Fix byte[] instantiation on MariaDB

Closes #54

CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+
+### Changes
+
+- Fix byte[] instantiation on MariaDB Connector/J 3.x ([#54](https://github.com/EvidentSolutions/dalesbred/pull/54))
+
 ## 1.3.5 (2022-03-02)
 
 ### Changes

dalesbred/src/main/java/org/dalesbred/internal/jdbc/ResultSetUtils.java

@@ -50,6 +50,11 @@ private ResultSetUtils() { }
 
     public static @NotNull Type getColumnType(@NotNull ResultSetMetaData metaData, int column) throws SQLException {
         String className = metaData.getColumnClassName(column);
+
+        // MariaDB Connector/J 3.x encodes byte array types in a way that is incompatible with Class.forName
+        if (className.equals("byte[]"))
+            return byte[].class;
+
         try {
             return Class.forName(className);
         } catch (ClassNotFoundException e) {

dalesbred/src/test/kotlin/org/dalesbred/internal/jdbc/ResultSetUtilsTest.kt

@@ -0,0 +1,30 @@
+package org.dalesbred.internal.jdbc
+
+import org.dalesbred.testutils.unimplemented
+import org.junit.Test
+import java.sql.ResultSetMetaData
+import kotlin.test.assertEquals
+
+class ResultSetUtilsTest {
+
+    @Test
+    fun `column type resolution`() {
+        val metadata = MockResultSetMetaData(
+            classNames = listOf("java.lang.String", "[Ljava.lang.String;", "[B")
+        )
+        assertEquals(String::class.java, ResultSetUtils.getColumnType(metadata, 1))
+        assertEquals(Array<String>::class.java, ResultSetUtils.getColumnType(metadata, 2))
+        assertEquals(ByteArray::class.java, ResultSetUtils.getColumnType(metadata, 3))
+    }
+
+    @Test
+    fun `resolving byte array types for MariaDB`() {
+        val metadata = MockResultSetMetaData(classNames = listOf("byte[]"))
+        assertEquals(ByteArray::class.java, ResultSetUtils.getColumnType(metadata, 1))
+    }
+
+    class MockResultSetMetaData(val classNames: List<String>) : ResultSetMetaData by unimplemented() {
+        override fun getColumnCount() = classNames.size
+        override fun getColumnClassName(column: Int) = classNames[column - 1]
+    }
+}