[java] Add nullness for enums (SeleniumHQ#15105)

Co-authored-by: Viet Nguyen Duc <nguyenducviet4496@gmail.com>

Author: 2 people

java/src/org/openqa/selenium/PageLoadStrategy.java

@@ -17,6 +17,10 @@
 
 package org.openqa.selenium;
 
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
 public enum PageLoadStrategy {
   NONE("none"),
   EAGER("eager"),
@@ -33,7 +37,7 @@ public String toString() {
     return String.valueOf(text);
   }
 
-  public static PageLoadStrategy fromString(String text) {
+  public static @Nullable PageLoadStrategy fromString(@Nullable String text) {
     if (text != null) {
       for (PageLoadStrategy b : PageLoadStrategy.values()) {
         if (text.equalsIgnoreCase(b.text)) {

java/src/org/openqa/selenium/UnexpectedAlertBehaviour.java

@@ -17,6 +17,10 @@
 
 package org.openqa.selenium;
 
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
 public enum UnexpectedAlertBehaviour {
   ACCEPT("accept"),
   DISMISS("dismiss"),
@@ -35,7 +39,7 @@ public String toString() {
     return String.valueOf(text);
   }
 
-  public static UnexpectedAlertBehaviour fromString(String text) {
+  public static @Nullable UnexpectedAlertBehaviour fromString(@Nullable String text) {
     if (text != null) {
       for (UnexpectedAlertBehaviour b : UnexpectedAlertBehaviour.values()) {
         if (text.equalsIgnoreCase(b.text)) {

java/src/org/openqa/selenium/WindowType.java

@@ -17,7 +17,11 @@
 
 package org.openqa.selenium;
 
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
 /** Represents the type of new browser window that may be created. */
+@NullMarked
 public enum WindowType {
   WINDOW("window"),
   TAB("tab"),
@@ -34,7 +38,7 @@ public String toString() {
     return String.valueOf(text);
   }
 
-  public static WindowType fromString(String text) {
+  public static @Nullable WindowType fromString(@Nullable String text) {
     if (text != null) {
       for (WindowType b : WindowType.values()) {
         if (text.equalsIgnoreCase(b.text)) {