[java] JSpecify annotations for org.openqa.selenium.net (#16463)

Co-authored-by: Diego Molina <diemol@users.noreply.github.com>

Author: mk868

java/src/org/openqa/selenium/net/LinuxEphemeralPortRangeDetector.java

@@ -25,7 +25,9 @@
 import java.io.UncheckedIOException;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public class LinuxEphemeralPortRangeDetector implements EphemeralPortRangeDetector {
 
  private final int firstEphemeralPort;

java/src/org/openqa/selenium/net/NetworkUtils.java

@@ -28,17 +28,21 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Platform;
 import org.openqa.selenium.WebDriverException;
+import org.openqa.selenium.internal.Require;
 
+@NullMarked
 public class NetworkUtils {
 
- private static InetAddress cachedIp4NonLoopbackAddressOfThisMachine;
- private static String cachedIp4NonLoopbackAddressHostName;
+ private static @Nullable InetAddress cachedIp4NonLoopbackAddressOfThisMachine;
+ private static @Nullable String cachedIp4NonLoopbackAddressHostName;
 
  private final NetworkInterfaceProvider networkInterfaceProvider;
- private volatile String hostname;
- private volatile String address;
+ private volatile @Nullable String hostname;
+ private volatile @Nullable String address;
 
  NetworkUtils(NetworkInterfaceProvider networkInterfaceProvider) {
  this.networkInterfaceProvider = networkInterfaceProvider;
@@ -56,13 +60,13 @@ public NetworkUtils() {
  public String getHostname() {
  determineHostnameAndAddress();
 
- return hostname;
+ return Require.nonNull("Hostname", hostname);
  }
 
  public String getHostAddress() {
  determineHostnameAndAddress();
 
- return address;
+ return Require.nonNull("Address", address);
  }
 
  public String getPrivateLocalAddress() {
@@ -81,7 +85,7 @@ public String getPrivateLocalAddress() {
  *
  * @return A String representing the host name or non-loopback IP4 address of this machine.
  */
- public String getNonLoopbackAddressOfThisMachine() {
+ public @Nullable String getNonLoopbackAddressOfThisMachine() {
  InetAddress ip4NonLoopbackAddressOfThisMachine = getIp4NonLoopbackAddressOfThisMachine();
  if (!Objects.equals(
  cachedIp4NonLoopbackAddressOfThisMachine, ip4NonLoopbackAddressOfThisMachine)) {
@@ -113,10 +117,13 @@ public InetAddress getIp4NonLoopbackAddressOfThisMachine() {
  *
  * @return The address part og such an address
  */
- public String obtainLoopbackIp4Address() {
+ public @Nullable String obtainLoopbackIp4Address() {
  final NetworkInterface networkInterface = getLoopBackAndIp4Only();
  if (networkInterface != null) {
- return networkInterface.getIp4LoopbackOnly().getHostName();
+ InetAddress loopback = networkInterface.getIp4LoopbackOnly();
+ if (loopback != null) {
+ return loopback.getHostName();
+ }
  }
 
  final String ipOfIp4LoopBack = getIpOfLoopBackIp4();
@@ -156,7 +163,7 @@ private InetAddress grabFirstNetworkAddress() {
  return firstAddress;
  }
 
- public String getIpOfLoopBackIp4() {
+ public @Nullable String getIpOfLoopBackIp4() {
  for (NetworkInterface iface : networkInterfaceProvider.getNetworkInterfaces()) {
  final InetAddress netAddress = iface.getIp4LoopbackOnly();
  if (netAddress != null) {
@@ -166,7 +173,7 @@ public String getIpOfLoopBackIp4() {
  return null;
  }
 
- private NetworkInterface getLoopBackAndIp4Only() {
+ private @Nullable NetworkInterface getLoopBackAndIp4Only() {
  for (NetworkInterface iface : networkInterfaceProvider.getNetworkInterfaces()) {
  if (iface.isIp4AddressBindingOnly() && iface.isLoopBack()) {
  return iface;

java/src/org/openqa/selenium/net/PortProber.java

@@ -26,8 +26,10 @@
 import java.net.SocketTimeoutException;
 import java.util.Random;
 import java.util.concurrent.TimeUnit;
+import org.jspecify.annotations.NullMarked;
 import org.openqa.selenium.Platform;
 
+@NullMarked
 public class PortProber {
 
  public static final int HIGHEST_PORT = 65535;

java/src/org/openqa/selenium/net/UrlChecker.java

@@ -31,8 +31,10 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Logger;
+import org.jspecify.annotations.NullMarked;
 
 /** Polls a URL until a HTTP 200 response is received. */
+@NullMarked
 public class UrlChecker {
 
  private static final Logger LOG = Logger.getLogger(UrlChecker.class.getName());

java/src/org/openqa/selenium/net/Urls.java

@@ -25,8 +25,10 @@
 import java.net.URL;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import org.jspecify.annotations.NullMarked;
 import org.openqa.selenium.internal.Require;
 
+@NullMarked
 public class Urls {
 
  private Urls() {