DATAES-290 - Make joda-time optional dependency.

Original PR: spring-projects#308 and spring-projects#213

Author: sothawo

pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 
-    <modelVersion>4.0.0</modelVersion>
+	<modelVersion>4.0.0</modelVersion>
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-elasticsearch</artifactId>
@@ -144,6 +144,7 @@
 			<groupId>joda-time</groupId>
 			<artifactId>joda-time</artifactId>
 			<version>${jodatime}</version>
+			<optional>true</optional>
 		</dependency>
 
 		<!-- Elasticsearch -->

src/main/java/org/springframework/data/elasticsearch/repository/query/ElasticsearchStringQuery.java

@@ -24,6 +24,7 @@
 import org.springframework.data.elasticsearch.core.query.StringQuery;
 import org.springframework.data.repository.query.ParametersParameterAccessor;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.NumberUtils;
 
 /**
@@ -33,6 +34,7 @@
  * @author Mohsin Husen
  * @author Mark Paluch
  * @author Taylor Ono
+ * @author Peter-Josef Meisch
  */
 public class ElasticsearchStringQuery extends AbstractElasticsearchRepositoryQuery {
 
@@ -45,11 +47,13 @@ public class ElasticsearchStringQuery extends AbstractElasticsearchRepositoryQue
 		if (!conversionService.canConvert(java.util.Date.class, String.class)) {
 			conversionService.addConverter(DateTimeConverters.JavaDateConverter.INSTANCE);
 		}
-		if (!conversionService.canConvert(org.joda.time.ReadableInstant.class, String.class)) {
-			conversionService.addConverter(DateTimeConverters.JodaDateTimeConverter.INSTANCE);
-		}
-		if (!conversionService.canConvert(org.joda.time.LocalDateTime.class, String.class)) {
-			conversionService.addConverter(DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE);
+		if (ClassUtils.isPresent("org.joda.time.DateTimeZone", ElasticsearchStringQuery.class.getClassLoader())) {
+			if (!conversionService.canConvert(org.joda.time.ReadableInstant.class, String.class)) {
+				conversionService.addConverter(DateTimeConverters.JodaDateTimeConverter.INSTANCE);
+			}
+			if (!conversionService.canConvert(org.joda.time.LocalDateTime.class, String.class)) {
+				conversionService.addConverter(DateTimeConverters.JodaLocalDateTimeConverter.INSTANCE);
+			}
 		}
 	}