详解Mybatis是如何解析配置文件的

public class Configuration {
 //环境
 protected Environment environment;
 protected boolean safeRowBoundsEnabled;
 protected boolean safeResultHandlerEnabled = true;
 protected boolean mapUnderscoreToCamelCase;
 protected boolean aggressiveLazyLoading;
 protected boolean multipleResultSetsEnabled = true;
 protected boolean useGeneratedKeys;
 protected boolean useColumnLabel = true;
 protected boolean cacheEnabled = true;
 protected boolean callSettersOnNulls;
 protected boolean useActualParamName = true;
 protected boolean returnInstanceForEmptyRow;
 
 //日志信息的前缀
 protected String logPrefix;
 
 //日志接口
 protected Class<? extends Log> logImpl;
 
 //文件系统接口
 protected Class<? extends VFS> vfsImpl;
 
 //本地Session范围
 protected LocalCacheScope localCacheScope = LocalCacheScope.SESSION;
 
 //数据库类型
 protected JdbcType jdbcTypeForNull = JdbcType.OTHER;
 
 //延迟加载的方法
 protected Set<String> lazyLoadTriggerMethods = new HashSet<String>(
   Arrays.asList(new String[] { "equals", "clone", "hashCode", "toString" }));
 
 //默认执行语句超时
 protected Integer defaultStatementTimeout;
 
 //默认的执行器
 protected ExecutorType defaultExecutorType = ExecutorType.SIMPLE;
 
 //数据库ID
 protected String databaseId;
 
 //mapper注册表
 protected final MapperRegistry mapperRegistry = new MapperRegistry(this);
 
 //拦截器链
 protected final InterceptorChain interceptorChain = new InterceptorChain();
 
 //类型处理器
 protected final TypeHandlerRegistry typeHandlerRegistry = new TypeHandlerRegistry();
 
 //类型别名
 protected final TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
 
 //语言驱动
 protected final LanguageDriverRegistry languageRegistry = new LanguageDriverRegistry();

 //mapper_id 和 mapper文件的映射
 protected final Map<String, MappedStatement> mappedStatements = new StrictMap<MappedStatement>(
   "Mapped Statements collection");
   
 //mapper_id和缓存的映射
 protected final Map<String, Cache> caches = new StrictMap<Cache>("Caches collection");
 
 //mapper_id和返回值的映射
 protected final Map<String, ResultMap> resultMaps = new StrictMap<ResultMap>("Result Maps collection");
 
 //mapper_id和参数的映射
 protected final Map<String, ParameterMap> parameterMaps = new StrictMap<ParameterMap>("Parameter Maps collection");
 
 //资源列表
 protected final Set<String> loadedResources = new HashSet<String>();
 
 未完.......
}

private void parseConfiguration(XNode root) {
 try {
 //issue #117 read properties first
 propertiesElement(root.evalNode("properties"));
 Properties settings = settingsAsProperties(root.evalNode("settings"));
 loadCustomVfs(settings);
 loadCustomLogImpl(settings);
 typeAliasesElement(root.evalNode("typeAliases"));
 pluginElement(root.evalNode("plugins"));
 objectFactoryElement(root.evalNode("objectFactory"));
 objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
 reflectorFactoryElement(root.evalNode("reflectorFactory"));
 settingsElement(settings);
 // read it after objectFactory and objectWrapperFactory issue #631
 environmentsElement(root.evalNode("environments"));
 databaseIdProviderElement(root.evalNode("databaseIdProvider"));
 typeHandlerElement(root.evalNode("typeHandlers"));
 mapperElement(root.evalNode("mappers"));
 } catch (Exception e) {
 throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
 }
}

configuration.addMappedStatement(statement);

protected final Map<String, MappedStatement> mappedStatements = new StrictMap<MappedStatement>(
   "Mapped Statements collection");

public void addMappedStatement(MappedStatement ms) {
mappedStatements.put(ms.getId(), ms);
}

public final class MappedStatement {
	private SqlSource sqlSource;
}

public interface SqlSource {
 BoundSql getBoundSql(Object parameterObject);
}

public class BoundSql {
 private final String sql;
 private final List<ParameterMapping> parameterMappings;
}

protected final Map<String, Cache> caches = new StrictMap<>("Caches collection");

public void addCache(Cache cache) {
 caches.put(cache.getId(), cache);
}

public SqlSessionFactory build(Configuration config) {
 return new DefaultSqlSessionFactory(config);
}

public interface SqlSessionFactory {
 SqlSession openSession();
 //其余openSession重载方法略…
 Configuration getConfiguration();
}

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);
 //其余增删查改方法略…
}