Polish gh-304

Author: Steve Riesenberg

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/JdbcOAuth2AuthorizationService.java

@@ -29,6 +29,7 @@
 import java.util.Set;
 import java.util.function.Function;
 
+import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.Module;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
@@ -436,10 +437,9 @@ protected final ObjectMapper getObjectMapper() {
 			return this.objectMapper;
 		}
 
-		@SuppressWarnings("unchecked")
 		private Map<String, Object> parseMap(String data) {
 			try {
-				return this.objectMapper.readValue(data, Map.class);
+				return this.objectMapper.readValue(data, new TypeReference<Map<String, Object>>() {});
 			} catch (Exception ex) {
 				throw new IllegalArgumentException(ex.getMessage(), ex);
 			}
@@ -542,7 +542,6 @@ private <T extends AbstractOAuth2Token> List<SqlParameterValue> toSqlParameterLi
 			return parameters;
 		}
 
-		@SuppressWarnings("unchecked")
 		private String writeMap(Map<String, Object> data) {
 			try {
 				return this.objectMapper.writeValueAsString(data);