diff --git a/history/taskana-loghistory-provider/src/main/java/pro/taskana/loghistory/impl/LogfileHistoryServiceImpl.java b/history/taskana-loghistory-provider/src/main/java/pro/taskana/loghistory/impl/LogfileHistoryServiceImpl.java
index edb0aa29b..e9307066f 100644
--- a/history/taskana-loghistory-provider/src/main/java/pro/taskana/loghistory/impl/LogfileHistoryServiceImpl.java
+++ b/history/taskana-loghistory-provider/src/main/java/pro/taskana/loghistory/impl/LogfileHistoryServiceImpl.java
@@ -80,7 +80,7 @@ public class LogfileHistoryServiceImpl implements TaskanaHistory {
   }
 
   private Properties readPropertiesFromFile(String propertiesFile) {
-    java.util.Properties props = new Properties();
+    Properties props = new Properties();
     boolean loadFromClasspath = loadFromClasspath(propertiesFile);
     try {
       if (loadFromClasspath) {
@@ -93,7 +93,9 @@ public class LogfileHistoryServiceImpl implements TaskanaHistory {
           LOGGER.debug("properties were loaded from file {} from classpath.", propertiesFile);
         }
       } else {
-        props.load(new FileInputStream(propertiesFile));
+        try (FileInputStream stream = new FileInputStream(propertiesFile)) {
+          props.load(stream);
+        }
         LOGGER.debug("properties were loaded from file {}.", propertiesFile);
       }
     } catch (IOException e) {
diff --git a/history/taskana-simplehistory-rest-spring/src/main/java/pro/taskana/simplehistory/rest/assembler/TaskHistoryEventListResourceAssembler.java b/history/taskana-simplehistory-rest-spring/src/main/java/pro/taskana/simplehistory/rest/assembler/TaskHistoryEventListResourceAssembler.java
index d065c15b5..0622166da 100644
--- a/history/taskana-simplehistory-rest-spring/src/main/java/pro/taskana/simplehistory/rest/assembler/TaskHistoryEventListResourceAssembler.java
+++ b/history/taskana-simplehistory-rest-spring/src/main/java/pro/taskana/simplehistory/rest/assembler/TaskHistoryEventListResourceAssembler.java
@@ -5,6 +5,7 @@ import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.linkTo;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import javax.servlet.http.HttpServletRequest;
 import org.springframework.hateoas.IanaLinkRelations;
 import org.springframework.hateoas.Link;
@@ -67,7 +68,8 @@ public class TaskHistoryEventListResourceAssembler {
 
   private UriComponentsBuilder getBaseUri() {
     HttpServletRequest request =
-        ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
+        ((ServletRequestAttributes) Objects.requireNonNull(
+            RequestContextHolder.getRequestAttributes())).getRequest();
     UriComponentsBuilder baseUri =
         ServletUriComponentsBuilder.fromServletMapping(request).path(request.getRequestURI());
 
diff --git a/lib/taskana-core/src/main/java/pro/taskana/TaskanaEngineConfiguration.java b/lib/taskana-core/src/main/java/pro/taskana/TaskanaEngineConfiguration.java
index 6b0737647..d7a278d4e 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/TaskanaEngineConfiguration.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/TaskanaEngineConfiguration.java
@@ -293,7 +293,6 @@ public class TaskanaEngineConfiguration {
     return roleMap;
   }
 
-  @SuppressWarnings("unused")
   public void setRoleMap(Map<TaskanaRole, Set<String>> roleMap) {
     this.roleMap = roleMap;
   }
@@ -589,7 +588,9 @@ public class TaskanaEngineConfiguration {
           LOGGER.debug("Role properties were loaded from file {} from classpath.", propertiesFile);
         }
       } else {
-        props.load(new FileInputStream(propertiesFile));
+        try (FileInputStream stream = new FileInputStream(propertiesFile)) {
+          props.load(stream);
+        }
         LOGGER.debug("Role properties were loaded from file {}.", propertiesFile);
       }
     } catch (IOException e) {