#316: Improve error handling for invalid log level

doc/changes/changes_18.0.2.md

@@ -26,6 +26,7 @@ Code name: Improve code quality
 * #307: Fixed `PushdownSqlRenderer` so `HASHTYPE` data types include `bytesize` in rendered pushdown SQL JSON.
 * #313: Fixed mutable DTO and SQL AST collection handling by adding defensive copies, unmodifiable getters, null-to-empty normalization, and constructor-time `SqlOrderBy` validation.
 * #312: Fixed logging utility resource and handler lifecycle issues by closing version metadata streams, falling back when the thread context class loader is missing, defaulting absent version properties to `UNKNOWN`, closing replaced root log handlers, and resetting closed remote socket handlers before reuse.
+* #316: Fixed `LoggingConfiguration` so invalid `LOG_LEVEL` values now fail with a structured error message that names the invalid value and lists the available log levels.
 * #318: Fixed several small naming, Javadoc, message, and parsing robustness issues, including locale-independent SQL parser uppercasing and trimmed telemetry property parsing.
 * Fixed `ColumnMetadata.toString()` so `defaultValue` quotes stay balanced even when no comment is set.
 * #314: Fixed `SqlFunctionAggregateListagg.Behavior` so LISTAGG overflow behavior is null-safe, value-based, and constructed immutably by the parser.

error_code_config.yml

@@ -2,4 +2,4 @@ error-tags:
   VSCOMJAVA:
     packages:
       - com.exasol
-    highest-index: 46
+    highest-index: 47

src/main/java/com/exasol/adapter/request/LoggingConfiguration.java

@@ -4,16 +4,21 @@
 import static com.exasol.adapter.AdapterProperties.LOG_LEVEL_PROPERTY;
 
 import java.io.Serializable;
+import java.util.List;
 import java.util.Map;
 import java.util.logging.Level;
 
+import com.exasol.errorreporting.ExaError;
+
 /**
  * This class represents the logging configuration set in the request properties
  */
 public final class LoggingConfiguration implements Serializable {
     private static final long serialVersionUID = 1930189191497837644L;
     private static final int DEFAULT_REMOTE_LOGGING_PORT = 3000;
     private static final Level DEFAULT_LOG_LEVEL = Level.INFO;
+    private static final List<Level> AVAILABLE_LOG_LEVELS = List.of(Level.OFF, Level.SEVERE, Level.WARNING, Level.INFO, Level.CONFIG, Level.FINE, Level.FINER,
+            Level.FINEST, Level.ALL);
     /** {@code true} if the adapter should send its log messages to a remote log receiver */
     private final boolean logRemotely;
     /** Name host name where the log receiver listens */
@@ -105,13 +110,20 @@ public static LoggingConfiguration parseFromPropertiesWithDebugAddressGiven(fina
     }
 
     private static Level parseLogLevel(final Map<String, String> properties) {
-        final Level level;
-        if (properties.containsKey(LOG_LEVEL_PROPERTY)) {
-            level = Level.parse(properties.get(LOG_LEVEL_PROPERTY));
-        } else {
-            level = DEFAULT_LOG_LEVEL;
+        if (!properties.containsKey(LOG_LEVEL_PROPERTY)) {
+            return DEFAULT_LOG_LEVEL;
+        }
+        final String configuredLogLevel = properties.get(LOG_LEVEL_PROPERTY);
+        try {
+            return Level.parse(configuredLogLevel);
+        } catch (final IllegalArgumentException exception) {
+            throw new IllegalArgumentException(ExaError.messageBuilder("E-VSCOMJAVA-47")
+                    .message("Invalid value {{log_level_value}} for property {{log_level_property}}.")
+                    .mitigation("Available log levels are: {{available_log_levels}}.")
+                    .parameter("log_level_value", configuredLogLevel)
+                    .parameter("log_level_property", LOG_LEVEL_PROPERTY)
+                    .parameter("available_log_levels", AVAILABLE_LOG_LEVELS).toString(), exception);
         }
-        return level;
     }
 
     /**

src/test/java/com/exasol/adapter/request/LoggingConfigurationTest.java

@@ -5,6 +5,7 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -62,6 +63,16 @@ void testGetLogLevel() {
         assertThat(createLoggingConfiguration(this.properties).getLogLevel(), equalTo(Level.FINEST));
     }
 
+    @Test
+    void testInvalidLogLevelThrowsHelpfulException() {
+        this.properties.put(LOG_LEVEL_PROPERTY, "invalid");
+        final IllegalArgumentException exception = assertThrows(IllegalArgumentException.class,
+                () -> createLoggingConfiguration(this.properties));
+        assertThat(exception.getMessage(), equalTo(
+                "E-VSCOMJAVA-47: Invalid value 'invalid' for property 'LOG_LEVEL'. "
+                        + "Available log levels are: [OFF, SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST, ALL]."));
+    }
+
     @Test
     void testFallBackToLocalLoggingInCaseOfIllegalLoggingPort() {
         this.properties.put(DEBUG_ADDRESS_PROPERTY, "www.example.org:illegal_non_numeric_port");