Mybaits源码分析五之XMLConfigBuilder类 typeAliases 标签解析

 1 private void parseConfiguration(XNode root) {
 2     try {
 3       //解析子节点的properties文件
 4       propertiesElement(root.evalNode("properties"));
 5       //加载用户自定义配置
 6       Properties settings = settingsAsProperties(root.evalNode("settings"));
 7       //加载vfs虚拟文件系统配置
 8       loadCustomVfs(settings);
 9      // 解析子节点typeAliases 别名
10       typeAliasesElement(root.evalNode("typeAliases"));
11       //解析子节点plugins 插件
12       pluginElement(root.evalNode("plugins"));
13       //解析子节点objectFactory mybatis为结果创建对象时都会用到objectFactory
14       objectFactoryElement(root.evalNode("objectFactory"));
15       //解析子节点的封装对象
16       objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
17       reflectorFactoryElement(root.evalNode("reflectorFactory"));
18       //解析settings标签的文件配置
19       settingsElement(settings);
20       //配置运行环境
21       environmentsElement(root.evalNode("environments"));
22       //解析子节点配置数据库供应商
23       databaseIdProviderElement(root.evalNode("databaseIdProvider"));
24       //解析对象类型处理器，处理Java的pojo类型与数据库类型的映射
25       typeHandlerElement(root.evalNode("typeHandlers"));
26       //解析子节点的mappers
27       mapperElement(root.evalNode("mappers"));
28     } catch (Exception e) {
29       throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
30     }
31   }

1 <typeAliases>
2 <!-- 单个别名的定义 alias：别名，type：别名映射的类型 -->
3     <typeAlias type="com.ssc.demo.mybatis.pojo.Subject" alias="testAlias"></typeAlias>
4 <!-- 批量别名定义 指定包路径，自动扫描包下边的pojo，定义别名，别名默认为类名（首字母小写或大写） -->
5     <package name="com.ssc.demo.mybatis.pojo"/>
6 </typeAliases>

 1 private void typeAliasesElement(XNode parent) {
 2     if (parent != null) {
 3       for (XNode child : parent.getChildren()) {
 4       //如果子节点为 package 属性
 5         if ("package".equals(child.getName())) {
 6            //获取包名
 7           String typeAliasPackage = child.getStringAttribute("name");
 8           //将包名下的类自动扫描pojo,定义别名
 9           configuration.getTypeAliasRegistry().registerAliases(typeAliasPackage);
10         } else {
11         //如果子节点为 typeAlias 
12           String alias = child.getStringAttribute("alias");
13           String type = child.getStringAttribute("type");
14           try {
15             //创建类实例
16             Class<?> clazz = Resources.classForName(type);
17             if (alias == null) {
18                //如果别名为空，则默认为类名为别名
19               typeAliasRegistry.registerAlias(clazz);
20             } else {
21               typeAliasRegistry.registerAlias(alias, clazz);
22             }
23           } catch (ClassNotFoundException e) {
24             throw new BuilderException("Error registering typeAlias for '" + alias + "'. Cause: " + e, e);
25           }
26         }
27       }
28     }
29   }

 1 //事务方式别名
 2 typeAliasRegistry.registerAlias("JDBC",JdbcTransactionFactory.class);
 3 typeAliasRegistry.registerAlias("MANAGED",ManagedTransactionFactory.class);
 4 //数据源类型别名
 5 typeAliasRegistry.registerAlias("JNDI",JndiDataSourceFactory.class);
 6 typeAliasRegistry.registerAlias("POOLED",
 7 PooledDataSourceFactory.class);
 8 typeAliasRegistry.registerAlias("UNPOOLED",UnpooledDataSourceFactory.class);
 9 //缓存策略别名
10 typeAliasRegistry.registerAlias("PERPETUAL",PerpetualCache.class);
11 typeAliasRegistry.registerAlias("FIFO",FifoCache.class);
12 typeAliasRegistry.registerAlias("LRU",LruCache.class); typeAliasRegistry.registerAlias("SOFT", SoftCache.class); typeAliasRegistry.registerAlias("WEAK", WeakCache.class);
13 //数据库标识别名
14 typeAliasRegistry.registerAlias("DB_VENDOR",
15 VendorDatabaseIdProvider.class);
16 //语言驱动类别名
17 typeAliasRegistry.registerAlias("XML",XMLLanguageDriver.class);
18 typeAliasRegistry.registerAlias("RAW",RawLanguageDriver.class);
19 //日志类别名
20 typeAliasRegistry.registerAlias("SLF4J", Slf4jImpl.class);
21 typeAliasRegistry.registerAlias("COMMONS_LOGGTNG",JakartmCommonsLogginglmpl.class);
22 typeAliasRegistry.registerAlias("LOG4J", Log4jImpl.class);
23 typeAliasRegistry.registerAlias("LOG4J2", Log4j2Impl.class);
24 typeAliasRegistry.registerAlias("JDK_LOGGING", Jdk14LoggingImpl.class);
25 typeAliasRegistry.registerAlias("STDOUT_LOGGING", StdOutImpl.class);
26 typeAliasRegistry.registerAlias("NO_LOGGING",NoLoggingImpl.class);
27 //动态代理别名
28 typeAliasRegistry.registerAlias("CGLIB",CglibProxyFactory.class);
29 typeAliasRegistry.registerAlias("JAVASSIST",JavassistProxyFactory.class);