTID);
 
-        final CoreContainer coreContainer = h.coreContainer;
+      final CoreContainer coreContainer1 = h.coreContainer;
       final String requestId = req.getParams().get(REQUESTID);
-        final ZkController zkController = coreContainer.getZkController();
+      final ZkController zkController = coreContainer1.getZkController();
 
       final NamedList<Object> results = new NamedList<>();
       if (zkController.getOverseerCompletedMap().contains(requestId)) {
@@ -608,19 +552,11 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       final SolrResponse response = new OverseerSolrResponse(results);
       rsp.getValues().addAll(response.getResponse());
       return null;
-      }
+    }),
-
+    DELETESTATUS_OP(DELETESTATUS, new CollectionOp() {
-      private void addStatusToResponse(NamedList<Object> results, RequestStatusState state, String msg) {
-        SimpleOrderedMap<String> status = new SimpleOrderedMap<>();
-        status.add("state", state.getKey());
-        status.add("msg", msg);
-        results.add("status", status);
-      }
-    },
-    DELETESTATUS_OP(DELETESTATUS) {
       @SuppressWarnings("unchecked")
       @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
+      public Map<String, Object> execute(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
         final CoreContainer coreContainer = h.coreContainer;
         final String requestId = req.getParams().get(REQUESTID);
         final ZkController zkController = coreContainer.getZkController();
@@ -652,11 +588,8 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
         }
         return null;
       }
-    },
+    }),
-    ADDREPLICA_OP(ADDREPLICA) {
+    ADDREPLICA_OP(ADDREPLICA, (req, rsp, h) -> {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h)
-          throws Exception {
       Map<String, Object> props = req.getParams().getAll(null,
           COLLECTION_PROP,
           "node",
@@ -666,51 +599,36 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
           INSTANCE_DIR,
           DATA_DIR);
       return copyPropertiesWithPrefix(req.getParams(), props, COLL_PROP_PREFIX);
-      }
+    }),
-    },
+    OVERSEERSTATUS_OP(OVERSEERSTATUS, (req, rsp, h) -> (Map) new LinkedHashMap<>()),
-    OVERSEERSTATUS_OP(OVERSEERSTATUS) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
-        return new LinkedHashMap<>();
-      }
-    },
 
     /**
      * Handle list collection request.
      * Do list collection request to zk host
      */
-    LIST_OP(LIST) {
+    LIST_OP(LIST, (req, rsp, h) -> {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler) throws Exception {
       NamedList<Object> results = new NamedList<>();
-        Map<String, DocCollection> collections = handler.coreContainer.getZkController().getZkStateReader().getClusterState().getCollectionsMap();
+      Map<String, DocCollection> collections = h.coreContainer.getZkController().getZkStateReader().getClusterState().getCollectionsMap();
       List<String> collectionList = new ArrayList<>(collections.keySet());
       results.add("collections", collectionList);
       SolrResponse response = new OverseerSolrResponse(results);
       rsp.getValues().addAll(response.getResponse());
       return null;
-      }
+    }),
-    },
     /**
      * Handle cluster status request.
      * Can return status per specific collection/shard or per all collections.
      */
-    CLUSTERSTATUS_OP(CLUSTERSTATUS) {
+    CLUSTERSTATUS_OP(CLUSTERSTATUS, (req, rsp, h) -> {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws KeeperException, InterruptedException {
       Map<String, Object> all = req.getParams().getAll(null,
           COLLECTION_PROP,
           SHARD_ID_PROP,
           _ROUTE_);
-        new ClusterStatus(handler.coreContainer.getZkController().getZkStateReader(),
+      new ClusterStatus(h.coreContainer.getZkController().getZkStateReader(),
           new ZkNodeProps(all)).getClusterStatus(rsp.getValues());
       return null;
-      }
+    }),
-    },
+    ADDREPLICAPROP_OP(ADDREPLICAPROP, (req, rsp, h) -> {
-    ADDREPLICAPROP_OP(ADDREPLICAPROP) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           PROPERTY_PROP,
@@ -730,28 +648,22 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       if (StringUtils.isNotBlank((String) map.get(SHARD_UNIQUE)) &&
           SliceMutator.SLICE_UNIQUE_BOOLEAN_PROPERTIES.contains(property.toLowerCase(Locale.ROOT)) &&
           uniquePerSlice == false) {
-          throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
+        throw new SolrException(ErrorCode.BAD_REQUEST,
             "Overseer replica property command received for property " + property +
                 " with the " + SHARD_UNIQUE +
                 " parameter set to something other than 'true'. No action taken.");
       }
       return map;
-      }
+    }),
-    },
+    DELETEREPLICAPROP_OP(DELETEREPLICAPROP, (req, rsp, h) -> {
-    DELETEREPLICAPROP_OP(DELETEREPLICAPROP) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           PROPERTY_PROP,
           SHARD_ID_PROP,
           REPLICA_PROP);
       return req.getParams().getAll(map, PROPERTY_PROP);
-      }
+    }),
-    },
+    BALANCESHARDUNIQUE_OP(BALANCESHARDUNIQUE, (req, rsp, h) -> {
-    BALANCESHARDUNIQUE_OP(BALANCESHARDUNIQUE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       Map<String, Object> map = req.getParams().required().getAll(null,
           COLLECTION_PROP,
           PROPERTY_PROP);
@@ -768,19 +680,12 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       }
 
       return req.getParams().getAll(map, ONLY_ACTIVE_NODES, SHARD_UNIQUE);
-      }
+    }),
-    },
+    REBALANCELEADERS_OP(REBALANCELEADERS, (req, rsp, h) -> {
-    REBALANCELEADERS_OP(REBALANCELEADERS) {
+      new RebalanceLeaders(req, rsp, h).execute();
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
-        new RebalanceLeaders(req,rsp,h).execute();
       return null;
-      }
+    }),
-    },
+    MODIFYCOLLECTION_OP(MODIFYCOLLECTION, (req, rsp, h) -> {
-    MODIFYCOLLECTION_OP(MODIFYCOLLECTION) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
-
       Map<String, Object> m = req.getParams().getAll(null, MODIFIABLE_COLL_PROPS);
       if (m.isEmpty()) throw new SolrException(ErrorCode.BAD_REQUEST,
           formatString("no supported values provided rule, snitch, maxShardsPerNode, replicationFactor, collection.configName"));
@@ -790,18 +695,10 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       for (String prop : MODIFIABLE_COLL_PROPS) DocCollection.verifyProp(m, prop);
       verifyRuleParams(h.coreContainer, m);
       return m;
-      }
+    }),
-    },
+    MIGRATESTATEFORMAT_OP(MIGRATESTATEFORMAT, (req, rsp, h) -> req.getParams().required().getAll(null, COLLECTION_PROP)),
-    MIGRATESTATEFORMAT_OP(MIGRATESTATEFORMAT) {
+
-      @Override
+    BACKUP_OP(BACKUP, (req, rsp, h) -> {
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler handler)
-          throws Exception {
-        return req.getParams().required().getAll(null, COLLECTION_PROP);
-      }
-    },
-    BACKUP_OP(BACKUP) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       req.getParams().required().check(NAME, COLLECTION_PROP);
 
       String collectionName = req.getParams().get(COLLECTION_PROP);
@@ -840,11 +737,8 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       Map<String, Object> params = req.getParams().getAll(null, NAME, COLLECTION_PROP);
       params.put(CoreAdminParams.BACKUP_LOCATION, location);
       return params;
-      }
+    }),
-    },
+    RESTORE_OP(RESTORE, (req, rsp, h) -> {
-    RESTORE_OP(RESTORE) {
-      @Override
-      Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception {
       req.getParams().required().check(NAME, COLLECTION_PROP);
 
       String collectionName = SolrIdentifierValidator.validateCollectionName(req.getParams().get(COLLECTION_PROP));
@@ -887,28 +781,24 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       req.getParams().getAll(params, COLL_CONF, REPLICATION_FACTOR, MAX_SHARDS_PER_NODE, STATE_FORMAT, AUTO_ADD_REPLICAS);
       copyPropertiesWithPrefix(req.getParams(), params, COLL_PROP_PREFIX);
       return params;
-      }
+    });
-    };
+    public final CollectionOp fun;
     CollectionAction action;
     long timeOut;
     boolean sendToOCPQueue;
 
-    CollectionOperation(CollectionAction action) {
+    CollectionOperation(CollectionAction action, CollectionOp fun) {
-      this(action, DEFAULT_COLLECTION_OP_TIMEOUT, true);
+      this(action, DEFAULT_COLLECTION_OP_TIMEOUT, true, fun);
     }
 
-    CollectionOperation(CollectionAction action, long timeOut, boolean sendToOCPQueue) {
+    CollectionOperation(CollectionAction action, long timeOut, boolean sendToOCPQueue, CollectionOp fun) {
       this.action = action;
       this.timeOut = timeOut;
       this.sendToOCPQueue = sendToOCPQueue;
+      this.fun = fun;
 
     }
 
-    /**
-     * All actions must implement this method. If a non null map is returned , the action name is added to
-     * the map and sent to overseer for processing. If it returns a null, the call returns immediately
-     */
-    abstract Map<String, Object> call(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception;
 
     public static CollectionOperation get(CollectionAction action) {
       for (CollectionOperation op : values()) {
@@ -916,6 +806,12 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
       }
       throw new SolrException(ErrorCode.SERVER_ERROR, "No such action" + action);
     }
+
+    @Override
+    public Map<String, Object> execute(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h)
+        throws Exception {
+      return fun.execute(req, rsp, h);
+    }
   }
 
   private static void forceLeaderElection(SolrQueryRequest req, CollectionsHandler handler) {
@@ -1096,6 +992,11 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
     }
   }
 
+  interface CollectionOp {
+    Map<String, Object> execute(SolrQueryRequest req, SolrQueryResponse rsp, CollectionsHandler h) throws Exception;
+    
+  }
+
   public static final List<String> MODIFIABLE_COLL_PROPS = Arrays.asList(
       RULE,
       SNITCH,