Add emit overload with no payload

api/events/src/main/java/io/opentelemetry/api/events/DefaultEventEmitter.java

@@ -22,6 +22,9 @@ static EventEmitter getInstance() {
     return INSTANCE;
   }
 
+  @Override
+  public void emit(String eventName) {}
+
   @Override
   public void emit(String eventName, AnyValue<?> payload) {}
 

api/events/src/main/java/io/opentelemetry/api/events/EventEmitter.java

@@ -33,6 +33,14 @@
 @ThreadSafe
 public interface EventEmitter {
 
+  /**
+   * Emit an event.
+   *
+   * @param eventName the event name, which defines the class or type of event. Events names SHOULD
+   *     include a namespace to avoid collisions with other event names.
+   */
+  void emit(String eventName);
+
   /**
    * Emit an event.
    *
@@ -46,6 +54,9 @@ public interface EventEmitter {
   /**
    * Emit an event.
    *
+   * <p>This is equivalent to calling {@link #emit(String, AnyValue)} with a {@link
+   * AnyValue#of(Map)} payload.
+   *
    * @param eventName the event name, which defines the class or type of event. Events names SHOULD
    *     include a namespace to avoid collisions with other event names.
    * @param payload the eventPayload, which is expected to match the schema of other events with the

api/events/src/test/java/io/opentelemetry/api/events/DefaultEventEmitterTest.java

@@ -20,6 +20,9 @@ class DefaultEventEmitterTest {
 
   @Test
   void emit() {
+    assertThatCode(() -> DefaultEventEmitter.getInstance().emit("namespace.event-name"))
+        .doesNotThrowAnyException();
+
     assertThatCode(
             () ->
                 DefaultEventEmitter.getInstance()

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProvider.java

@@ -20,6 +20,7 @@
 import io.opentelemetry.extension.incubator.logs.ExtendedLogRecordBuilder;
 import io.opentelemetry.sdk.common.Clock;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 
 /**
  * SDK implementation for {@link EventEmitterProvider}.
@@ -89,6 +90,8 @@ public EventEmitter build() {
 
   private static class SdkEventEmitter implements EventEmitter {
 
+    private static final Severity DEFAULT_SEVERITY = Severity.INFO;
+
     private final Clock clock;
     private final Logger delegateLogger;
 
@@ -103,21 +106,33 @@ public EventBuilder builder(String eventName) {
           clock,
           delegateLogger
               .logRecordBuilder()
-              .setSeverity(Severity.INFO)
+              .setSeverity(DEFAULT_SEVERITY)
               .setContext(Context.current()),
           eventName);
     }
 
+    @Override
+    public void emit(String eventName) {
+      emitInternal(eventName, null);
+    }
+
     @Override
     public void emit(String eventName, AnyValue<?> payload) {
+      emitInternal(eventName, payload);
+    }
+
+    private void emitInternal(String eventName, @Nullable AnyValue<?> payload) {
       long now = clock.now();
-      LogRecordBuilder logRecordBuilder =
-          ((ExtendedLogRecordBuilder) delegateLogger.logRecordBuilder())
-              .setBody(payload)
-              .setSeverity(Severity.INFO)
-              .setContext(Context.current())
-              .setTimestamp(now, TimeUnit.NANOSECONDS)
-              .setObservedTimestamp(now, TimeUnit.NANOSECONDS);
+      ExtendedLogRecordBuilder logRecordBuilder =
+          ((ExtendedLogRecordBuilder) delegateLogger.logRecordBuilder());
+      if (payload != null) {
+        logRecordBuilder.setBody(payload);
+      }
+      logRecordBuilder
+          .setSeverity(DEFAULT_SEVERITY)
+          .setContext(Context.current())
+          .setTimestamp(now, TimeUnit.NANOSECONDS)
+          .setObservedTimestamp(now, TimeUnit.NANOSECONDS);
       addEventName(logRecordBuilder, eventName);
       logRecordBuilder.emit();
     }

sdk/logs/src/test/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProviderTest.java

@@ -17,6 +17,7 @@
 import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
 import io.opentelemetry.sdk.logs.ReadWriteLogRecord;
 import io.opentelemetry.sdk.logs.SdkLoggerProvider;
+import io.opentelemetry.sdk.logs.data.Body;
 import io.opentelemetry.sdk.resources.Resource;
 import java.util.Collections;
 import java.util.concurrent.TimeUnit;
@@ -39,7 +40,23 @@ class SdkEventEmitterProviderTest {
           clock);
 
   @Test
-  void emit() {
+  void emit_NoPayload() {
+    when(clock.now()).thenReturn(10L);
+
+    eventEmitterProvider.eventEmitterBuilder("test-scope").build().emit("namespace.event-name");
+
+    assertThat(seenLog.get().toLogRecordData())
+        .hasResource(RESOURCE)
+        .hasInstrumentationScope(InstrumentationScopeInfo.create("test-scope"))
+        .hasTimestamp(10L)
+        .hasObservedTimestamp(10L)
+        .hasSeverity(Severity.INFO)
+        .hasAttributes(Attributes.builder().put("event.name", "namespace.event-name").build());
+    assertThat(seenLog.get().toLogRecordData().getBody()).isEqualTo(Body.empty());
+  }
+
+  @Test
+  void emit_WithPayload() {
     when(clock.now()).thenReturn(10L);
 
     AnyValue<?> payload = AnyValue.of(Collections.singletonMap("key1", AnyValue.of("value1")));