MyBatis-03-environment

配置

<environments default="default"><environment id="default"><!-- 事务类型 --><transactionManager type="JDBC"/><!-- 数据源类型 --><dataSource type="POOLED"><!-- 数据库连接基本信息 --><property name="driver" value="com.mysql.cj.jdbc.Driver"/><property name="url"value="jdbc:mysql://127.0.0.1:3306/mybatis_demo01?useUnicode=true&amp;characterEncoding=utf8&amp;connectTimeout=1000&amp;socketTimeout=3000&amp;autoReconnect=true&amp;useSSL=false&amp;serverTimezone=UTC"/><property name="username" value="root"/><property name="password" value="123456"/></dataSource></environment>
</environments>

XMLConfigBuilder#environmentsElement

1. 只解析和 environments-default 相同的 environment 配置节点
2. 可以在 XMLConfigBuilder 构造函数传入 environment 覆盖默认的 default

private void environmentsElement(XNode context) throws Exception {if (context == null) {return;}// 构建函数时可写入，默认为 nullif (environment == null) {environment = context.getStringAttribute("default");}for (XNode child : context.getChildren()) {String id = child.getStringAttribute("id");// 只解析和 environment 名称相同的部分，不是全部解析 & 动态切换if (isSpecifiedEnvironment(id)) {TransactionFactory txFactory = transactionManagerElement(child.evalNode("transactionManager"));DataSourceFactory dsFactory = dataSourceElement(child.evalNode("dataSource"));DataSource dataSource = dsFactory.getDataSource();Environment.Builder environmentBuilder = new Environment.Builder(id).transactionFactory(txFactory).dataSource(dataSource);configuration.setEnvironment(environmentBuilder.build());break;}}
}