feat: 添加数据源配置类，解析并配置动态数据源

Author: cadecode

simple-common/src/main/java/top/cadecode/common/config/DataSourceConfig.java

@@ -0,0 +1,97 @@
+package top.cadecode.common.config;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.mybatis.spring.annotation.MapperScan;
+import org.springframework.beans.factory.config.YamlMapFactoryBean;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+import org.springframework.core.io.ClassPathResource;
+import top.cadecode.common.datasource.DynamicDataSource;
+import top.cadecode.common.datasource.DynamicDataSource.DynamicDataSourceHolder;
+
+import javax.sql.DataSource;
+import java.util.*;
+
+/**
+ * @author Li Jun
+ * @date 2021/12/3
+ * @description 数据源配置类
+ */
+@Slf4j
+@Configuration
+@MapperScan({"top.cadecode.model"})
+@RequiredArgsConstructor
+public class DataSourceConfig {
+
+    private final Environment environment;
+
+    @Bean
+    public DynamicDataSource dynamicDataSource() {
+        log.info("配置动态数据源");
+        DynamicDataSource dynamicDataSource = new DynamicDataSource();
+        // 读取 dataSource.yml
+        YamlMapFactoryBean dateSourceMapFactory = new YamlMapFactoryBean();
+        dateSourceMapFactory.setResources(new ClassPathResource("dataSource.yml"));
+        Map<String, Object> dataSourceMap = dateSourceMapFactory.getObject();
+        // 获取所有数据源 key
+        Set<String> keys = dataSourceMap.keySet();
+        // 存储 keys 到 DynamicDataSourceHolder
+        DynamicDataSourceHolder.addDataSourceKeys(keys);
+        // 定义数据源容器，用于设置到 dynamicDataSource
+        Map<Object, Object> targetDataSourceMap = new HashMap<>();
+        // 遍历 keys
+        keys.forEach(key -> {
+            log.info("解析数据源配置 " + key);
+            Map<String, Object> configMap = this.checkDataSourceMap(dataSourceMap, key);
+            // 取出数据源类型和 isDefault
+            String type = (String) configMap.get("type");
+            Boolean isDefault = (Boolean) configMap.get("isDefault");
+            // 生成数据源实例
+            DataSource dataSource = (DataSource) Binder.get(environment)
+                    .bind(key + ".config", this.checkDataSourceType(type, key)).get();
+            targetDataSourceMap.put(key, dataSource);
+            // 判断是否是默认数据源
+            if (isDefault != null && isDefault.equals(true) && !dynamicDataSource.hasDefaultDataSource()) {
+                dynamicDataSource.setDefaultTargetDataSource(dataSource);
+                log.info("设置默认数据源为 " + key);
+            }
+        });
+        // 判断是否设置默认数据源
+        if (!dynamicDataSource.hasDefaultDataSource()) {
+            throw new IllegalArgumentException("未指定默认数据源，使用 isDefault: true 指定");
+        }
+        // 设置数据源到 dynamicDataSource
+        dynamicDataSource.setTargetDataSources(targetDataSourceMap);
+        return dynamicDataSource;
+    }
+
+    /**
+     * 校验 dataSourceMap
+     */
+    private Map<String, Object> checkDataSourceMap(Map<String, Object> dataSourceMap, String key) {
+        if (dataSourceMap.get(key) == null || !(dataSourceMap.get(key) instanceof Map)) {
+            throw new IllegalArgumentException("数据源 " + key + " 配置有误，无法解析");
+        }
+        return (Map<String, Object>) dataSourceMap.get(key);
+    }
+
+    /**
+     * 获取数据源 class
+     */
+    private Class<?> checkDataSourceType(String type, String key) {
+        Class<?> dataSourceClass;
+        try {
+            dataSourceClass = Class.forName(type);
+            // 判断是否是 DataSource 类型
+            if (!DataSource.class.isAssignableFrom(dataSourceClass)) {
+                throw new IllegalArgumentException("数据源 " + key + " 的类型 " + type + " 不合适");
+            }
+        } catch (ClassNotFoundException e) {
+            throw new IllegalArgumentException("数据源 " + key + " 的类型 " + type + " 不存在");
+        }
+        return dataSourceClass;
+    }
+}