diff --git a/.gitignore b/.gitignore
index b731787052..d22c792f43 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,6 +70,7 @@ jmeter/src/main/resources/*-JMeter*.csv
 jmeter/src/main/resources/*ReportsDashboard*.csv
 jmeter/src/main/resources/dashboard/*ReportsDashboard*.csv
 jmeter/src/main/resources/*FileExtractionExample.csv
+jmeter/src/main/resources/*_Summary-Report.csv
 
 ninja/devDb.mv.db
 
diff --git a/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/SingletonUnitTest.java b/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/SingletonUnitTest.java
index d5133ae976..3d233327e3 100644
--- a/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/SingletonUnitTest.java
+++ b/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/SingletonUnitTest.java
@@ -1,47 +1,70 @@
 package com.baeldung.readresolvevsreadobject;
 
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
+
+import org.junit.After;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 
 public class SingletonUnitTest {
 
+    private static final String SINGLETON_SER = "singleton.ser";
+
+    @After
+    public void tearDown() {
+        final File file = new File(SINGLETON_SER);
+        if (file.exists()) {
+            file.deleteOnExit();
+        }
+    }
+
     @Test
     public void testSingletonObj_withNoReadResolve() throws ClassNotFoundException, IOException {
         // Serialization
-        FileOutputStream fos = new FileOutputStream("singleton.ser");
+        FileOutputStream fos = new FileOutputStream(SINGLETON_SER);
         ObjectOutputStream oos = new ObjectOutputStream(fos);
         Singleton actualSingletonObject = Singleton.getInstance();
         oos.writeObject(actualSingletonObject);
 
         // Deserialization
         Singleton deserializedSingletonObject = null;
-        FileInputStream fis = new FileInputStream("singleton.ser");
+        FileInputStream fis = new FileInputStream(SINGLETON_SER);
         ObjectInputStream ois = new ObjectInputStream(fis);
         deserializedSingletonObject = (Singleton) ois.readObject();
         // remove readResolve() from Singleton class and uncomment this to test.
         //assertNotEquals(actualSingletonObject.hashCode(), deserializedSingletonObject.hashCode());
+
+        fos.close();
+        oos.close();
+        fis.close();
+        ois.close();
     }
 
     @Test
     public void testSingletonObj_withCustomReadResolve()
             throws ClassNotFoundException, IOException {
         // Serialization
-        FileOutputStream fos = new FileOutputStream("singleton.ser");
+        FileOutputStream fos = new FileOutputStream(SINGLETON_SER);
         ObjectOutputStream oos = new ObjectOutputStream(fos);
         Singleton actualSingletonObject = Singleton.getInstance();
         oos.writeObject(actualSingletonObject);
 
         // Deserialization
-        Singleton deserializedSingletonObject = null;
-        FileInputStream fis = new FileInputStream("singleton.ser");
+        Singleton deserializedSingletonObject;
+        FileInputStream fis = new FileInputStream(SINGLETON_SER);
         ObjectInputStream ois = new ObjectInputStream(fis);
         deserializedSingletonObject = (Singleton) ois.readObject();
         assertEquals(actualSingletonObject.hashCode(), deserializedSingletonObject.hashCode());
+
+        fos.close();
+        oos.close();
+        fis.close();
+        ois.close();
     }
 }
diff --git a/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/UserUnitTest.java b/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/UserUnitTest.java
index ffd56d67e9..cd07fd2bc7 100644
--- a/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/UserUnitTest.java
+++ b/core-java-modules/core-java-serialization/src/test/java/com/baeldung/readresolvevsreadobject/UserUnitTest.java
@@ -1,52 +1,74 @@
 package com.baeldung.readresolvevsreadobject;
 
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
+
+import org.junit.After;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 
 public class UserUnitTest {
 
+    private static final String USER_SER = "user.ser";
+
+    @After
+    public void tearDown() {
+        final File file = new File(USER_SER);
+        if (file.exists()) {
+            file.deleteOnExit();
+        }
+    }
+
     @Test
-    public void testDeserializeObj_withOverriddenReadObject()
-            throws ClassNotFoundException, IOException {
+    public void testDeserializeObj_withOverriddenReadObject() throws ClassNotFoundException, IOException {
         // Serialization
-        FileOutputStream fos = new FileOutputStream("user.ser");
+        FileOutputStream fos = new FileOutputStream(USER_SER);
         ObjectOutputStream oos = new ObjectOutputStream(fos);
         User acutalObject = new User("Sachin", "Kumar");
         oos.writeObject(acutalObject);
 
         // Deserialization
-        User deserializedUser = null;
-        FileInputStream fis = new FileInputStream("user.ser");
+        User deserializedUser;
+        FileInputStream fis = new FileInputStream(USER_SER);
         ObjectInputStream ois = new ObjectInputStream(fis);
         deserializedUser = (User) ois.readObject();
         assertNotEquals(deserializedUser.hashCode(), acutalObject.hashCode());
         assertEquals(deserializedUser.getUserName(), "Sachin");
         assertEquals(deserializedUser.getPassword(), "Kumar");
+
+        fos.close();
+        oos.close();
+        fis.close();
+        ois.close();
     }
 
     @Test
     public void testDeserializeObj_withDefaultReadObject()
             throws ClassNotFoundException, IOException {
         // Serialization
-        FileOutputStream fos = new FileOutputStream("user.ser");
+        FileOutputStream fos = new FileOutputStream(USER_SER);
         ObjectOutputStream oos = new ObjectOutputStream(fos);
         User acutalObject = new User("Sachin", "Kumar");
         oos.writeObject(acutalObject);
 
         // Deserialization
-        User deserializedUser = null;
-        FileInputStream fis = new FileInputStream("user.ser");
+        User deserializedUser;
+        FileInputStream fis = new FileInputStream(USER_SER);
         ObjectInputStream ois = new ObjectInputStream(fis);
         deserializedUser = (User) ois.readObject();
         assertNotEquals(deserializedUser.hashCode(), acutalObject.hashCode());
         assertEquals(deserializedUser.getUserName(), "Sachin");
         // remove readObject() from User class and uncomment this to test.
         //assertEquals(deserializedUser.getPassword(), "xyzKumar");
+
+        fos.close();
+        oos.close();
+        fis.close();
+        ois.close();
     }
 }
diff --git a/messaging-modules/apache-camel/src/test/java/com/apache/camel/file/processor/FileProcessorIntegrationTest.java b/messaging-modules/apache-camel/src/test/java/com/apache/camel/file/processor/FileProcessorIntegrationTest.java
index bc5de17537..e4390a95e5 100644
--- a/messaging-modules/apache-camel/src/test/java/com/apache/camel/file/processor/FileProcessorIntegrationTest.java
+++ b/messaging-modules/apache-camel/src/test/java/com/apache/camel/file/processor/FileProcessorIntegrationTest.java
@@ -5,6 +5,7 @@ import java.io.File;
 import org.apache.camel.CamelContext;
 import org.apache.camel.builder.RouteBuilder;
 import org.apache.camel.impl.DefaultCamelContext;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
@@ -33,12 +34,18 @@ public class FileProcessorIntegrationTest {
         file2.createNewFile();
     }
 
+    @After
+    public void tearDown() {
+        cleanFolder(new File(SOURCE_FOLDER));
+        cleanFolder(new File(DESTINATION_FOLDER));
+    }
+
     private void cleanFolder(File folder) {
         File[] files = folder.listFiles();
         if (files != null) {
             for (File file : files) {
                 if (file.isFile()) {
-                    file.delete();
+                    file.deleteOnExit();
                 }
             }
         }