Polish SerializationTestUtils, clean up warnings, etc.

spring-core/src/test/java/org/springframework/util/SocketUtilsTests.java

@@ -75,10 +75,10 @@ class SocketUtilsTests {
 	}
 
 	@Test
-	@SuppressWarnings("try")
 	void findAvailableTcpPortWhenPortOnLoopbackInterfaceIsNotAvailable() throws Exception {
 		int port = SocketUtils.findAvailableTcpPort();
 		try (ServerSocket socket = ServerSocketFactory.getDefault().createServerSocket(port, 1, InetAddress.getByName("localhost"))) {
+			assertThat(socket).isNotNull();
 			// will only look for the exact port
 			assertThatIllegalStateException().isThrownBy(() ->
 					SocketUtils.findAvailableTcpPort(port, port))
@@ -149,10 +149,10 @@ class SocketUtilsTests {
 	}
 
 	@Test
-	@SuppressWarnings("try")
 	void findAvailableUdpPortWhenPortOnLoopbackInterfaceIsNotAvailable() throws Exception {
 		int port = SocketUtils.findAvailableUdpPort();
 		try (DatagramSocket socket = new DatagramSocket(port, InetAddress.getByName("localhost"))) {
+			assertThat(socket).isNotNull();
 			// will only look for the exact port
 			assertThatIllegalStateException().isThrownBy(() ->
 					SocketUtils.findAvailableUdpPort(port, port))

spring-core/src/testFixtures/java/org/springframework/core/testfixture/io/SerializationTestUtils.java

@@ -26,9 +26,11 @@ import java.io.OutputStream;
 
 /**
  * Utilities for testing serializability of objects.
- * Exposes static methods for use in other test cases.
+ *
+ * <p>Exposes static methods for use in other test cases.
  *
  * @author Rod Johnson
+ * @author Sam Brannen
  */
 public class SerializationTestUtils {
 
@@ -49,7 +51,8 @@ public class SerializationTestUtils {
 		}
 	}
 
-	public static Object serializeAndDeserialize(Object o) throws IOException, ClassNotFoundException {
+	@SuppressWarnings("unchecked")
+	public static <T> T serializeAndDeserialize(T o) throws IOException, ClassNotFoundException {
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
 		try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
 			oos.writeObject(o);
@@ -59,7 +62,21 @@ public class SerializationTestUtils {
 
 		ByteArrayInputStream is = new ByteArrayInputStream(bytes);
 		try (ObjectInputStream ois = new ObjectInputStream(is)) {
-			return ois.readObject();
+			return (T) ois.readObject();
+		}
+	}
+
+	public static <T> T serializeAndDeserialize(Object o, Class<T> expectedType) throws IOException, ClassNotFoundException {
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
+			oos.writeObject(o);
+			oos.flush();
+		}
+		byte[] bytes = baos.toByteArray();
+
+		ByteArrayInputStream is = new ByteArrayInputStream(bytes);
+		try (ObjectInputStream ois = new ObjectInputStream(is)) {
+			return expectedType.cast(ois.readObject());
 		}
 	}