feat: Use EXCEPTION_MESSAGE_ATTRIBUTE and clean up LoggingTracer

Author: blakeli0

sdk-platform-java/gax-java/gax/src/main/java/com/google/api/gax/tracing/LoggingTracer.java

@@ -35,6 +35,7 @@
 import com.google.api.gax.logging.LoggerProvider;
 import com.google.api.gax.logging.LoggingUtils;
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
 import com.google.rpc.ErrorInfo;
 import java.util.HashMap;
 import java.util.Map;
@@ -80,13 +81,13 @@ void recordActionableError(Throwable error) {
     logContext.putAll(
         ObservabilityUtils.getResponseAttributes(error, apiTracerContext.transport()));
 
-    if (error != null && error.getMessage() != null) {
-      logContext.put("exception.message", error.getMessage());
+    if (!Strings.isNullOrEmpty(error.getMessage())) {
+      logContext.put(ObservabilityAttributes.EXCEPTION_MESSAGE_ATTRIBUTE, error.getMessage());
     }
 
     ErrorInfo errorInfo = ObservabilityUtils.extractErrorInfo(error);
     if (errorInfo != null) {
-      if (errorInfo.getDomain() != null && !errorInfo.getDomain().isEmpty()) {
+      if (!Strings.isNullOrEmpty(errorInfo.getDomain())) {
         logContext.put(ObservabilityAttributes.ERROR_DOMAIN_ATTRIBUTE, errorInfo.getDomain());
       }
       if (errorInfo.getMetadataMap() != null) {

sdk-platform-java/gax-java/gax/src/main/java/com/google/api/gax/tracing/ObservabilityAttributes.java

@@ -85,6 +85,9 @@ public class ObservabilityAttributes {
   /** If the error was caused by an exception, the exception class name. */
   public static final String EXCEPTION_TYPE_ATTRIBUTE = "exception.type";
 
+  /** If the error was caused by an exception, the exception message. */
+  public static final String EXCEPTION_MESSAGE_ATTRIBUTE = "exception.message";
+
   /** Size of the response body in bytes. */
   public static final String HTTP_RESPONSE_BODY_SIZE = "http.response.body.size";
 

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/tracing/LoggingTracerTest.java

@@ -196,7 +196,9 @@ void testRecordActionableError_logsExceptionDetails() {
     assertEquals(
         "java.lang.RuntimeException",
         attributesMap.get(ObservabilityAttributes.EXCEPTION_TYPE_ATTRIBUTE));
-    assertEquals("test error message", attributesMap.get("exception.message"));
+    assertEquals(
+        "test error message",
+        attributesMap.get(ObservabilityAttributes.EXCEPTION_MESSAGE_ATTRIBUTE));
   }
 
   @Test