feat: allow DefaultSqlSessionFactory to provide a custom SqlSession

Additionally, allow subclasses of DefaultSqlSession to call `selectList(...)`

Author: willie

src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSession.java

@@ -147,7 +147,8 @@ public <E> List<E> selectList(String statement, Object parameter, RowBounds rowB
     return selectList(statement, parameter, rowBounds, Executor.NO_RESULT_HANDLER);
   }
 
-  private <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds, ResultHandler handler) {
+  protected final <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds,
+      ResultHandler handler) {
     try {
       MappedStatement ms = configuration.getMappedStatement(statement);
       dirty |= ms.isDirtySelect();

src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSessionFactory.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2023 the original author or authors.
+ *    Copyright 2009-2024 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -87,6 +87,10 @@ public Configuration getConfiguration() {
     return configuration;
   }
 
+  protected SqlSession createSqlSession(Configuration configuration, Executor executor, boolean autoCommit) {
+    return new DefaultSqlSession(configuration, executor, autoCommit);
+  }
+
   private SqlSession openSessionFromDataSource(ExecutorType execType, TransactionIsolationLevel level,
       boolean autoCommit) {
     Transaction tx = null;
@@ -95,7 +99,7 @@ private SqlSession openSessionFromDataSource(ExecutorType execType, TransactionI
       final TransactionFactory transactionFactory = getTransactionFactoryFromEnvironment(environment);
       tx = transactionFactory.newTransaction(environment.getDataSource(), level, autoCommit);
       final Executor executor = configuration.newExecutor(tx, execType);
-      return new DefaultSqlSession(configuration, executor, autoCommit);
+      return createSqlSession(configuration, executor, autoCommit);
     } catch (Exception e) {
       closeTransaction(tx); // may have fetched a connection so lets call close()
       throw ExceptionFactory.wrapException("Error opening session.  Cause: " + e, e);
@@ -118,7 +122,7 @@ private SqlSession openSessionFromConnection(ExecutorType execType, Connection c
       final TransactionFactory transactionFactory = getTransactionFactoryFromEnvironment(environment);
       final Transaction tx = transactionFactory.newTransaction(connection);
       final Executor executor = configuration.newExecutor(tx, execType);
-      return new DefaultSqlSession(configuration, executor, autoCommit);
+      return createSqlSession(configuration, executor, autoCommit);
     } catch (Exception e) {
       throw ExceptionFactory.wrapException("Error opening session.  Cause: " + e, e);
     } finally {

src/test/java/org/apache/ibatis/session/defaults/ExtendedSqlSession.java

@@ -0,0 +1,29 @@
+package org.apache.ibatis.session.defaults;
+
+import java.util.List;
+
+import org.apache.ibatis.executor.Executor;
+import org.apache.ibatis.session.Configuration;
+import org.apache.ibatis.session.ResultContext;
+import org.apache.ibatis.session.ResultHandler;
+import org.apache.ibatis.session.RowBounds;
+
+public class ExtendedSqlSession extends DefaultSqlSession {
+
+  public ExtendedSqlSession(Configuration configuration, Executor executor, boolean autoCommit) {
+    super(configuration, executor, autoCommit);
+  }
+
+  @Override
+  public <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds) {
+    return super.selectList(statement, parameter, rowBounds, new GlobalIfNotSetResultHandler());
+  }
+
+  private static final class GlobalIfNotSetResultHandler implements ResultHandler {
+
+    @Override
+    public void handleResult(ResultContext resultContext) {
+      // demonstrates how to globally set a result handler if one was not specified
+    }
+  }
+}

src/test/java/org/apache/ibatis/session/defaults/ExtendedSqlSessionFactory.java

@@ -0,0 +1,17 @@
+package org.apache.ibatis.session.defaults;
+
+import org.apache.ibatis.executor.Executor;
+import org.apache.ibatis.session.Configuration;
+import org.apache.ibatis.session.SqlSession;
+
+public class ExtendedSqlSessionFactory extends DefaultSqlSessionFactory {
+
+  public ExtendedSqlSessionFactory(Configuration configuration) {
+    super(configuration);
+  }
+
+  @Override
+  protected SqlSession createSqlSession(Configuration configuration, Executor executor, boolean autoCommit) {
+    return new ExtendedSqlSession(configuration, executor, autoCommit);
+  }
+}

src/test/java/org/apache/ibatis/session/defaults/ExtendedSqlSessionFactoryBuilder.java

@@ -0,0 +1,13 @@
+package org.apache.ibatis.session.defaults;
+
+import org.apache.ibatis.session.Configuration;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+
+public class ExtendedSqlSessionFactoryBuilder extends SqlSessionFactoryBuilder {
+
+  @Override
+  public SqlSessionFactory build(Configuration config) {
+    return new ExtendedSqlSessionFactory(config);
+  }
+}

src/test/java/org/apache/ibatis/session/defaults/ExtendedSqlSessionFactoryTest.java

@@ -0,0 +1,23 @@
+package org.apache.ibatis.session.defaults;
+
+import java.io.Reader;
+
+import org.apache.ibatis.BaseDataTest;
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+
+public class ExtendedSqlSessionFactoryTest extends BaseDataTest {
+
+  @Test
+  public void testCanUseExtendedSqlSessionUsingDefaults() throws Exception {
+    createBlogDataSource();
+
+    final String resource = "org/apache/ibatis/builder/MapperConfig.xml";
+    final Reader reader = Resources.getResourceAsReader(resource);
+
+    SqlSessionFactory sqlMapper = new ExtendedSqlSessionFactoryBuilder().build(reader);
+    Assertions.assertThat(sqlMapper).isNotNull();
+  }
+}