mybatis源码解析4---Configuration解析

 <?xml version="1.0" encoding="UTF-8"?>    

 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">

 <!-- 全局配置顶级节点 -->

 <configuration>    

      <!-- 属性配置,读取properties中的配置文件 -->

     <properties resource="db.propertis">

        <property name="XXX" value="XXX"/>

     </properties>

     <!-- 类型别名 -->

     <typeAliases>

        <!-- 在用到User类型的时候,可以直接使用别名,不需要输入User类的全部路径 -->

        <typeAlias type="com.luck.codehelp.entity.User" alias="user"/>

     </typeAliases>

     <!-- 类型处理器 -->

     <typeHandlers>

         <!-- 类型处理器的作用是完成JDBC类型和java类型的转换,mybatis默认已经由了很多类型处理器,正常无需自定义-->

     </typeHandlers>

     <!-- 对象工厂 -->

     <!-- mybatis创建结果对象的新实例时,会通过对象工厂来完成，mybatis有默认的对象工厂，正常无需配置 -->

     <objectFactory type=""></objectFactory>

     <!-- 插件 -->

     <plugins>

         <!-- 可以自定义拦截器通过plugin标签加入 -->

        <plugin interceptor="com.lucky.interceptor.MyPlugin"></plugin>

     </plugins>

     <!-- 全局配置参数 -->

     <settings>

         <setting name="cacheEnabled" value="false" />

         <setting name="useGeneratedKeys" value="true" /><!-- 是否自动生成主键 -->

         <setting name="defaultExecutorType" value="REUSE" />

         <setting name="lazyLoadingEnabled" value="true"/><!-- 延迟加载标识 -->

         <setting name="aggressiveLazyLoading" value="true"/><!--有延迟加载属性的对象是否延迟加载 -->

         <setting name="multipleResultSetsEnabled" value="true"/><!-- 是否允许单个语句返回多个结果集 -->

         <setting name="useColumnLabel" value="true"/><!-- 使用列标签而不是列名 -->

         <setting name="autoMappingBehavior" value="PARTIAL"/><!-- 指定mybatis如何自动映射列到字段属性;NONE:自动映射;PARTIAL:只会映射结果没有嵌套的结果;FULL:可以映射任何复杂的结果 -->

         <setting name="defaultExecutorType" value="SIMPLE"/><!-- 默认执行器类型 -->

         <setting name="defaultFetchSize" value=""/>

         <setting name="defaultStatementTimeout" value="5"/><!-- 驱动等待数据库相应的超时时间 ,单位是秒-->

         <setting name="safeRowBoundsEnabled" value="false"/><!-- 是否允许使用嵌套语句RowBounds -->

         <setting name="safeResultHandlerEnabled" value="true"/>

         <setting name="mapUnderscoreToCamelCase" value="false"/><!-- 下划线列名是否自动映射到驼峰属性：如user_id映射到userId -->

         <setting name="localCacheScope" value="SESSION"/><!-- 本地缓存（session是会话级别） -->

         <setting name="jdbcTypeForNull" value="OTHER"/><!-- 数据为空值时,没有特定的JDBC类型的参数的JDBC类型 -->

         <setting name="lazyLoadTriggerMethods" value="equals,clone,hashCode,toString"/><!-- 指定触发延迟加载的对象的方法 -->

         <setting name="callSettersOnNulls" value="false"/><!--如果setter方法或map的put方法，如果检索到的值为null时，数据是否有用  -->

         <setting name="logPrefix" value="XXXX"/><!-- mybatis日志文件前缀字符串 -->

         <setting name="logImpl" value="SLF4J"/><!-- mybatis日志的实现类 -->

         <setting name="proxyFactory" value="CGLIB"/><!-- mybatis代理工具 -->

     </settings>  

     <!-- 环境配置集合 -->

     <environments default="development">

         <environment id="development">

             <transactionManager type="JDBC"/><!-- 事务管理器 -->

             <dataSource type="POOLED"><!-- 数据库连接池 -->

                 <property name="driver" value="com.mysql.jdbc.Driver" />

                 <property name="url" value="jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=UTF-8" />

                 <property name="username" value="root" />

                 <property name="password" value="*****" />

             </dataSource>

         </environment>

     </environments>    

     <!-- mapper文件映射配置 -->

     <mappers>

         <mapper resource="com/luck/codehelp/mapper/UserMapper.xml"/>

     </mappers>

 </configuration>   

   protected Environment environment;//运行环境

   protected boolean safeRowBoundsEnabled = false;

   protected boolean safeResultHandlerEnabled = true;

   protected boolean mapUnderscoreToCamelCase = false;

   protected boolean aggressiveLazyLoading = true; //true：有延迟加载属性的对象被调用时完全加载任意属性;false：每个属性按需要加载

   protected boolean multipleResultSetsEnabled = true;//是否允许多种结果集从一个单独的语句中返回

   protected boolean useGeneratedKeys = false;//是否支持自动生成主键

   protected boolean useColumnLabel = true;//是否使用列标签

   protected boolean cacheEnabled = true;//是否使用缓存标识

   protected boolean callSettersOnNulls = false;//

   protected boolean useActualParamName = true;

   protected String logPrefix;

   protected Class <? extends Log> logImpl;

   protected Class <? extends VFS> vfsImpl;

   protected LocalCacheScope localCacheScope = LocalCacheScope.SESSION;

   protected JdbcType jdbcTypeForNull = JdbcType.OTHER;

   protected Set<String> lazyLoadTriggerMethods = new HashSet<String>(Arrays.asList(new String[] { "equals", "clone", "hashCode", "toString" }));

   protected Integer defaultStatementTimeout;

   protected Integer defaultFetchSize;

   protected ExecutorType defaultExecutorType = ExecutorType.SIMPLE;

   protected AutoMappingBehavior autoMappingBehavior = AutoMappingBehavior.PARTIAL;//指定mybatis如果自动映射列到字段和属性,PARTIAL会自动映射简单的没有嵌套的结果,FULL会自动映射任意复杂的结果

   protected AutoMappingUnknownColumnBehavior autoMappingUnknownColumnBehavior = AutoMappingUnknownColumnBehavior.NONE;

   protected Properties variables = new Properties();

   protected ReflectorFactory reflectorFactory = new DefaultReflectorFactory();

   protected ObjectFactory objectFactory = new DefaultObjectFactory();

   protected ObjectWrapperFactory objectWrapperFactory = new DefaultObjectWrapperFactory();

   protected boolean lazyLoadingEnabled = false;//是否延时加载，false则表示所有关联对象即使加载,true表示延时加载

   protected ProxyFactory proxyFactory = new JavassistProxyFactory(); // #224 Using internal Javassist instead of OGNL

   protected String databaseId;

   protected Class<?> configurationFactory;

   protected final MapperRegistry mapperRegistry = new MapperRegistry(this);

   protected final InterceptorChain interceptorChain = new InterceptorChain();

   protected final TypeHandlerRegistry typeHandlerRegistry = new TypeHandlerRegistry();

   protected final TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();

   protected final LanguageDriverRegistry languageRegistry = new LanguageDriverRegistry();

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

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

   protected final Map<String, ResultMap> resultMaps = new StrictMap<ResultMap>("Result Maps collection");

   protected final Map<String, ParameterMap> parameterMaps = new StrictMap<ParameterMap>("Parameter Maps collection");

   protected final Map<String, KeyGenerator> keyGenerators = new StrictMap<KeyGenerator>("Key Generators collection");

   protected final Set<String> loadedResources = new HashSet<String>(); //已经加载过的resource(mapper)

   protected final Map<String, XNode> sqlFragments = new StrictMap<XNode>("XML fragments parsed from previous mappers");

   protected final Collection<XMLStatementBuilder> incompleteStatements = new LinkedList<XMLStatementBuilder>();

   protected final Collection<CacheRefResolver> incompleteCacheRefs = new LinkedList<CacheRefResolver>();

   protected final Collection<ResultMapResolver> incompleteResultMaps = new LinkedList<ResultMapResolver>();

   protected final Collection<MethodResolver> incompleteMethods = new LinkedList<MethodResolver>();

   protected final Map<String, String> cacheRefMap = new HashMap<String, String>();