add option to customize log level for exceptions

endpoints-framework/src/main/java/com/google/api/server/spi/ServiceException.java

@@ -16,6 +16,7 @@
 package com.google.api.server.spi;
 
 import java.util.Map;
+import java.util.logging.Level;
 
 /**
  * Generic service exception that, in addition to a status message, has a status code, and
@@ -26,6 +27,7 @@ public class ServiceException extends Exception {
   protected final int statusCode;
   protected final String reason;
   protected final String domain;
+  protected Level logLevel;
 
   public ServiceException(int statusCode, String statusMessage) {
     super(statusMessage);
@@ -99,4 +101,17 @@ public String getDomain() {
   public Map<String, String> getHeaders() {
     return null;
   }
+
+  public Level getLogLevel() {
+    return logLevel == null ? getDefaultLoggingLevel(statusCode) : logLevel;
+  }
+
+  private static Level getDefaultLoggingLevel(int statusCode) {
+    return statusCode >= 500 ? Level.SEVERE : Level.INFO;
+  }
+
+  public static <T extends ServiceException> T withLogLevel(T exception, Level level) {
+    exception.logLevel = level;
+    return exception;
+  }
 }

endpoints-framework/src/main/java/com/google/api/server/spi/SystemService.java

@@ -366,16 +366,15 @@ public void invokeServiceMethod(Object service, Method method, ParamReader param
         resultWriter.writeError(new UnauthorizedException(cause));
       } else if (cause.getCause() != null && cause.getCause() instanceof ServiceException) {
         ServiceException serviceException = (ServiceException) cause.getCause();
-        level = getLoggingLevel(serviceException);
+        level = serviceException.getLogLevel();
         resultWriter.writeError(serviceException);
       } else {
         level = Level.SEVERE;
         resultWriter.writeError(new InternalServerErrorException(cause));
       }
       logger.log(level, "exception occurred while calling backend method", cause);
     } catch (ServiceException e) {
-      Level level = getLoggingLevel(e);
-      logger.log(level, "exception occurred while calling backend method", e);
+      logger.log(e.getLogLevel(), "exception occurred while calling backend method", e);
       resultWriter.writeError(e);
     }
   }
@@ -401,10 +400,6 @@ private void validateRegisteredServices(ApiConfigValidator validator) throws Api
     }
   }
 
-  private static Level getLoggingLevel(ServiceException e) {
-    return e.getStatusCode() >= 500 ? Level.SEVERE : Level.INFO;
-  }
-
   private static boolean isOAuthRequestException(Class<?> clazz) {
     while (Object.class != clazz) {
       if (OAUTH_EXCEPTION_CLASS.equals(clazz.getName())) {

endpoints-framework/src/test/java/com/google/api/server/spi/ServiceExceptionTest.java

@@ -0,0 +1,20 @@
+package com.google.api.server.spi;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.api.server.spi.response.UnauthorizedException;
+import java.util.logging.Level;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class ServiceExceptionTest {
+  @Test
+  public void testWithLogLevel() {
+    UnauthorizedException ex = new UnauthorizedException("");
+    assertThat(ex.getLogLevel()).isEqualTo(Level.INFO);
+    assertThat(ServiceException.withLogLevel(ex, Level.WARNING).getLogLevel())
+        .isEqualTo(Level.WARNING);
+  }
+}