[java] Add nullness for logging (SeleniumHQ#15108)

Co-authored-by: Viet Nguyen Duc <[email protected]>

Author: mk868

java/src/org/openqa/selenium/logging/LogEntries.java

@@ -23,13 +23,15 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.stream.StreamSupport;
+import org.jspecify.annotations.NullMarked;
 import org.openqa.selenium.Beta;
 
 /**
  * Represent a pool of {@link LogEntry}. This class also provides filtering mechanisms based on
  * levels.
  */
 @Beta
+@NullMarked
 public class LogEntries implements Iterable<LogEntry> {
 
   private final List<LogEntry> entries;

java/src/org/openqa/selenium/logging/LogEntry.java

@@ -22,8 +22,10 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.logging.Level;
+import org.jspecify.annotations.NullMarked;
 
 /** Represents a single log statement. */
+@NullMarked
 public class LogEntry {
 
   private final Level level;

java/src/org/openqa/selenium/logging/LogLevelMapping.java

@@ -20,13 +20,20 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import java.util.logging.Level;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class LogLevelMapping {
 
   /** WebDriver log level DEBUG which is mapped to Level.FINE. */
   private static final String DEBUG = "DEBUG";
 
+  // Default the log level to info.
+  private static final Level DEFAULT_LEVEL = Level.INFO;
+
   private static final Map<Integer, Level> levelMap;
 
   static {
@@ -70,15 +77,15 @@ public static String getName(Level level) {
     return normalized == Level.FINE ? DEBUG : normalized.getName();
   }
 
-  public static Level toLevel(String logLevelName) {
+  public static Level toLevel(@Nullable String logLevelName) {
     if (logLevelName == null || logLevelName.isEmpty()) {
-      // Default the log level to info.
-      return Level.INFO;
+      return DEFAULT_LEVEL;
     }
 
     if (logLevelName.equals(DEBUG)) {
       return Level.FINE;
     }
-    return levelMap.get(Level.parse(logLevelName).intValue());
+    return Optional.ofNullable(levelMap.get(Level.parse(logLevelName).intValue()))
+        .orElse(DEFAULT_LEVEL);
   }
 }

java/src/org/openqa/selenium/logging/SessionLogs.java

@@ -24,10 +24,13 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.jspecify.annotations.NullMarked;
 import org.openqa.selenium.Beta;
+import org.openqa.selenium.internal.Require;
 
 /** Contains the logs for a session divided by supported log types. */
 @Beta
+@NullMarked
 public class SessionLogs {
   private final Map<String, LogEntries> logTypeToEntriesMap;
 
@@ -66,7 +69,7 @@ public static SessionLogs fromJSON(Map<String, Object> rawSessionLogs) {
         logEntries.add(
             new LogEntry(
                 LogLevelMapping.toLevel(String.valueOf(rawEntry.get("level"))),
-                ((Number) rawEntry.get("timestamp")).longValue(),
+                Require.nonNull("timestamp", (Number) rawEntry.get("timestamp")).longValue(),
                 String.valueOf(rawEntry.get("message"))));
       }
       sessionLogs.addLog(logType, new LogEntries(logEntries));

java/test/org/openqa/selenium/logging/LoggingTest.java

@@ -40,6 +40,7 @@ void testLogLevelConversions() {
     assertThat(toLevel("WARNING")).isEqualTo(WARNING);
     assertThat(toLevel("SEVERE")).isEqualTo(SEVERE);
     assertThat(toLevel("OFF")).isEqualTo(OFF);
+    assertThat(toLevel(null)).isEqualTo(INFO);
   }
 
   @Test