fix: EXPOSED-714 Fix NullPointerException when non-object Table is de…

…fined

exposed-spring-boot-starter/src/main/kotlin/org/jetbrains/exposed/spring/DatabaseInitializer.kt

@@ -53,5 +53,5 @@ fun discoverExposedTables(applicationContext: ApplicationContext, excludedPackag
     excludedPackages.forEach { provider.addExcludeFilter(RegexPatternTypeFilter(Pattern.compile(it.replace(".", "\\.") + ".*"))) }
     val packages = AutoConfigurationPackages.get(applicationContext)
     val components = packages.map { provider.findCandidateComponents(it) }.flatten()
-    return components.map { Class.forName(it.beanClassName).kotlin.objectInstance as Table }
+    return components.mapNotNull { Class.forName(it.beanClassName).kotlin.objectInstance as? Table }
 }

exposed-spring-boot-starter/src/test/kotlin/org/jetbrains/exposed/spring/DatabaseInitializerTest.kt

@@ -7,6 +7,7 @@ import org.jetbrains.exposed.sql.Database
 import org.jetbrains.exposed.sql.selectAll
 import org.jetbrains.exposed.sql.transactions.transaction
 import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Assertions.assertArrayEquals
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
@@ -33,4 +34,12 @@ open class DatabaseInitializerTest {
             }
         }
     }
+
+    @Test
+    fun `ignore non object Table`() {
+        Database.connect("jdbc:h2:mem:test-spring", user = "sa", driver = "org.h2.Driver")
+        val tables = discoverExposedTables(applicationContext, listOf())
+        assertEquals(2, tables.size)
+        assertArrayEquals(listOf(TestTable, IgnoreTable).toTypedArray(), tables.toTypedArray())
+    }
 }

exposed-spring-boot-starter/src/test/kotlin/org/jetbrains/exposed/spring/tables/NonObjectTable.kt

@@ -0,0 +1,5 @@
+package org.jetbrains.exposed.spring.tables
+
+import org.jetbrains.exposed.sql.Table
+
+open class NonObjectTable : Table()