Additinal fixes for resources not being released

More fixes for input streams not being properly closed,
with unit tests and other minor improvements (code cleanup and coding conventions).

Change-Id: I6751f924a1469d49b996e4f1d6c61371af6714b1
Issue-ID: SDC-291
Signed-off-by: vempo <vitaliy.emporopulo@amdocs.com>

9 files changed, 229 insertions, 87 deletions

diff --git a/common/openecomp-common-configuration-management/openecomp-configuration-management-core/src/main/java/org/openecomp/config/impl/ConfigurationChangeNotifier.java b/common/openecomp-common-configuration-management/openecomp-configuration-management-core/src/main/java/org/openecomp/config/impl/ConfigurationChangeNotifier.java
index 5c3df4a56d..3922720d48 100644
--- a/common/openecomp-common-configuration-management/openecomp-configuration-management-core/src/main/java/org/openecomp/config/impl/ConfigurationChangeNotifier.java
+++ b/common/openecomp-common-configuration-management/openecomp-configuration-management-core/src/main/java/org/openecomp/config/impl/ConfigurationChangeNotifier.java
@@ -24,10 +24,10 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.Vector;
 import java.util.concurrent.ExecutorService;
@@ -44,15 +44,15 @@ import javax.management.ObjectName;
  */
 public final class ConfigurationChangeNotifier {
 
-  private HashMap<String, List<NotificationData>> store = new HashMap<>();
-  private ScheduledExecutorService executor =
+  private final HashMap<String, List<NotificationData>> store = new HashMap<>();
+  private final ScheduledExecutorService executor =
       Executors.newScheduledThreadPool(5, ConfigurationUtils.getThreadFactory());
-  private ExecutorService notificationExcecutor =
+  private final ExecutorService notificationExecutor =
       Executors.newCachedThreadPool(ConfigurationUtils.getThreadFactory());
-  private Map<String, WatchService> watchServiceCollection =
+  private final Map<String, WatchService> watchServiceCollection =
       Collections.synchronizedMap(new HashMap<>());
 
-  {
+  static {
     if (!Thread.currentThread().getStackTrace()[2].getClassName()
         .equals(ConfigurationImpl.class.getName())) {
       throw new RuntimeException("Illegal access.");
@@ -66,13 +66,13 @@ public final class ConfigurationChangeNotifier {
    */
   public ConfigurationChangeNotifier(Map<String, AggregateConfiguration> inMemoryConfig) {
     executor.scheduleWithFixedDelay(() -> this
-        .pollFilesystemAndUpdateConfigurationIfREquired(inMemoryConfig,
+        .pollFilesystemAndUpdateConfigurationIfRequired(inMemoryConfig,
             System.getProperty("config.location"), false), 1, 1, TimeUnit.MILLISECONDS);
     executor.scheduleWithFixedDelay(() -> this
-        .pollFilesystemAndUpdateConfigurationIfREquired(inMemoryConfig,
+        .pollFilesystemAndUpdateConfigurationIfRequired(inMemoryConfig,
             System.getProperty("tenant.config.location"), true), 1, 1, TimeUnit.MILLISECONDS);
     executor.scheduleWithFixedDelay(() -> this
-        .pollFilesystemAndUpdateNodeSpecificConfigurationIfREquired(
+        .pollFilesystemAndUpdateNodeSpecificConfigurationIfRequired(
             System.getProperty("node.config.location")), 1, 1, TimeUnit.MILLISECONDS);
   }
 
@@ -91,13 +91,13 @@ public final class ConfigurationChangeNotifier {
   }
 
   /**
-   * Poll filesystem and update configuration if r equired.
+   * Poll filesystem and update configuration if required.
    *
    * @param inMemoryConfig   the in memory config
    * @param location         the location
    * @param isTenantLocation the is tenant location
    */
-  public void pollFilesystemAndUpdateConfigurationIfREquired(
+  public void pollFilesystemAndUpdateConfigurationIfRequired(
       Map<String, AggregateConfiguration> inMemoryConfig, String location,
       boolean isTenantLocation) {
     try {
@@ -132,20 +132,19 @@ public final class ConfigurationChangeNotifier {
               updateConfigurationValues(tenantNamespaceArray[0], tenantNamespaceArray[1], map);
             }
           } else {
-            Iterator<String> repoKeys = inMemoryConfig.keySet().iterator();
-            while (repoKeys.hasNext()) {
-              repositoryKey = repoKeys.next();
+            for (String configKey : inMemoryConfig.keySet()) {
+              repositoryKey = configKey;
               AggregateConfiguration config = inMemoryConfig.get(repositoryKey);
               if (config.containsConfig(file)) {
                 LinkedHashMap origConfig = ConfigurationUtils.toMap(config.getFinalConfiguration());
                 config.removeConfig(file);
                 LinkedHashMap latestConfig =
-                    ConfigurationUtils.toMap(config.getFinalConfiguration());
+                        ConfigurationUtils.toMap(config.getFinalConfiguration());
                 Map map = ConfigurationUtils.diff(origConfig, latestConfig);
                 String[] tenantNamespaceArray =
-                    repositoryKey.split(Constants.KEY_ELEMENTS_DELEMETER);
+                        repositoryKey.split(Constants.KEY_ELEMENTS_DELEMETER);
                 updateConfigurationValues(tenantNamespaceArray[0], tenantNamespaceArray[1],
-                    map);
+                        map);
               }
             }
           }
@@ -169,26 +168,26 @@ public final class ConfigurationChangeNotifier {
   }
 
   /**
-   * Poll filesystem and update node specific configuration if r equired.
+   * Poll filesystem and update node specific configuration if required.
    *
    * @param location the location
    */
-  public void pollFilesystemAndUpdateNodeSpecificConfigurationIfREquired(String location) {
+  public void pollFilesystemAndUpdateNodeSpecificConfigurationIfRequired(String location) {
     try {
       Set<Path> paths = watchForChange(location);
       if (paths != null) {
         for (Path path : paths) {
           File file = path.toAbsolutePath().toFile();
-          String repositoryKey = null;
+
           if (ConfigurationUtils.isConfig(file)) {
-            repositoryKey = ConfigurationUtils.getConfigurationRepositoryKey(file);
+            String repositoryKey = ConfigurationUtils.getConfigurationRepositoryKey(file);
             ConfigurationRepository.lookup().populateOverrideConfigurtaion(repositoryKey, file);
           } else {
             ConfigurationRepository.lookup().removeOverrideConfigurtaion(file);
           }
         }
       }
-    } catch (Throwable exception) {
+    } catch (Exception exception) {
       exception.printStackTrace();
     }
   }
@@ -241,7 +240,7 @@ public final class ConfigurationChangeNotifier {
 
   private void triggerScanning(String key) {
     if (store.get(key) != null) {
-      notificationExcecutor.submit(() -> scanForChanges(key));
+      notificationExecutor.submit(() -> scanForChanges(key));
     } else {
       throw new IllegalArgumentException("Notification service for " + key + " is suspended.");
     }
@@ -250,13 +249,9 @@ public final class ConfigurationChangeNotifier {
   private void scanForChanges(String key) {
     List<NotificationData> list = store.get(key);
     if (list != null) {
-      int size = list.size();
-      for (int i = 0; i < size; i++) {
-        NotificationData notificationData = list.get(i);
-        if (notificationData.isChanged()) {
-          notificationExcecutor.submit(() -> sendNotification(notificationData));
-        }
-      }
+      list.stream()
+              .filter(NotificationData::isChanged)
+              .forEach(notificationData -> notificationExecutor.submit(() -> sendNotification(notificationData)));
     }
   }
 
@@ -321,24 +316,24 @@ public final class ConfigurationChangeNotifier {
   /**
    * The type Notification data.
    */
-  class NotificationData {
+  static class NotificationData {
 
     /**
      * The Tenant.
      */
-    String tenant;
+    final String tenant;
     /**
      * The Namespace.
      */
-    String namespace;
+    final String namespace;
     /**
      * The Key.
      */
-    String key;
+    final String key;
     /**
      * The Myself.
      */
-    ConfigurationChangeListener myself;
+    final ConfigurationChangeListener myself;
     /**
      * The Current value.
      */
@@ -381,8 +376,17 @@ public final class ConfigurationChangeNotifier {
         return false;
       }
       NotificationData nd = (NotificationData) obj;
-      return tenant.equals(nd.tenant) && namespace.equals(nd.namespace) && key.equals(nd.key)
-          && myself.equals(nd.myself);
+      return Objects.equals(tenant, nd.tenant)
+              && Objects.equals(namespace, nd.namespace)
+              && Objects.equals(key, nd.key)
+              && Objects.equals(myself, nd.myself)
+              && Objects.equals(currentValue, nd.currentValue) // it's either String or List<String>
+              && isArray == nd.isArray;
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(tenant, namespace, key, myself, currentValue, isArray);
     }
 
     /**
@@ -424,7 +428,7 @@ public final class ConfigurationChangeNotifier {
       Method method = null;
       Vector<Object> parameters = null;
       try {
-        Object latestValue = null;
+        Object latestValue;
         if (isArray) {
           latestValue = ConfigurationManager.lookup().getAsStringValues(tenant, namespace, key);
         } else {
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/main/java/org/openecomp/core/nosqldb/util/ConfigurationManager.java b/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/main/java/org/openecomp/core/nosqldb/util/ConfigurationManager.java
index 1f5e20fd0b..bde9d06ae4 100644
--- a/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/main/java/org/openecomp/core/nosqldb/util/ConfigurationManager.java
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/main/java/org/openecomp/core/nosqldb/util/ConfigurationManager.java
@@ -20,25 +20,28 @@
 
 package org.openecomp.core.nosqldb.util;
 
+import org.openecomp.core.utilities.file.FileUtils;
 import org.openecomp.sdc.logging.api.Logger;
 import org.openecomp.sdc.logging.api.LoggerFactory;
 import org.openecomp.sdc.tosca.services.YamlUtil;
 
 import java.io.FileInputStream;
-import java.io.FileNotFoundException;
+import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 
 /**
  * The type Configuration manager.
  */
 public class ConfigurationManager {
 
-  private static final String CONFIGURATION_YAML_FILE = "configuration.yaml";
-  private static final String cassandraKey = "cassandraConfig";
+  static final String CONFIGURATION_YAML_FILE = "configuration.yaml";
+
+  private static final String CASSANDRA_KEY = "cassandraConfig";
   private static final String DEFAULT_KEYSPACE_NAME = "dox";
   private static final String CASSANDRA_ADDRESSES = "cassandra.addresses";
   private static final String CASSANDRA_DOX_KEY_STORE = "cassandra.dox.keystore";
@@ -49,14 +52,14 @@ public class ConfigurationManager {
   private static final String CASSANDRA_SSL = "cassandra.ssl";
   private static final String CASSANDRA_TRUSTSTORE = "cassandra.Truststore";
   private static final String CASSANDRA_TRUSTSTORE_PASSWORD = "cassandra.TruststorePassword";
-  private static final String cassandraHostsKey = "cassandraHosts";
-  private static final String cassandraPortKey = "port";
-  private static final String cassandraUsernameKey = "username";
-  private static final String cassandraPasswordKey = "password";
-  private static final String cassandraAuthenticateKey = "authenticate";
-  private static final String cassandraSSLKey = "ssl";
-  private static final String cassandraTruststorePathKey = "truststorePath";
-  private static final String cassandraTruststorePasswordKey = "truststorePassword";
+  private static final String CASSANDRA_HOSTS_KEY = "cassandraHosts";
+  private static final String CASSANDRA_PORT_KEY = "port";
+  private static final String CASSANDRA_USERNAME_KEY = "username";
+  private static final String CASSANDRA_PASSWORD_KEY = "password";
+  private static final String CASSANDRA_AUTHENTICATE_KEY = "authenticate";
+  private static final String CASSANDRA_SSL_KEY = "ssl";
+  private static final String CASSANDRA_TRUSTSTORE_PATH_KEY = "truststorePath";
+  private static final String CASSANDRA_TRUSTSTORE_PASSWORD_KEY = "truststorePassword";
   private static ConfigurationManager instance = null;
   private final LinkedHashMap<String, Object> cassandraConfiguration;
 
@@ -64,18 +67,24 @@ public class ConfigurationManager {
 
 
   private ConfigurationManager() {
-    YamlUtil yamlUtil = new YamlUtil();
+
     String configurationYamlFile = System.getProperty(CONFIGURATION_YAML_FILE);
-    InputStream yamlAsString;
-    if (configurationYamlFile != null) {
-      yamlAsString = getConfigFileIs(configurationYamlFile);
-    } else {
-      //Load from resources
-      yamlAsString = yamlUtil.loadYamlFileIs("/" + CONFIGURATION_YAML_FILE);
-    }
-    Map<String, LinkedHashMap<String, Object>> configurationMap = yamlUtil.yamlToMap(yamlAsString);
-    cassandraConfiguration = configurationMap.get(cassandraKey);
 
+    Function<InputStream, Map<String, LinkedHashMap<String, Object>>> reader = (is) -> {
+      YamlUtil yamlUtil = new YamlUtil();
+      return yamlUtil.yamlToMap(is);
+    };
+
+    try {
+
+      Map<String, LinkedHashMap<String, Object>> configurationMap = configurationYamlFile != null
+              ? readFromFile(configurationYamlFile, reader) // load from file
+              : FileUtils.readViaInputStream(CONFIGURATION_YAML_FILE, reader); // or from resource
+      cassandraConfiguration = configurationMap.get(CASSANDRA_KEY);
+
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to read configuration", e);
+    }
   }
 
   /**
@@ -101,7 +110,7 @@ public class ConfigurationManager {
     if (addresses != null) {
       return addresses.split(",");
     }
-    List lsAddresses = (ArrayList) cassandraConfiguration.get(cassandraHostsKey);
+    List lsAddresses = (ArrayList) cassandraConfiguration.get(CASSANDRA_HOSTS_KEY);
     String[] addressesArray;
     addressesArray = (String[]) lsAddresses.toArray(new String[lsAddresses.size()]);
     return addressesArray;
@@ -131,7 +140,7 @@ public class ConfigurationManager {
   public String getUsername() {
     String username = System.getProperty(CASSANDRA_USER);
     if (username == null) {
-      username = (String) cassandraConfiguration.get(cassandraUsernameKey);
+      username = (String) cassandraConfiguration.get(CASSANDRA_USERNAME_KEY);
     }
     return username;
   }
@@ -144,7 +153,7 @@ public class ConfigurationManager {
   public String getPassword() {
     String password = System.getProperty(CASSANDRA_PASSWORD);
     if (password == null) {
-      password = (String) cassandraConfiguration.get(cassandraPasswordKey);
+      password = (String) cassandraConfiguration.get(CASSANDRA_PASSWORD_KEY);
     }
     return password;
   }
@@ -157,7 +166,7 @@ public class ConfigurationManager {
   public String getTruststorePath() {
     String truststorePath = System.getProperty(CASSANDRA_TRUSTSTORE);
     if (truststorePath == null) {
-      truststorePath = (String) cassandraConfiguration.get(cassandraTruststorePathKey);
+      truststorePath = (String) cassandraConfiguration.get(CASSANDRA_TRUSTSTORE_PATH_KEY);
     }
     return truststorePath;
   }
@@ -170,7 +179,7 @@ public class ConfigurationManager {
   public String getTruststorePassword() {
     String truststorePassword = System.getProperty(CASSANDRA_TRUSTSTORE_PASSWORD);
     if (truststorePassword == null) {
-      truststorePassword = (String) cassandraConfiguration.get(cassandraTruststorePasswordKey);
+      truststorePassword = (String) cassandraConfiguration.get(CASSANDRA_TRUSTSTORE_PASSWORD_KEY);
     }
     return truststorePassword;
   }
@@ -184,7 +193,7 @@ public class ConfigurationManager {
     int port;
     String sslPort = System.getProperty(CASSANDRA_PORT);
     if (sslPort == null) {
-      sslPort = (String) cassandraConfiguration.get(cassandraPortKey);
+      sslPort = (String) cassandraConfiguration.get(CASSANDRA_PORT_KEY);
       if (sslPort == null) {
         sslPort = "0";
       }
@@ -200,7 +209,7 @@ public class ConfigurationManager {
    * @return the boolean
    */
   public boolean isSsl() {
-    return getBooleanResult(CASSANDRA_SSL, cassandraSSLKey);
+    return getBooleanResult(CASSANDRA_SSL, CASSANDRA_SSL_KEY);
   }
 
   /**
@@ -209,7 +218,7 @@ public class ConfigurationManager {
    * @return the boolean
    */
   public boolean isAuthenticate() {
-    return getBooleanResult(CASSANDRA_AUTHENTICATE, cassandraAuthenticateKey);
+    return getBooleanResult(CASSANDRA_AUTHENTICATE, CASSANDRA_AUTHENTICATE_KEY);
   }
 
   private Boolean getBooleanResult(String property, String key) {
@@ -226,13 +235,9 @@ public class ConfigurationManager {
     return res;
   }
 
-  private InputStream getConfigFileIs(String file) {
-    InputStream is = null;
-    try {
-      is = new FileInputStream(file);
-    } catch (FileNotFoundException exception) {
-      log.debug("",exception);
+  private <T> T readFromFile(String file, Function<InputStream, T> reader) throws IOException {
+    try (InputStream is = new FileInputStream(file)) {
+      return reader.apply(is);
     }
-    return is;
   }
 }
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/test/java/org/openecomp/core/nosqldb/util/ConfigurationManagerTest.java b/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/test/java/org/openecomp/core/nosqldb/util/ConfigurationManagerTest.java
new file mode 100644
index 0000000000..f8d5d2dce7
--- /dev/null
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-nosqldb-lib/openecomp-nosqldb-core/src/test/java/org/openecomp/core/nosqldb/util/ConfigurationManagerTest.java
@@ -0,0 +1,73 @@
+package org.openecomp.core.nosqldb.util;
+
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.lang.reflect.Field;
+
+import static org.testng.Assert.*;
+
+/**
+ * @author EVITALIY
+ * @since 22 Oct 17
+ */
+public class ConfigurationManagerTest {
+
+    private static final String NON_EXISTENT = "unexistentfile";
+
+    @BeforeMethod
+    public void resetInstance() throws NoSuchFieldException, IllegalAccessException {
+        Field field = ConfigurationManager.class.getDeclaredField("instance");
+        field.setAccessible(true);
+        field.set(null, null);
+    }
+
+    @Test(expectedExceptions = IOException.class,
+            expectedExceptionsMessageRegExp = ".*" + NON_EXISTENT + ".*")
+    public void testGetInstanceSystemProperty() throws Throwable {
+
+        try (ConfigurationSystemPropertyUpdater updater = new ConfigurationSystemPropertyUpdater(NON_EXISTENT)) {
+            ConfigurationManager.getInstance();
+        } catch (RuntimeException e) {
+            Throwable cause = e.getCause();
+            throw cause == null ? e : cause;
+        }
+    }
+
+    @Test()
+    public void testGetInstanceDefault() throws Exception {
+
+        try (ConfigurationSystemPropertyUpdater property = new ConfigurationSystemPropertyUpdater()) {
+            ConfigurationManager manager = ConfigurationManager.getInstance();
+            assertNotNull(manager.getUsername());
+        }
+    }
+
+
+    private static class ConfigurationSystemPropertyUpdater implements Closeable {
+
+        private final String oldValue;
+
+        private ConfigurationSystemPropertyUpdater(String value) {
+            this.oldValue = System.getProperty(ConfigurationManager.CONFIGURATION_YAML_FILE);
+            System.setProperty(ConfigurationManager.CONFIGURATION_YAML_FILE, value);
+        }
+
+        private ConfigurationSystemPropertyUpdater() {
+            this.oldValue = System.getProperty(ConfigurationManager.CONFIGURATION_YAML_FILE);
+            System.clearProperty(ConfigurationManager.CONFIGURATION_YAML_FILE);
+        }
+
+        @Override
+        public void close() throws IOException {
+
+            if (oldValue == null) {
+                System.clearProperty(ConfigurationManager.CONFIGURATION_YAML_FILE);
+            } else {
+                System.setProperty(ConfigurationManager.CONFIGURATION_YAML_FILE, oldValue);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/main/java/org/openecomp/core/utilities/file/FileUtils.java b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/main/java/org/openecomp/core/utilities/file/FileUtils.java
index 6ff213c34c..6ab3f8b049 100644
--- a/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/main/java/org/openecomp/core/utilities/file/FileUtils.java
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/main/java/org/openecomp/core/utilities/file/FileUtils.java
@@ -28,6 +28,7 @@ import org.openecomp.sdc.logging.api.LoggerFactory;
 import org.openecomp.sdc.tosca.services.YamlUtil;
 
 import java.io.ByteArrayInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
@@ -54,7 +55,16 @@ public class FileUtils {
    * @param function logic to be applied to the input stream
    */
   public static <T> T readViaInputStream(String fileName, Function<InputStream, T> function) {
-    return readViaInputStream(FileUtils.class.getClassLoader().getResource(fileName), function);
+
+    Objects.requireNonNull(fileName);
+
+    // the leading slash doesn't make sense and doesn't work when used with a class loader
+    URL resource = FileUtils.class.getClassLoader().getResource(fileName.startsWith("/") ? fileName.substring(1) : fileName);
+    if (resource == null) {
+      throw new IllegalArgumentException("Resource not found: " + fileName);
+    }
+
+    return readViaInputStream(resource, function);
   }
 
   /**
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/java/org/openecomp/core/utilities/file/FileUtilsTest.java b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/java/org/openecomp/core/utilities/file/FileUtilsTest.java
new file mode 100644
index 0000000000..e32aa39904
--- /dev/null
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/java/org/openecomp/core/utilities/file/FileUtilsTest.java
@@ -0,0 +1,48 @@
+package org.openecomp.core.utilities.file;
+
+import org.testng.annotations.Test;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.function.Function;
+
+import static org.testng.Assert.assertTrue;
+
+/**
+ * @author EVITALIY
+ * @since 22 Oct 17
+ */
+public class FileUtilsTest {
+
+    private static final String TEST_RESOURCE = FileUtilsTest.class.getPackage().getName()
+            .replace('.', '/') + "/test-resource.txt";
+
+    private static final Function<InputStream, Integer> TEST_FUNCTION = (s) -> {
+
+        try {
+            return s.available();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    };
+
+    @Test
+    public void testReadViaInputStreamWithSlash() throws Exception {
+        assertTrue(FileUtils.readViaInputStream(TEST_RESOURCE, TEST_FUNCTION) > 0);
+    }
+
+    @Test
+    public void testReadViaInputStreamWithoutSlash() throws Exception {
+        assertTrue(FileUtils.readViaInputStream(TEST_RESOURCE, TEST_FUNCTION) > 0);
+    }
+
+    @Test(expectedExceptions = NullPointerException.class)
+    public void testReadViaInputStreamNull() throws Exception {
+        FileUtils.readViaInputStream((String) null, TEST_FUNCTION);
+    }
+
+    @Test(expectedExceptions = IllegalArgumentException.class)
+    public void testReadViaInputStreamNotFound() throws Exception {
+        FileUtils.readViaInputStream("notfound.txt", TEST_FUNCTION);
+    }
+}
\ No newline at end of file
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/resources/org/openecomp/core/utilities/file/test-resource.txt b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/resources/org/openecomp/core/utilities/file/test-resource.txt
new file mode 100644
index 0000000000..dce400c8a5
--- /dev/null
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-utilities-lib/src/test/resources/org/openecomp/core/utilities/file/test-resource.txt
@@ -0,0 +1 @@
+CLASSPATH RESOURCE
\ No newline at end of file
diff --git a/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/services/heattotosca/HeatToToscaUtil.java b/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/services/heattotosca/HeatToToscaUtil.java
index c1f69cf3bf..4e1a60fff8 100644
--- a/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/services/heattotosca/HeatToToscaUtil.java
+++ b/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/services/heattotosca/HeatToToscaUtil.java
@@ -119,9 +119,12 @@ public class HeatToToscaUtil {
     mdcDataDebugMessage.debugEntryMessage(null, null);
     HeatToToscaTranslator heatToToscaTranslator =
         HeatToToscaTranslatorFactory.getInstance().createInterface();
-    InputStream fileContent = fileNameContentMap.getFileContent(SdcCommon.MANIFEST_NAME);
 
-    heatToToscaTranslator.addManifest(SdcCommon.MANIFEST_NAME, FileUtils.toByteArray(fileContent));
+    try (InputStream fileContent = fileNameContentMap.getFileContent(SdcCommon.MANIFEST_NAME)) {
+      heatToToscaTranslator.addManifest(SdcCommon.MANIFEST_NAME, FileUtils.toByteArray(fileContent));
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to read manifest", e);
+    }
 
     fileNameContentMap.getFileList().stream()
         .filter(fileName -> !(fileName.equals(SdcCommon.MANIFEST_NAME))).forEach(
@@ -143,7 +146,7 @@ public class HeatToToscaUtil {
       return heatToToscaTranslator.translate();
     } catch (IOException e) {
       // rethrow as a RuntimeException to keep the signature backward compatible
-      throw new RuntimeException(e);
+      throw new RuntimeException("Failed to read Heat template tree", e);
     }
   }
 
diff --git a/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/utils/ResourceWalker.java b/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/utils/ResourceWalker.java
index 353b791a1f..9ff1ff9992 100644
--- a/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/utils/ResourceWalker.java
+++ b/openecomp-be/lib/openecomp-sdc-translator-lib/openecomp-sdc-translator-core/src/main/java/org/openecomp/sdc/translator/utils/ResourceWalker.java
@@ -40,8 +40,7 @@ public class ResourceWalker {
       Exception {
     Map<String, String> filesContent = new HashMap<>();
     traverse(resourceDirectoryToStart, (fileName, stream) -> {
-      BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
-      try {
+      try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) {
         filesContent.put(fileName, IOUtils.toString(reader));
       } catch (IOException exception) {
         MdcDataErrorMessage.createErrorMessageAndUpdateMdc(LoggerConstants.TARGET_ENTITY_API,
diff --git a/openecomp-be/lib/openecomp-sdc-validation-lib/openecomp-sdc-validation-sdk/src/main/java/org/openecomp/sdc/validation/util/ValidationTestUtil.java b/openecomp-be/lib/openecomp-sdc-validation-lib/openecomp-sdc-validation-sdk/src/main/java/org/openecomp/sdc/validation/util/ValidationTestUtil.java
index fa1946f987..2b58a30e50 100644
--- a/openecomp-be/lib/openecomp-sdc-validation-lib/openecomp-sdc-validation-sdk/src/main/java/org/openecomp/sdc/validation/util/ValidationTestUtil.java
+++ b/openecomp-be/lib/openecomp-sdc-validation-lib/openecomp-sdc-validation-sdk/src/main/java/org/openecomp/sdc/validation/util/ValidationTestUtil.java
@@ -25,6 +25,7 @@ import org.testng.Assert;
 
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.net.URL;
@@ -55,8 +56,6 @@ public class ValidationTestUtil {
 
   private static Map<String, byte[]> getContentMapByPath(String path) {
     Map<String, byte[]> contentMap = new HashMap<>();
-    byte[] fileContent;
-    FileInputStream fis;
     URL url = ValidationTestUtil.class.getResource(path);
     File pathFile = new File(url.getFile());
     File[] files;
@@ -71,13 +70,13 @@ public class ValidationTestUtil {
     }
 
     for (File file : files) {
-      try {
-        fis = new FileInputStream(file);
-        fileContent = FileUtils.toByteArray(fis);
-        contentMap.put(file.getName(), fileContent);
+
+      try (FileInputStream fis = new FileInputStream(file)) {
+        contentMap.put(file.getName(), FileUtils.toByteArray(fis));
       } catch (IOException e) {
-        log.debug("",e);
+        throw new RuntimeException("Failed to read file: " + file, e);
       }
+
     }
     return contentMap;
   }