Add Get Settings API support to java high-level rest client

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

@@ -43,6 +43,8 @@
 import org.elasticsearch.action.admin.indices.open.OpenIndexResponse;
 import org.elasticsearch.action.admin.indices.refresh.RefreshRequest;
 import org.elasticsearch.action.admin.indices.refresh.RefreshResponse;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsRequest;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsResponse;
 import org.elasticsearch.action.admin.indices.rollover.RolloverRequest;
 import org.elasticsearch.action.admin.indices.rollover.RolloverResponse;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsRequest;
@@ -265,6 +267,28 @@ public void flushAsync(FlushRequest flushRequest, ActionListener<FlushResponse>
                 listener, emptySet(), headers);
     }
 
+    /**
+     * Retrieve the settings of one or more indices
+     * <p>
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-get-settings.html">
+     * Indices Get Settings API on elastic.co</a>
+     */
+    public GetSettingsResponse getSettings(GetSettingsRequest getSettingsRequest, Header... headers) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(getSettingsRequest, RequestConverters::getSettings,
+            GetSettingsResponse::fromXContent, emptySet(), headers);
+    }
+
+    /**
+     * Asynchronously retrieve the settings of one or more indices
+     * <p>
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-get-settings.html">
+     * Indices Get Settings API on elastic.co</a>
+     */
+    public void getSettingsAsync(GetSettingsRequest getSettingsRequest, ActionListener<GetSettingsResponse> listener, Header... headers) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(getSettingsRequest, RequestConverters::getSettings,
+            GetSettingsResponse::fromXContent, listener, emptySet(), headers);
+    }
+
     /**
      * Force merge one or more indices using the Force Merge API
      * <p>

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

@@ -44,6 +44,7 @@
 import org.elasticsearch.action.admin.indices.refresh.RefreshRequest;
 import org.elasticsearch.action.admin.indices.rollover.RolloverRequest;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsRequest;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeType;
 import org.elasticsearch.action.bulk.BulkRequest;
@@ -600,6 +601,22 @@ static Request rollover(RolloverRequest rolloverRequest) throws IOException {
         return request;
     }
 
+    static Request getSettings(GetSettingsRequest getSettingsRequest) throws IOException {
+        String[] indices = getSettingsRequest.indices() == null ? Strings.EMPTY_ARRAY : getSettingsRequest.indices();
+        String[] names = getSettingsRequest.names() == null ? Strings.EMPTY_ARRAY : getSettingsRequest.names();
+
+        String endpoint = endpoint(indices, "_settings", names);
+        Request request = new Request(HttpGet.METHOD_NAME, endpoint);
+
+        Params params = new Params(request);
+        params.withIndicesOptions(getSettingsRequest.indicesOptions());
+        params.withLocal(getSettingsRequest.local());
+        params.withIncludeDefaults(getSettingsRequest.includeDefaults());
+        params.withMasterTimeout(getSettingsRequest.masterNodeTimeout());
+
+        return request;
+    }
+
     static Request indicesExist(GetIndexRequest getIndexRequest) {
         // this can be called with no indices as argument by transport client, not via REST though
         if (getIndexRequest.indices() == null || getIndexRequest.indices().length == 0) {

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

@@ -51,6 +51,8 @@
 import org.elasticsearch.action.admin.indices.rollover.RolloverResponse;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsRequest;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsResponse;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsRequest;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsResponse;
 import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeResponse;
 import org.elasticsearch.action.admin.indices.shrink.ResizeType;
@@ -189,6 +191,108 @@ public void testCreateIndex() throws IOException {
         }
     }
 
+    public void testGetSettings() throws IOException {
+        String indexName = "get_settings_index";
+        Settings basicSettings = Settings.builder()
+            .put("number_of_shards", 1)
+            .put("number_of_replicas", 0)
+            .build();
+        createIndex(indexName, basicSettings);
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices(indexName);
+        GetSettingsResponse getSettingsResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+
+        assertNull(getSettingsResponse.getSetting(indexName, "index.refresh_interval"));
+        assertEquals("1", getSettingsResponse.getSetting(indexName, "index.number_of_shards"));
+
+        updateIndexSettings(indexName, Settings.builder().put("refresh_interval", "30s"));
+
+        GetSettingsResponse updatedResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+        assertEquals("30s", updatedResponse.getSetting(indexName, "index.refresh_interval"));
+    }
+
+    public void testGetSettingsNonExistentIndex() throws IOException {
+        String nonExistentIndex = "index_that_doesnt_exist";
+        assertFalse(indexExists(nonExistentIndex));
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices(nonExistentIndex);
+        ElasticsearchException exception = expectThrows(ElasticsearchException.class,
+            () -> execute(getSettingsRequest, highLevelClient().indices()::getSettings, highLevelClient().indices()::getSettingsAsync));
+        assertEquals(RestStatus.NOT_FOUND, exception.status());
+    }
+
+    public void testGetSettingsFromMultipleIndices() throws IOException {
+        String indexName1 = "get_multiple_settings_one";
+        createIndex(indexName1, Settings.builder().put("number_of_shards", 2).build());
+
+        String indexName2 = "get_multiple_settings_two";
+        createIndex(indexName2, Settings.builder().put("number_of_shards", 3).build());
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices("get_multiple_settings*");
+        GetSettingsResponse getSettingsResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+
+        assertEquals("2", getSettingsResponse.getSetting(indexName1, "index.number_of_shards"));
+        assertEquals("3", getSettingsResponse.getSetting(indexName2, "index.number_of_shards"));
+    }
+
+    public void testGetSettingsFiltered() throws IOException {
+        String indexName = "get_settings_index";
+        Settings basicSettings = Settings.builder()
+            .put("number_of_shards", 1)
+            .put("number_of_replicas", 0)
+            .build();
+        createIndex(indexName, basicSettings);
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices(indexName).names("index.number_of_shards");
+        GetSettingsResponse getSettingsResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+
+        assertNull(getSettingsResponse.getSetting(indexName, "index.number_of_replicas"));
+        assertEquals("1", getSettingsResponse.getSetting(indexName, "index.number_of_shards"));
+        assertEquals(1, getSettingsResponse.getIndexToSettings().get("get_settings_index").size());
+    }
+
+    public void testGetSettingsWithDefaults() throws IOException {
+        String indexName = "get_settings_index";
+        Settings basicSettings = Settings.builder()
+            .put("number_of_shards", 1)
+            .put("number_of_replicas", 0)
+            .build();
+        createIndex(indexName, basicSettings);
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices(indexName).includeDefaults(true);
+        GetSettingsResponse getSettingsResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+
+        assertNotNull(getSettingsResponse.getSetting(indexName, "index.refresh_interval"));
+        assertEquals(IndexSettings.DEFAULT_REFRESH_INTERVAL,
+            getSettingsResponse.getIndexToDefaultSettings().get("get_settings_index").getAsTime("index.refresh_interval", null));
+        assertEquals("1", getSettingsResponse.getSetting(indexName, "index.number_of_shards"));
+    }
+
+    public void testGetSettingsWithDefaultsFiltered() throws IOException {
+        String indexName = "get_settings_index";
+        Settings basicSettings = Settings.builder()
+            .put("number_of_shards", 1)
+            .put("number_of_replicas", 0)
+            .build();
+        createIndex(indexName, basicSettings);
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest()
+            .indices(indexName)
+            .names("index.refresh_interval")
+            .includeDefaults(true);
+        GetSettingsResponse getSettingsResponse = execute(getSettingsRequest, highLevelClient().indices()::getSettings,
+            highLevelClient().indices()::getSettingsAsync);
+
+        assertNull(getSettingsResponse.getSetting(indexName, "index.number_of_replicas"));
+        assertNull(getSettingsResponse.getSetting(indexName, "index.number_of_shards"));
+        assertEquals(0, getSettingsResponse.getIndexToSettings().get("get_settings_index").size());
+        assertEquals(1, getSettingsResponse.getIndexToDefaultSettings().get("get_settings_index").size());
+    }
     public void testPutMapping() throws IOException {
         {
             // Add mappings to index

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

@@ -47,6 +47,7 @@
 import org.elasticsearch.action.admin.indices.refresh.RefreshRequest;
 import org.elasticsearch.action.admin.indices.rollover.RolloverRequest;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsRequest;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeType;
 import org.elasticsearch.action.bulk.BulkRequest;
@@ -76,6 +77,7 @@
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.Streams;
 import org.elasticsearch.common.lucene.uid.Versions;
+import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -405,6 +407,52 @@ public void testDeleteIndex() {
         assertNull(request.getEntity());
     }
 
+    public void testGetSettings() throws IOException {
+        String[] indicesUnderTest = randomBoolean() ? null : randomIndicesNames(0, 5);
+
+        GetSettingsRequest getSettingsRequest = new GetSettingsRequest().indices(indicesUnderTest);
+
+        Map<String, String> expectedParams = new HashMap<>();
+        setRandomMasterTimeout(getSettingsRequest, expectedParams);
+        setRandomIndicesOptions(getSettingsRequest::indicesOptions, getSettingsRequest::indicesOptions, expectedParams);
+
+        setRandomLocal(getSettingsRequest, expectedParams);
+
+        if (randomBoolean()) {
+            //the request object will not have include_defaults present unless it is set to true
+            getSettingsRequest.includeDefaults(randomBoolean());
+            if (getSettingsRequest.includeDefaults()) {
+                expectedParams.put("include_defaults", Boolean.toString(true));
+            }
+        }
+
+        StringJoiner endpoint = new StringJoiner("/", "/", "");
+        if (indicesUnderTest != null && indicesUnderTest.length > 0) {
+            endpoint.add(String.join(",", indicesUnderTest));
+        }
+        endpoint.add("_settings");
+
+        if (randomBoolean()) {
+            String[] names = randomBoolean() ? null : new String[randomIntBetween(0, 3)];
+            if (names != null) {
+                for (int x = 0; x < names.length; x++) {
+                    names[x] = randomAlphaOfLengthBetween(3, 10);
+                }
+            }
+            getSettingsRequest.names(names);
+            if (names != null && names.length > 0) {
+                endpoint.add(String.join(",", names));
+            }
+        }
+
+        Request request = RequestConverters.getSettings(getSettingsRequest);
+
+        assertThat(endpoint.toString(), equalTo(request.getEndpoint()));
+        assertThat(request.getParameters(), equalTo(expectedParams));
+        assertThat(request.getMethod(), equalTo(HttpGet.METHOD_NAME));
+        assertThat(request.getEntity(), nullValue());
+    }
+
     public void testDeleteIndexEmptyIndices() {
         String[] indices = randomBoolean() ? null : Strings.EMPTY_ARRAY;
         ActionRequestValidationException validationException = new DeleteIndexRequest(indices).validate();

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

@@ -50,6 +50,8 @@
 import org.elasticsearch.action.admin.indices.rollover.RolloverResponse;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsRequest;
 import org.elasticsearch.action.admin.indices.settings.put.UpdateSettingsResponse;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsRequest;
+import org.elasticsearch.action.admin.indices.settings.get.GetSettingsResponse;
 import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeResponse;
 import org.elasticsearch.action.admin.indices.shrink.ResizeType;
@@ -775,6 +777,119 @@ public void onFailure(Exception e) {
         }
     }
 
+    public void testGetSettings() throws Exception {
+        RestHighLevelClient client = highLevelClient();
+
+        {
+            Settings settings = Settings.builder().put("number_of_shards", 3).build();
+            CreateIndexResponse createIndexResponse = client.indices().create(new CreateIndexRequest("index", settings));
+            assertTrue(createIndexResponse.isAcknowledged());
+        }
+
+        // tag::get-settings-request
+        GetSettingsRequest request = new GetSettingsRequest().indices("index");
+        // end::get-settings-request
+
+        // tag::get-settings-request-names
+        request.names("index.number_of_shards"); // <1>
+        // end::get-settings-request-names
+
+        // tag::get-settings-request-indicesOptions
+        request.indicesOptions(IndicesOptions.lenientExpandOpen()); // <1>
+        // end::get-settings-request-indicesOptions
+
+        // tag::get-settings-execute
+        GetSettingsResponse getSettingsResponse = client.indices().getSettings(request);
+        // end::get-settings-execute
+
+        // tag::get-settings-response
+        String numberOfShardsString = getSettingsResponse.getSetting("index", "index.number_of_shards"); // <1>
+        Settings indexSettings = getSettingsResponse.getIndexToSettings().get("index"); // <2>
+        Integer numberOfShards = indexSettings.getAsInt("index.number_of_shards", null); // <3>
+        // end::get-settings-response
+
+        assertEquals("3", numberOfShardsString);
+        assertEquals(Integer.valueOf(3), numberOfShards);
+
+        assertNull("refresh_interval returned but was never set!",
+            getSettingsResponse.getSetting("index", "index.refresh_interval"));
+
+        // tag::get-settings-execute-listener
+        ActionListener<GetSettingsResponse> listener =
+            new ActionListener<GetSettingsResponse>() {
+                @Override
+                public void onResponse(GetSettingsResponse GetSettingsResponse) {
+                    // <1>
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    // <2>
+                }
+            };
+        // end::get-settings-execute-listener
+
+        // Replace the empty listener by a blocking listener in test
+        final CountDownLatch latch = new CountDownLatch(1);
+        listener = new LatchedActionListener<>(listener, latch);
+
+        // tag::get-settings-execute-async
+        client.indices().getSettingsAsync(request, listener); // <1>
+        // end::get-settings-execute-async
+
+        assertTrue(latch.await(30L, TimeUnit.SECONDS));
+    }
+
+    public void testGetSettingsWithDefaults() throws Exception {
+        RestHighLevelClient client = highLevelClient();
+
+        {
+            Settings settings = Settings.builder().put("number_of_shards", 3).build();
+            CreateIndexResponse createIndexResponse = client.indices().create(new CreateIndexRequest("index", settings));
+            assertTrue(createIndexResponse.isAcknowledged());
+        }
+
+        GetSettingsRequest request = new GetSettingsRequest().indices("index");
+        request.indicesOptions(IndicesOptions.lenientExpandOpen());
+
+        // tag::get-settings-request-include-defaults
+        request.includeDefaults(true); // <1>
+        // end::get-settings-request-include-defaults
+
+        GetSettingsResponse getSettingsResponse = client.indices().getSettings(request);
+        String numberOfShardsString = getSettingsResponse.getSetting("index", "index.number_of_shards");
+        Settings indexSettings = getSettingsResponse.getIndexToSettings().get("index");
+        Integer numberOfShards = indexSettings.getAsInt("index.number_of_shards", null);
+
+        // tag::get-settings-defaults-response
+        String refreshInterval = getSettingsResponse.getSetting("index", "index.refresh_interval"); // <1>
+        Settings indexDefaultSettings = getSettingsResponse.getIndexToDefaultSettings().get("index"); // <2>
+        // end::get-settings-defaults-response
+
+        assertEquals("3", numberOfShardsString);
+        assertEquals(Integer.valueOf(3), numberOfShards);
+        assertNotNull("with defaults enabled we should get a value for refresh_interval!", refreshInterval);
+
+        assertEquals(refreshInterval, indexDefaultSettings.get("index.refresh_interval"));
+        ActionListener<GetSettingsResponse> listener =
+            new ActionListener<GetSettingsResponse>() {
+                @Override
+                public void onResponse(GetSettingsResponse GetSettingsResponse) {
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                }
+            };
+
+        // Replace the empty listener by a blocking listener in test
+        final CountDownLatch latch = new CountDownLatch(1);
+        listener = new LatchedActionListener<>(listener, latch);
+
+        client.indices().getSettingsAsync(request, listener);
+        assertTrue(latch.await(30L, TimeUnit.SECONDS));
+    }
+
     public void testForceMergeIndex() throws Exception {
         RestHighLevelClient client = highLevelClient();