💡 添加相关注释

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/SpringBootDemoDynamicDatasourceApplication.java

@@ -31,9 +31,12 @@ public class SpringBootDemoDynamicDatasourceApplication implements CommandLineRu
 
     @Override
     public void run(String... args) {
+        // 设置默认的数据源
         DatasourceConfigContextHolder.setDefaultDatasource();
+        // 查询所有数据库配置列表
         List<DatasourceConfig> datasourceConfigs = configMapper.selectAll();
         System.out.println("加载其余数据源配置列表: " + datasourceConfigs);
+        // 将数据库配置加入缓存
         datasourceConfigs.forEach(config -> DatasourceConfigCache.INSTANCE.addConfig(config.getId(), config));
     }
 }

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/annotation/DefaultDatasource.java

@@ -4,7 +4,7 @@ import java.lang.annotation.*;
 
 /**
  * <p>
- * 默认数据源
+ * 用户标识仅可以使用默认数据源
  * </p>
  *
  * @author yangkai.shen

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/aspect/DatasourceSelectorAspect.java

@@ -37,7 +37,7 @@ public class DatasourceSelectorAspect {
     }
 
     /**
-     * 前置通知 用于拦截操作
+     * 前置操作，拦截具体请求，获取header里的数据源id，设置线程变量里，用于后续切换数据源
      */
     @Before("datasourcePointcut()")
     public void doBefore(JoinPoint joinPoint) {
@@ -45,6 +45,7 @@ public class DatasourceSelectorAspect {
         MethodSignature methodSignature = (MethodSignature) signature;
         Method method = methodSignature.getMethod();
 
+        // 排除不可切换数据源的方法
         DefaultDatasource annotation = method.getAnnotation(DefaultDatasource.class);
         if (null != annotation) {
             DatasourceConfigContextHolder.setDefaultDatasource();
@@ -62,6 +63,9 @@ public class DatasourceSelectorAspect {
         }
     }
 
+    /**
+     * 后置操作，设置回默认的数据源id
+     */
     @AfterReturning("datasourcePointcut()")
     public void doAfter() {
         DatasourceConfigContextHolder.setDefaultDatasource();

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/config/MybatisConfiguration.java

@@ -19,7 +19,7 @@ import javax.sql.DataSource;
  * @date Created in 2019/9/4 16:20
  */
 @Configuration
-@MapperScan(basePackages = "com.xkcoding.dynamicdatasource.mapper", sqlSessionFactoryRef = "sqlSessionFactory")
+@MapperScan(basePackages = "com.xkcoding.dynamic.datasource.mapper", sqlSessionFactoryRef = "sqlSessionFactory")
 public class MybatisConfiguration {
     /**
      * 创建会话工厂。

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/datasource/DynamicDataSource.java

@@ -33,17 +33,24 @@ public class DynamicDataSource extends HikariDataSource {
         return datasource.getConnection();
     }
 
+    /**
+     * 初始化数据源
+     * @param id 数据源id
+     * @return 数据源
+     */
     private HikariDataSource initDatasource(Long id) {
         HikariDataSource dataSource = new HikariDataSource();
 
+        // 判断是否是默认数据源
         if (DatasourceHolder.DEFAULT_ID.equals(id)) {
+            // 默认数据源根据 application.yml 配置的生成
             DataSourceProperties properties = SpringUtil.getBean(DataSourceProperties.class);
             dataSource.setJdbcUrl(properties.getUrl());
             dataSource.setUsername(properties.getUsername());
             dataSource.setPassword(properties.getPassword());
             dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
         } else {
-            // 获取数据库的配置
+            // 不是默认数据源，通过缓存获取对应id的数据源的配置
             DatasourceConfig datasourceConfig = DatasourceConfigCache.INSTANCE.getConfig(id);
 
             if (datasourceConfig == null) {
@@ -55,6 +62,7 @@ public class DynamicDataSource extends HikariDataSource {
             dataSource.setPassword(datasourceConfig.getPassword());
             dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
         }
+        // 将创建的数据源添加到数据源管理器中，绑定当前线程
         DatasourceHolder.INSTANCE.addDatasource(id, dataSource);
         return dataSource;
     }

spring-boot-demo-dynamic-datasource/src/main/java/com/xkcoding/dynamic/datasource/mapper/UserMapper.java

@@ -2,6 +2,7 @@ package com.xkcoding.dynamic.datasource.mapper;
 
 import com.xkcoding.dynamic.datasource.config.MyMapper;
 import com.xkcoding.dynamic.datasource.model.User;
+import org.apache.ibatis.annotations.Mapper;
 
 /**
  * <p>
@@ -11,5 +12,6 @@ import com.xkcoding.dynamic.datasource.model.User;
  * @author yangkai.shen
  * @date Created in 2019/9/4 16:49
  */
+@Mapper
 public interface UserMapper extends MyMapper<User> {
 }