package org.apache.ibatis.session; 
import java.sql.Connection; 
public interface SqlSessionFactory { 
  SqlSession openSession();//這個方法最經常用,用來創(chuàng)建SqlSession對象。
  SqlSession openSession(boolean autoCommit); 
  SqlSession openSession(Connection connection); 
  SqlSession openSession(TransactionIsolationLevel level); 
  SqlSession openSession(ExecutorType execType); 
  SqlSession openSession(ExecutorType execType, boolean autoCommit); 
  SqlSession openSession(ExecutorType execType, TransactionIsolationLevel level); 
  SqlSession openSession(ExecutorType execType, Connection connection); 
  Configuration getConfiguration(); 
}

 @Bean
  @ConditionalOnMissingBean
  public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
    //創(chuàng)建SqlSessionFactoryBean對象
     SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
      //設置數據源
    factory.setDataSource(dataSource);
    factory.setVfs(SpringBootVFS.class);
    if (StringUtils.hasText(this.properties.getConfigLocation())) {
     //mybatis ，Xml配置文件路徑
        、factory.setConfigLocation(this.resourceLoader.getResource(this.properties.getConfigLocation()));
    }
      //應用配置文件
    applyConfiguration(factory);
      //Mybatis額外的配置文件
    if (this.properties.getConfigurationProperties() != null) {
      factory.setConfigurationProperties(this.properties.getConfigurationProperties());
    }
      //設置mybatis攔截器
    if (!ObjectUtils.isEmpty(this.interceptors)) {
      factory.setPlugins(this.interceptors);
    }
    ···
      //設置*mapper.xml掃描路徑
    if (!ObjectUtils.isEmpty(this.properties.resolveMapperLocations())) {
      factory.setMapperLocations(this.properties.resolveMapperLocations());
    }
    ····	
        //獲取創(chuàng)建SqlSessionFactoryBean對象
    return factory.getObject();
  }

@Bean
  @ConditionalOnMissingBean
  public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
    ExecutorType executorType = this.properties.getExecutorType();
    if (executorType != null) {
      return new SqlSessionTemplate(sqlSessionFactory, executorType);
    } else {
      return new SqlSessionTemplate(sqlSessionFactory);
    }
  }

  public SqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType,
      PersistenceExceptionTranslator exceptionTranslator) {
    notNull(sqlSessionFactory, "Property 'sqlSessionFactory' is required");
    notNull(executorType, "Property 'executorType' is required");
    this.sqlSessionFactory = sqlSessionFactory;
    this.executorType = executorType;
    this.exceptionTranslator = exceptionTranslator;
    this.sqlSessionProxy = (SqlSession) newProxyInstance(SqlSessionFactory.class.getClassLoader(),
        new Class[] { SqlSession.class }, new SqlSessionInterceptor());
  }

 @Override
  public int insert(String statement, Object parameter) {
    return this.sqlSessionProxy.insert(statement, parameter);
  }
·········

 @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
      SqlSession sqlSession = getSqlSession(SqlSessionTemplate.this.sqlSessionFactory,
          SqlSessionTemplate.this.executorType, SqlSessionTemplate.this.exceptionTranslator);
      try {
        Object result = method.invoke(sqlSession, args);
        if (!isSqlSessionTransactional(sqlSession, SqlSessionTemplate.this.sqlSessionFactory)) {
          // force commit even on non-dirty sessions because some databases require
          // a commit/rollback before calling close()
          sqlSession.commit(true);
        }
        return result;
      } 
  }

 SqlSessionHolder holder = (SqlSessionHolder) TransactionSynchronizationManager.getResource(sessionFactory);
    SqlSession session = sessionHolder(executorType, holder);
    if (session != null) {
      return session;
    }
    LOGGER.debug(() -> "Creating a new SqlSession");
    session = sessionFactory.openSession(executorType);
    registerSessionHolder(sessionFactory, executorType, exceptionTranslator, session);

package org.apache.ibatis.session; 
import java.io.Closeable; 
import java.sql.Connection; 
import java.util.List; 
import java.util.Map; 
import org.apache.ibatis.executor.BatchResult; 
public interface SqlSession extends Closeable { 
  <T> T selectOne(String statement); 
  <T> T selectOne(String statement, Object parameter); 
  <E> List<E> selectList(String statement); 
  <E> List<E> selectList(String statement, Object parameter); 
  <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds); 
  <K, V> Map<K, V> selectMap(String statement, String mapKey); 
  <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey); 
  <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds); 
  void select(String statement, Object parameter, ResultHandler handler); 
  void select(String statement, ResultHandler handler); 
  void select(String statement, Object parameter, RowBounds rowBounds, ResultHandler handler); 
  int insert(String statement); 
  int insert(String statement, Object parameter); 
  int update(String statement); 
  int update(String statement, Object parameter); 
  int delete(String statement); 
  int delete(String statement, Object parameter); 
  void commit(); void commit(boolean force); 
  void rollback(); 
  void rollback(boolean force); 
  List<BatchResult> flushStatements(); 
  void close(); 
  void clearCache(); 
  Configuration getConfiguration(); 
  <T> T getMapper(Class<T> type); 
  Connection getConnection(); 
}

 private SqlSession openSessionFromDataSource(ExecutorType execType, TransactionIsolationLevel level, boolean autoCommit) {
    Transaction tx = null;
    try {
      final Environment environment = configuration.getEnvironment();
      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);
    } catch (Exception e) {
      closeTransaction(tx); // may have fetched a connection so lets call close()
      throw ExceptionFactory.wrapException("Error opening session.  Cause: " + e, e);
    } finally {
      ErrorContext.instance().reset();
    }
  }

  public DefaultSqlSession(Configuration configuration, Executor executor, boolean autoCommit) {
    this.configuration = configuration;
    this.executor = executor;
    this.dirty = false;
    this.autoCommit = autoCommit;
  }

@Override
  public void commit(boolean force) {
    try {
      executor.commit(isCommitOrRollbackRequired(force));
      dirty = false;
    } catch (Exception e) {
      throw ExceptionFactory.wrapException("Error committing transaction.  Cause: " + e, e);
    } finally {
      ErrorContext.instance().reset();
    }
  }