REST high-level client: add flush API

client/rest-high-level/src/main/java/org/elasticsearch/client/IndicesClient.java

@@ -30,6 +30,8 @@
 import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexResponse;
+import org.elasticsearch.action.admin.indices.flush.FlushRequest;
+import org.elasticsearch.action.admin.indices.flush.FlushResponse;
 import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse;
@@ -237,6 +239,26 @@ public void refreshAsync(RefreshRequest refreshRequest, ActionListener<RefreshRe
                 listener, emptySet(), headers);
     }
 
+    /**
+     * Flush one or more indices using the Flush API
+     * <p>
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-flush.html"> Flush API on elastic.co</a>
+     */
+    public FlushResponse flush(FlushRequest flushRequest, Header... headers) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(flushRequest, Request::flush, FlushResponse::fromXContent,
+                emptySet(), headers);
+    }
+
+    /**
+     * Asynchronously flush one or more indices using the Flush API
+     * <p>
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-flush.html"> Flush API on elastic.co</a>
+     */
+    public void flushAsync(FlushRequest flushRequest, ActionListener<FlushResponse> listener, Header... headers) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(flushRequest, Request::flush, FlushResponse::fromXContent,
+                listener, emptySet(), headers);
+    }
+
     /**
      * Checks if the index (indices) exists or not.
      * <p>

client/rest-high-level/src/main/java/org/elasticsearch/client/Request.java

@@ -35,6 +35,7 @@
 import org.elasticsearch.action.admin.indices.close.CloseIndexRequest;
 import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
+import org.elasticsearch.action.admin.indices.flush.FlushRequest;
 import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;
@@ -219,10 +220,17 @@ static Request putMapping(PutMappingRequest putMappingRequest) throws IOExceptio
 
     static Request refresh(RefreshRequest refreshRequest) {
         String endpoint = endpoint(refreshRequest.indices(), "_refresh");
-
         Params parameters = Params.builder();
         parameters.withIndicesOptions(refreshRequest.indicesOptions());
+        return new Request(HttpPost.METHOD_NAME, endpoint, parameters.getParams(), null);
+    }
 
+    static Request flush(FlushRequest flushRequest) {
+        String endpoint = endpoint(flushRequest.indices(), "_flush");
+        Params parameters = Params.builder();
+        parameters.withIndicesOptions(flushRequest.indicesOptions());
+        parameters.putParam("wait_if_ongoing", Boolean.toString(flushRequest.waitIfOngoing()));
+        parameters.putParam("force", Boolean.toString(flushRequest.force()));
         return new Request(HttpPost.METHOD_NAME, endpoint, parameters.getParams(), null);
     }
 

client/rest-high-level/src/test/java/org/elasticsearch/client/IndicesClientIT.java

@@ -34,6 +34,8 @@
 import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexResponse;
+import org.elasticsearch.action.admin.indices.flush.FlushRequest;
+import org.elasticsearch.action.admin.indices.flush.FlushResponse;
 import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse;
@@ -410,6 +412,32 @@ public void testRefresh() throws IOException {
         }
     }
 
+    public void testFlush() throws IOException {
+        {
+            String index = "index";
+            Settings settings = Settings.builder()
+                    .put("number_of_shards", 1)
+                    .put("number_of_replicas", 0)
+                    .build();
+            createIndex(index, settings);
+            FlushRequest flushRequest = new FlushRequest(index);
+            FlushResponse flushResponse =
+                    execute(flushRequest, highLevelClient().indices()::flush, highLevelClient().indices()::flushAsync);
+            assertThat(flushResponse.getTotalShards(), equalTo(1));
+            assertThat(flushResponse.getSuccessfulShards(), equalTo(1));
+            assertThat(flushResponse.getFailedShards(), equalTo(0));
+            assertThat(flushResponse.getShardFailures(), equalTo(BroadcastResponse.EMPTY));
+        }
+        {
+            String nonExistentIndex = "non_existent_index";
+            assertFalse(indexExists(nonExistentIndex));
+            FlushRequest refreshRequest = new FlushRequest(nonExistentIndex);
+            ElasticsearchException exception = expectThrows(ElasticsearchException.class,
+                    () -> execute(refreshRequest, highLevelClient().indices()::flush, highLevelClient().indices()::flushAsync));
+            assertEquals(RestStatus.NOT_FOUND, exception.status());
+        }
+    }
+
     public void testExistsAlias() throws IOException {
         GetAliasesRequest getAliasesRequest = new GetAliasesRequest("alias");
         assertFalse(execute(getAliasesRequest, highLevelClient().indices()::existsAlias, highLevelClient().indices()::existsAliasAsync));

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestTests.java

@@ -37,6 +37,7 @@
 import org.elasticsearch.action.admin.indices.close.CloseIndexRequest;
 import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
+import org.elasticsearch.action.admin.indices.flush.FlushRequest;
 import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;
@@ -537,15 +538,43 @@ public void testIndex() throws IOException {
     }
 
     public void testRefresh() {
-        String[] indices = randomIndicesNames(1, 5);
+        String[] indices = randomIndicesNames(0, 5);
         RefreshRequest refreshRequest = new RefreshRequest(indices);
-
         Map<String, String> expectedParams = new HashMap<>();
         setRandomIndicesOptions(refreshRequest::indicesOptions, refreshRequest::indicesOptions, expectedParams);
-
         Request request = Request.refresh(refreshRequest);
-        StringJoiner endpoint = new StringJoiner("/", "/", "").add(String.join(",", indices)).add("_refresh");
-        assertThat(endpoint.toString(), equalTo(request.getEndpoint()));
+        StringJoiner endpoint = new StringJoiner("/", "/", "");
+        if (indices.length > 0) {
+            endpoint.add(String.join(",", indices));
+        }
+        endpoint.add("_refresh");
+        assertThat(request.getEndpoint(), equalTo(endpoint.toString()));
+        assertThat(request.getParameters(), equalTo(expectedParams));
+        assertThat(request.getEntity(), nullValue());
+        assertThat(request.getMethod(), equalTo(HttpPost.METHOD_NAME));
+    }
+
+    public void testFlush() {
+        String[] indices = randomIndicesNames(0, 5);
+        FlushRequest flushRequest = new FlushRequest(indices);
+        Map<String, String> expectedParams = new HashMap<>();
+        setRandomIndicesOptions(flushRequest::indicesOptions, flushRequest::indicesOptions, expectedParams);
+        if (randomBoolean()) {
+            flushRequest.force(randomBoolean());
+        }
+        expectedParams.put("force", Boolean.toString(flushRequest.force()));
+        if (randomBoolean()) {
+            flushRequest.waitIfOngoing(randomBoolean());
+        }
+        expectedParams.put("wait_if_ongoing", Boolean.toString(flushRequest.waitIfOngoing()));
+
+        Request request = Request.flush(flushRequest);
+        StringJoiner endpoint = new StringJoiner("/", "/", "");
+        if (indices.length > 0) {
+            endpoint.add(String.join(",", indices));
+        }
+        endpoint.add("_flush");
+        assertThat(request.getEndpoint(), equalTo(endpoint.toString()));
         assertThat(request.getParameters(), equalTo(expectedParams));
         assertThat(request.getEntity(), nullValue());
         assertThat(request.getMethod(), equalTo(HttpPost.METHOD_NAME));

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/IndicesClientDocumentationIT.java

@@ -33,6 +33,8 @@
 import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.elasticsearch.action.admin.indices.delete.DeleteIndexResponse;
+import org.elasticsearch.action.admin.indices.flush.FlushRequest;
+import org.elasticsearch.action.admin.indices.flush.FlushResponse;
 import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse;
@@ -691,6 +693,82 @@ public void onFailure(Exception e) {
         }
     }
 
+    public void testFlushIndex() throws Exception {
+        RestHighLevelClient client = highLevelClient();
+
+        {
+            createIndex("index1", Settings.EMPTY);
+        }
+
+        {
+            // tag::flush-request
+            FlushRequest request = new FlushRequest("index1"); // <1>
+            FlushRequest requestMultiple = new FlushRequest("index1", "index2"); // <2>
+            FlushRequest requestAll = new FlushRequest(); // <3>
+            // end::flush-request
+
+            // tag::flush-request-indicesOptions
+            request.indicesOptions(IndicesOptions.lenientExpandOpen()); // <1>
+            // end::flush-request-indicesOptions
+
+            // tag::flush-request-wait
+            request.waitIfOngoing(true); // <1>
+            // end::flush-request-wait
+
+            // tag::flush-request-force
+            request.force(true); // <1>
+            // end::flush-request-force
+
+            // tag::flush-execute
+            FlushResponse flushResponse = client.indices().flush(request);
+            // end::flush-execute
+
+            // tag::flush-response
+            int totalShards = flushResponse.getTotalShards(); // <1>
+            int successfulShards = flushResponse.getSuccessfulShards(); // <2>
+            int failedShards = flushResponse.getFailedShards(); // <3>
+            DefaultShardOperationFailedException[] failures = flushResponse.getShardFailures(); // <4>
+            // end::flush-response
+
+            // tag::flush-execute-listener
+            ActionListener<FlushResponse> listener = new ActionListener<FlushResponse>() {
+                @Override
+                public void onResponse(FlushResponse refreshResponse) {
+                    // <1>
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    // <2>
+                }
+            };
+            // end::flush-execute-listener
+
+            // Replace the empty listener by a blocking listener in test
+            final CountDownLatch latch = new CountDownLatch(1);
+            listener = new LatchedActionListener<>(listener, latch);
+
+            // tag::flush-execute-async
+            client.indices().flushAsync(request, listener); // <1>
+            // end::flush-execute-async
+
+            assertTrue(latch.await(30L, TimeUnit.SECONDS));
+        }
+
+        {
+            // tag::flush-notfound
+            try {
+                FlushRequest request = new FlushRequest("does_not_exist");
+                client.indices().flush(request);
+            } catch (ElasticsearchException exception) {
+                if (exception.status() == RestStatus.NOT_FOUND) {
+                    // <1>
+                }
+            }
+            // end::flush-notfound
+        }
+    }
+
     public void testCloseIndex() throws Exception {
         RestHighLevelClient client = highLevelClient();
 

docs/java-rest/high-level/indices/flush.asciidoc

@@ -0,0 +1,96 @@
+[[java-rest-high-flush]]
+=== Flush API
+
+[[java-rest-high-flush-request]]
+==== Flush Request
+
+A `FlushRequest` can be applied to one or more indices, or even on `_all` the indices:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-request]
+--------------------------------------------------
+<1> Flush one index
+<2> Flush multiple indices
+<3> Flush all the indices
+
+==== Optional arguments
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-request-indicesOptions]
+--------------------------------------------------
+<1> Setting `IndicesOptions` controls how unavailable indices are resolved and
+how wildcard expressions are expanded
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-request-wait]
+--------------------------------------------------
+<1> Set the `wait_if_ongoing` flag to `true`
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-request-force]
+--------------------------------------------------
+<1> Set the `force` flag to `true`
+
+[[java-rest-high-flush-sync]]
+==== Synchronous Execution
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-execute]
+--------------------------------------------------
+
+[[java-rest-high-flush-async]]
+==== Asynchronous Execution
+
+The asynchronous execution of a flush request requires both the `FlushRequest`
+instance and an `ActionListener` instance to be passed to the asynchronous
+method:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-execute-async]
+--------------------------------------------------
+<1> The `FlushRequest` to execute and the `ActionListener` to use when
+the execution completes
+
+The asynchronous method does not block and returns immediately. Once it is
+completed the `ActionListener` is called back using the `onResponse` method
+if the execution successfully completed or using the `onFailure` method if
+it failed.
+
+A typical listener for `FlushResponse` looks like:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-execute-listener]
+--------------------------------------------------
+<1> Called when the execution is successfully completed. The response is
+provided as an argument
+<2> Called in case of failure. The raised exception is provided as an argument
+
+[[java-rest-high-flush-response]]
+==== Flush Response
+
+The returned `FlushResponse` allows to retrieve information about the
+executed operation as follows:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-response]
+--------------------------------------------------
+<1> Total number of shards hit by the flush request
+<2> Number of shards where the flush has succeeded
+<3> Number of shards where the flush has failed
+<4> A list of failures if the operation failed on one or more shards
+
+By default, if the indices were not found, an `ElasticsearchException` will be thrown:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[flush-notfound]
+--------------------------------------------------
+<1> Do something if the indices to be flushed were not found

docs/java-rest/high-level/supported-apis.asciidoc

@@ -53,6 +53,7 @@ Index Management::
 * <<java-rest-high-shrink-index>>
 * <<java-rest-high-split-index>>
 * <<java-rest-high-refresh>>
+* <<java-rest-high-flush>>
 * <<java-rest-high-rollover-index>>
 
 Mapping Management::
@@ -70,6 +71,7 @@ include::indices/close_index.asciidoc[]
 include::indices/shrink_index.asciidoc[]
 include::indices/split_index.asciidoc[]
 include::indices/refresh.asciidoc[]
+include::indices/flush.asciidoc[]
 include::indices/rollover.asciidoc[]
 include::indices/put_mapping.asciidoc[]
 include::indices/update_aliases.asciidoc[]