DATASOLR-484 Add possibility to optimize collection

src/main/java/org/springframework/data/solr/core/SolrOperations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2017 the original author or authors.
+ * Copyright 2012 - 2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,11 +15,13 @@
  */
 package org.springframework.data.solr.core;
 
+import java.io.IOException;
 import java.time.Duration;
 import java.util.Collection;
 import java.util.Optional;
 
 import org.apache.solr.client.solrj.SolrClient;
+import org.apache.solr.client.solrj.SolrServerException;
 import org.apache.solr.client.solrj.response.SolrPingResponse;
 import org.apache.solr.client.solrj.response.UpdateResponse;
 import org.apache.solr.common.SolrInputDocument;
@@ -49,6 +51,7 @@
  * @author Francisco Spaeth
  * @author Shiradwade Sateesh Krishna
  * @author David Webb
+ * @author Radek Mensik
  */
 public interface SolrOperations {
 
@@ -511,4 +514,22 @@ <T> FacetAndHighlightPage<T> queryForFacetAndHighlightPage(String collection, Fa
 	 */
 	SchemaOperations getSchemaOperations(String collection);
 
+
+	/**
+	 * Calls SolrClien.optmize, which has following documentation:
+	 *
+	 * Performs an explicit optimize, causing a merge of all segments to one.
+	 *
+	 * waitFlush=true and waitSearcher=true to be inline with the defaults for plain HTTP access
+	 *
+	 * Note: In most cases it is not required to do explicit optimize
+	 *
+	 * @param collection the Solr collection to send the optimize to
+	 *
+	 * @return an {@link org.apache.solr.client.solrj.response.UpdateResponse} containing the response
+	 *         from the server
+	 *
+	 */
+	UpdateResponse optimize(String collection);
+
 }

src/main/java/org/springframework/data/solr/core/SolrTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2017 the original author or authors.
+ * Copyright 2012 - 2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -91,6 +91,7 @@
  * @author Petar Tahchiev
  * @author Mark Paluch
  * @author Juan Manuel de Blas
+ * @author Radek Mensik
  */
 public class SolrTemplate implements SolrOperations, InitializingBean, ApplicationContextAware {
 
@@ -726,6 +727,11 @@ public void afterPropertiesSet() {
 		registerPersistenceExceptionTranslator();
 	}
 
+	@Override
+	public UpdateResponse optimize(String collection) {
+		return execute(solrClient -> solrClient.optimize(collection));
+	}
+
 	private void registerPersistenceExceptionTranslator() {
 		if (this.applicationContext != null
 				&& this.applicationContext.getBeansOfType(PersistenceExceptionTranslator.class).isEmpty()) {

src/test/java/org/springframework/data/solr/core/SolrTemplateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2017 the original author or authors.
+ * Copyright 2012 - 2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -85,6 +85,7 @@
  * @author Christoph Strobl
  * @author Joachim Uhrlass
  * @author Francisco Spaeth
+ * @author Radek Mensik
  */
 @RunWith(MockitoJUnitRunner.Silent.class)
 public class SolrTemplateTests {
@@ -521,6 +522,16 @@ public void queryForHighlightPageShouldUseRequestMethodCorrectly() throws IOExce
 		verify(solrClientMock, times(1)).query(any(), any(SolrParams.class), eq(SolrRequest.METHOD.PUT));
 	}
 
+	@Test
+	public void testOptimize() throws IOException, SolrServerException {
+		when(solrClientMock.optimize(eq(COLLECTION_NAME)))
+				.thenReturn(new UpdateResponse());
+		UpdateResponse updateResponse = solrTemplate.optimize(COLLECTION_NAME);
+		assertNotNull(updateResponse);
+		verify(solrClientMock, times(1)).optimize(eq(COLLECTION_NAME));
+	}
+
+
 	static class DocumentWithIndexAnnotations {
 
 		@Id String id;