Changes to support looking up a Dialect by name.

transactionoutbox-core/src/main/java/com/gruelbox/transactionoutbox/Dialect.java

@@ -3,10 +3,13 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.List;
 import java.util.stream.Stream;
 
 /** The SQL dialects supported by {@link DefaultPersistor}. */
 public interface Dialect {
+  String getName();
+
   String getDelete();
 
   /**
@@ -201,4 +204,16 @@ public interface Dialect {
                 }
               })
           .build();
+
+  List<Dialect> dialects = List.of(MY_SQL_5, MY_SQL_8, POSTGRESQL_9, H2, ORACLE, MS_SQL_SERVER);
+
+  static Dialect getValueByName(String dialectName) {
+    for (Dialect item : dialects) {
+      if (item.getName().equals(dialectName)) {
+        return item;
+      }
+    }
+    throw new RuntimeException(
+        "Unknown dialect: " + dialectName + ". Valid dialects are: " + dialects + ".");
+  }
 }

transactionoutbox-core/src/test/java/com/gruelbox/transactionoutbox/DialectTest.java

@@ -0,0 +1,46 @@
+package com.gruelbox.transactionoutbox;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class DialectTest {
+  @Test
+  void testWhenDialectNameDoesNotExist_shouldThrowException() {
+    // Given
+    String dialectName = "bad dialect";
+
+    // When
+    Exception result =
+        assertThrows(RuntimeException.class, () -> Dialect.getValueByName(dialectName));
+
+    // Then
+    assertTrue(result.getMessage().startsWith("Unknown dialect: " + dialectName));
+    System.out.println(result.getMessage());
+  }
+
+  @Test
+  void testWhenDialectNameDoesExistsButInvalidCase_shouldThrowException() {
+    // Given
+    String dialectName = "h2";
+
+    // When
+    Exception result =
+        assertThrows(RuntimeException.class, () -> Dialect.getValueByName(dialectName));
+
+    // Then
+    assertTrue(result.getMessage().startsWith("Unknown dialect: " + dialectName));
+  }
+
+  @Test
+  void testWhenDialectNameDoesExist_shouldReturnDialect() {
+    // Given
+    String dialectName = "H2";
+
+    // When
+    Dialect result = Dialect.getValueByName(dialectName);
+
+    // Then
+    assertEquals(Dialect.H2, result);
+  }
+}

transactionoutbox-spring/src/test/java/com/gruelbox/transactionoutbox/spring/example/StringToDialectConverter.java

@@ -0,0 +1,14 @@
+package com.gruelbox.transactionoutbox.spring.example;
+
+import com.gruelbox.transactionoutbox.Dialect;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.stereotype.Component;
+
+@Component
+public class StringToDialectConverter implements Converter<String, Dialect> {
+
+  @Override
+  public Dialect convert(String source) {
+    return Dialect.getValueByName(source);
+  }
+}

transactionoutbox-spring/src/test/java/com/gruelbox/transactionoutbox/spring/example/TransactionOutboxProperties.java

@@ -1,5 +1,6 @@
 package com.gruelbox.transactionoutbox.spring.example;
 
+import com.gruelbox.transactionoutbox.Dialect;
 import java.time.Duration;
 import lombok.Data;
 import org.springframework.boot.context.properties.ConfigurationProperties;
@@ -13,4 +14,5 @@ class TransactionOutboxProperties {
   private boolean useJackson;
   private Duration attemptFrequency;
   private int blockAfterAttempts;
+  private Dialect dialect;
 }

transactionoutbox-spring/src/test/java/com/gruelbox/transactionoutbox/spring/example/TransactionOutboxSpringDemoApplication.java

@@ -2,16 +2,20 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.gruelbox.transactionoutbox.DefaultPersistor;
-import com.gruelbox.transactionoutbox.Dialect;
 import com.gruelbox.transactionoutbox.Persistor;
 import com.gruelbox.transactionoutbox.TransactionOutbox;
 import com.gruelbox.transactionoutbox.jackson.JacksonInvocationSerializer;
 import com.gruelbox.transactionoutbox.spring.SpringInstantiator;
 import com.gruelbox.transactionoutbox.spring.SpringTransactionManager;
+import java.util.HashSet;
+import java.util.Set;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Lazy;
+import org.springframework.context.support.ConversionServiceFactoryBean;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.scheduling.annotation.EnableScheduling;
 
 @SpringBootApplication
@@ -22,16 +26,26 @@ public static void main(String[] args) {
     SpringApplication.run(TransactionOutboxSpringDemoApplication.class, args);
   }
 
+  @Bean
+  ConversionService conversionService() {
+    ConversionServiceFactoryBean factory = new ConversionServiceFactoryBean();
+    Set<Converter<?, ?>> convSet = new HashSet<>();
+    convSet.add(new StringToDialectConverter());
+    factory.setConverters(convSet);
+    factory.afterPropertiesSet();
+    return factory.getObject();
+  }
+
   @Bean
   @Lazy
   Persistor persistor(TransactionOutboxProperties properties, ObjectMapper objectMapper) {
     if (properties.isUseJackson()) {
       return DefaultPersistor.builder()
           .serializer(JacksonInvocationSerializer.builder().mapper(objectMapper).build())
-          .dialect(Dialect.H2)
+          .dialect(properties.getDialect())
           .build();
     } else {
-      return Persistor.forDialect(Dialect.H2);
+      return Persistor.forDialect(properties.getDialect());
     }
   }
 

transactionoutbox-spring/src/test/resources/application.properties

@@ -2,4 +2,5 @@ server.port=8081
 outbox.repeatEvery=PT1S
 outbox.attemptFrequency=PT0.5S
 outbox.blockAfterAttempts=100
-outbox.useJackson=true
+outbox.useJackson=true
+outbox.dialect=H2