fixed network interface tetst (#797)

* made changes to java reflection

* removed redundant method makeSound in Animal abstract class

* added project for play-framework article

* added project for regex

* changed regex project from own model to core-java

* added project for routing in play

* made changes to regex project

* refactored code for REST API with Play project

* refactored student store indexing to zero base

* added unit tests, removed bad names

* added NIO Selector project under core-java module

* requested changes made

* added project for nio2

* standardized exception based tests

* fixed exception based tests

* removed redundant files

* added network interface project

* used UUID other than timestamps

* fixed network interface tests

* removed filetest change

core-java/src/test/java/com/baeldung/java/networking/interfaces/NetworkInterfaceTest.java

@@ -1,8 +1,6 @@
 package com.baeldung.java.networking.interfaces;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.*;
 
 import java.net.InetAddress;
 import java.net.InterfaceAddress;
@@ -18,44 +16,44 @@ public class NetworkInterfaceTest {
     @Test
     public void givenName_whenReturnsNetworkInterface_thenCorrect() throws SocketException {
         NetworkInterface nif = NetworkInterface.getByName("lo");
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
     public void givenInExistentName_whenReturnsNull_thenCorrect() throws SocketException {
         NetworkInterface nif = NetworkInterface.getByName("inexistent_name");
-        assertTrue(nif == null);
+        assertNull(nif);
     }
 
     @Test
     public void givenIP_whenReturnsNetworkInterface_thenCorrect() throws SocketException, UnknownHostException {
         byte[] ip = new byte[] { 127, 0, 0, 1 };
         NetworkInterface nif = NetworkInterface.getByInetAddress(InetAddress.getByAddress(ip));
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
     public void givenHostName_whenReturnsNetworkInterface_thenCorrect() throws SocketException, UnknownHostException {
         NetworkInterface nif = NetworkInterface.getByInetAddress(InetAddress.getByName("localhost"));
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
     public void givenLocalHost_whenReturnsNetworkInterface_thenCorrect() throws SocketException, UnknownHostException {
         NetworkInterface nif = NetworkInterface.getByInetAddress(InetAddress.getLocalHost());
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
     public void givenLoopBack_whenReturnsNetworkInterface_thenCorrect() throws SocketException, UnknownHostException {
         NetworkInterface nif = NetworkInterface.getByInetAddress(InetAddress.getLoopbackAddress());
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
     public void givenIndex_whenReturnsNetworkInterface_thenCorrect() throws SocketException, UnknownHostException {
         NetworkInterface nif = NetworkInterface.getByIndex(0);
-        assertFalse(nif == null);
+        assertNotNull(nif);
     }
 
     @Test
@@ -112,12 +110,13 @@ public class NetworkInterfaceTest {
     public void givenInterface_whenGetsMacAddress_thenCorrect() throws SocketException, UnknownHostException {
         NetworkInterface nif = NetworkInterface.getByName("lo");
         byte[] bytes = nif.getHardwareAddress();
-        assertFalse(bytes == null);
+        assertNotNull(bytes);
     }
 
     @Test
     public void givenInterface_whenGetsMTU_thenCorrect() throws SocketException, UnknownHostException {
-        NetworkInterface nif = NetworkInterface.getByName("lo");
+        NetworkInterface nif = NetworkInterface.getByName("net0");
         int mtu = nif.getMTU();
+        assertEquals(1500, mtu);
     }
 }

core-java/src/test/java/com/baeldung/java/nio2/FileTest.java

@@ -1,14 +1,20 @@
 package com.baeldung.java.nio2;
 
-import org.junit.Test;
-
-import java.io.IOException;
-import java.nio.file.*;
-import java.util.UUID;
-
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.io.IOException;
+import java.nio.file.DirectoryNotEmptyException;
+import java.nio.file.FileAlreadyExistsException;
+import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import java.util.UUID;
+
+import org.junit.Test;
+
 public class FileTest {
     private static final String HOME = System.getProperty("user.home");
 
@@ -155,7 +161,6 @@ public class FileTest {
     @Test(expected = NoSuchFileException.class)
     public void givenInexistentFile_whenDeleteFails_thenCorrect() throws IOException {
         Path p = Paths.get(HOME + "/inexistentFile.txt");
-        assertFalse(Files.exists(p));
         Files.delete(p);
     }