BAEL-4656: Get available port number for the test (#10096)

libraries-5/src/test/java/com/baeldung/pact/PactConsumerDrivenContractUnitTest.java

@@ -7,22 +7,38 @@ import au.com.dius.pact.consumer.dsl.PactDslWithProvider;
 import au.com.dius.pact.model.RequestResponsePact;
 import org.junit.Rule;
 import org.junit.Test;
-import org.springframework.http.HttpEntity;
+import org.springframework.http.*;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
-import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.RestTemplate;
 
+import java.io.IOException;
+import java.net.ServerSocket;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Random;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class PactConsumerDrivenContractUnitTest {
 
+    private static int getAvailablePort() {
+        return new Random()
+            .ints(6000, 9000)
+            .filter(PactConsumerDrivenContractUnitTest::isFree)
+            .findFirst()
+            .orElse(8080);
+    }
+
+    private static boolean isFree(int port) {
+        try {
+            new ServerSocket(port).close();
+            return true;
+        } catch (IOException e) {
+            return false;
+        }
+    }
+
     @Rule
-    public PactProviderRuleMk2 mockProvider = new PactProviderRuleMk2("test_provider", "localhost", 8080, this);
+    public PactProviderRuleMk2 mockProvider = new PactProviderRuleMk2("test_provider", "localhost", getAvailablePort(), this);
 
     @Pact(consumer = "test_consumer")
     public RequestResponsePact createPact(PactDslWithProvider builder) {