Bael 4461 3 (#4557)

* [BAEL-4462] - Fixed integration tests

* [BAEL-7055] - Fix JUNIT in core java module

core-java/src/test/java/com/baeldung/socket/EchoIntegrationTest.java

@@ -1,21 +1,29 @@
 package com.baeldung.socket;
 
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.util.concurrent.Executors;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
-import java.util.concurrent.Executors;
-
-import static org.junit.Assert.assertEquals;
-
 public class EchoIntegrationTest {
-    private static final Integer PORT = 4444;
+    private static int port;
 
     @BeforeClass
-    public static void start() throws InterruptedException {
+    public static void start() throws InterruptedException, IOException {
+        
+        // Take an available port
+        ServerSocket s = new ServerSocket(0);
+        port = s.getLocalPort();
+        s.close();
+
         Executors.newSingleThreadExecutor()
-            .submit(() -> new EchoServer().start(PORT));
+            .submit(() -> new EchoServer().start(port));
         Thread.sleep(500);
     }
 
@@ -23,7 +31,7 @@ public class EchoIntegrationTest {
 
     @Before
     public void init() {
-        client.startConnection("127.0.0.1", PORT);
+        client.startConnection("127.0.0.1", port);
     }
 
     @After

core-java/src/test/java/com/baeldung/socket/GreetServerIntegrationTest.java

@@ -1,31 +1,39 @@
 package com.baeldung.socket;
 
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.util.concurrent.Executors;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
-import java.util.concurrent.Executors;
-
-import static org.junit.Assert.assertEquals;
-
 public class GreetServerIntegrationTest {
 
     private GreetClient client;
 
-    private static final Integer PORT = 6666;
+    private static int port;
 
     @BeforeClass
-    public static void start() throws InterruptedException {
+    public static void start() throws InterruptedException, IOException {
+        
+        // Take an available port
+        ServerSocket s = new ServerSocket(0);
+        port = s.getLocalPort();
+        s.close();
+        
         Executors.newSingleThreadExecutor()
-            .submit(() -> new GreetServer().start(PORT));
+            .submit(() -> new GreetServer().start(port));
         Thread.sleep(500);
     }
 
     @Before
     public void init() {
         client = new GreetClient();
-        client.startConnection("127.0.0.1", PORT);
+        client.startConnection("127.0.0.1", port);
 
     }
 

core-java/src/test/java/com/baeldung/socket/SocketEchoMultiIntegrationTest.java

@@ -1,26 +1,35 @@
 package com.baeldung.socket;
 
 import org.junit.BeforeClass;
+import org.junit.Ignore;
 import org.junit.Test;
 
+import java.io.IOException;
+import java.net.ServerSocket;
 import java.util.concurrent.Executors;
 
 import static org.junit.Assert.assertEquals;
 
 public class SocketEchoMultiIntegrationTest {
 
-    private static final Integer PORT = 5555;
+    private static int port;
 
     @BeforeClass
-    public static void start() throws InterruptedException {
-        Executors.newSingleThreadExecutor().submit(() -> new EchoMultiServer().start(PORT));
+    public static void start() throws InterruptedException, IOException {
+
+        // Take an available port
+        ServerSocket s = new ServerSocket(0);
+        port = s.getLocalPort();
+        s.close();
+
+        Executors.newSingleThreadExecutor().submit(() -> new EchoMultiServer().start(port));
         Thread.sleep(500);
     }
 
     @Test
     public void givenClient1_whenServerResponds_thenCorrect() {
         EchoClient client = new EchoClient();
-        client.startConnection("127.0.0.1", PORT);
+        client.startConnection("127.0.0.1", port);
         String msg1 = client.sendMessage("hello");
         String msg2 = client.sendMessage("world");
         String terminate = client.sendMessage(".");
@@ -34,7 +43,7 @@ public class SocketEchoMultiIntegrationTest {
     @Test
     public void givenClient2_whenServerResponds_thenCorrect() {
         EchoClient client = new EchoClient();
-        client.startConnection("127.0.0.1", PORT);
+        client.startConnection("127.0.0.1", port);
         String msg1 = client.sendMessage("hello");
         String msg2 = client.sendMessage("world");
         String terminate = client.sendMessage(".");
@@ -47,7 +56,7 @@ public class SocketEchoMultiIntegrationTest {
     @Test
     public void givenClient3_whenServerResponds_thenCorrect() {
         EchoClient client = new EchoClient();
-        client.startConnection("127.0.0.1", PORT);
+        client.startConnection("127.0.0.1", port);
         String msg1 = client.sendMessage("hello");
         String msg2 = client.sendMessage("world");
         String terminate = client.sendMessage(".");