增加 apollo 读取本地 db，需要进一步优化~

src/main/java/cn/iocoder/dashboard/framework/apollo/internals/DBConfigRepository.java

@@ -1,5 +1,8 @@
 package cn.iocoder.dashboard.framework.apollo.internals;
 
+import cn.hutool.core.collection.CollUtil;
+import cn.iocoder.dashboard.framework.mybatis.core.dataobject.BaseDO;
+import cn.iocoder.dashboard.modules.system.dal.mysql.dataobject.config.SysConfigDO;
 import com.ctrip.framework.apollo.Apollo;
 import com.ctrip.framework.apollo.build.ApolloInjector;
 import com.ctrip.framework.apollo.core.utils.ApolloThreadFactory;
@@ -8,13 +11,20 @@ import com.ctrip.framework.apollo.internals.AbstractConfigRepository;
 import com.ctrip.framework.apollo.internals.ConfigRepository;
 import com.ctrip.framework.apollo.tracer.Tracer;
 import com.ctrip.framework.apollo.util.ConfigUtil;
+import com.ctrip.framework.apollo.util.factory.PropertiesFactory;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.jdbc.core.BeanPropertyRowMapper;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
 
+import javax.sql.DataSource;
+import java.sql.ResultSet;
+import java.util.Comparator;
+import java.util.Date;
+import java.util.List;
 import java.util.Properties;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicReference;
 
 @Slf4j
 public class DBConfigRepository extends AbstractConfigRepository {
@@ -27,15 +37,35 @@ public class DBConfigRepository extends AbstractConfigRepository {
     }
 
     private final ConfigUtil m_configUtil;
-
-    private final AtomicReference<Properties> m_configCache;
+    private PropertiesFactory propertiesFactory;
     private final String m_namespace;
 
+    /**
+     * 配置缓存，使用 Properties 存储
+     */
+    private volatile Properties m_configCache;
+    /**
+     * 缓存配置的最大更新时间，用于后续的增量轮询，判断是否有更新
+     */
+    private volatile Date maxUpdateTime;
+
+    /**
+     * Spring JDBC 操作模板
+     */
+    private final JdbcTemplate jdbcTemplate;
+
     public DBConfigRepository(String namespace) {
         // 初始化变量
         this.m_namespace = namespace;
-        m_configCache = new AtomicReference<>();
-        m_configUtil = ApolloInjector.getInstance(ConfigUtil.class);
+        this.propertiesFactory = ApolloInjector.getInstance(PropertiesFactory.class);
+        this.m_configUtil = ApolloInjector.getInstance(ConfigUtil.class);
+        // TODO 优化到配置
+        String url = "jdbc:mysql://127.0.1:33061/ruoyi-vue-pro?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=CTT";
+        String username = "root";
+        String password = "123456";
+//        DataSource dataSource = DataSourceBuilder.create().url(url).username(username).password(password).build();
+        DataSource dataSource = new DriverManagerDataSource(url, username, password);
+        this.jdbcTemplate = new JdbcTemplate(dataSource);
 
         // 初始化加载
         this.trySync();
@@ -43,27 +73,32 @@ public class DBConfigRepository extends AbstractConfigRepository {
         this.schedulePeriodicRefresh();
     }
 
-    private AtomicInteger index = new AtomicInteger();
-
     @Override
     protected void sync() {
-        System.out.println("我同步啦");
+        // 第一步，尝试获取配置
+        List<SysConfigDO> configs = this.loadConfigIfUpdate(this.maxUpdateTime);
+        if (CollUtil.isEmpty(configs)) { // 如果没有更新，则返回
+            return;
+        }
+        log.info("[sync][同步到新配置，配置数量为:{}]", configs.size());
 
-        index.incrementAndGet();
-        Properties properties = new Properties();
-        properties.setProperty("demo.test", String.valueOf(index.get()));
-        m_configCache.set(properties);
-        super.fireRepositoryChange(m_namespace, properties);
+        // 第二步，构建新的 Properties
+        Properties newProperties = this.buildProperties(configs);
+        this.m_configCache = newProperties;
+        // 第三步，获取最大的配置时间
+        this.maxUpdateTime = configs.stream().max(Comparator.comparing(BaseDO::getUpdateTime)).get().getUpdateTime();
+        // 第四部，触发配置刷新！重要！！！！
+        super.fireRepositoryChange(m_namespace, newProperties);
     }
 
     @Override
     public Properties getConfig() {
         // 兜底，避免可能存在配置为 null 的情况
-        if (m_configCache.get() == null) {
+        if (m_configCache == null) {
             this.trySync();
         }
         // 返回配置
-        return m_configCache.get();
+        return m_configCache;
     }
 
     @Override
@@ -76,6 +111,15 @@ public class DBConfigRepository extends AbstractConfigRepository {
         return ConfigSourceType.REMOTE;
     }
 
+    private Properties buildProperties(List<SysConfigDO> configs) {
+        Properties properties = propertiesFactory.getPropertiesInstance();
+        configs.stream().filter(config -> 0 == config.getDeleted()) // 过滤掉被删除的配置
+                .forEach(config -> properties.put(config.getKey(), config.getValue()));
+        return properties;
+    }
+
+    // ========== 定时器相关操作 ==========
+
     private void schedulePeriodicRefresh() {
         log.debug("Schedule periodic refresh with interval: {} {}",
                 m_configUtil.getRefreshInterval(), m_configUtil.getRefreshIntervalTimeUnit());
@@ -83,7 +127,7 @@ public class DBConfigRepository extends AbstractConfigRepository {
             Tracer.logEvent("Apollo.ConfigService", String.format("periodicRefresh: %s", m_namespace));
             log.debug("refresh config for namespace: {}", m_namespace);
 
-            // 执行同步
+            // 执行同步. 内部已经 try catch 掉异常，无需在处理
             trySync();
 
             Tracer.logEvent("Apollo.Client.Version", Apollo.VERSION);
@@ -92,4 +136,35 @@ public class DBConfigRepository extends AbstractConfigRepository {
 //                TimeUnit.SECONDS);
     }
 
+    // ========== 数据库相关操作 ==========
+
+    /**
+     * 如果配置发生变化，从数据库中获取最新的全量配置。
+     * 如果未发生变化，则返回空
+     *
+     * @param maxUpdateTime 当前配置的最大更新时间
+     * @return 配置列表
+     */
+    private List<SysConfigDO> loadConfigIfUpdate(Date maxUpdateTime) {
+        // 第一步，判断是否要更新。
+        boolean isUpdate = maxUpdateTime == null; // 如果更新时间为空，说明 DB 一定有新数据
+        if (!isUpdate) {
+            isUpdate = this.existsNewConfig(maxUpdateTime); // 判断数据库中是否有更新的配置
+        }
+        if (!isUpdate) {
+            return null;
+        }
+        // 第二步，如果有更新，则从数据库加载所有配置
+        return this.getSysConfigList();
+    }
+
+    private boolean existsNewConfig(Date maxUpdateTime) {
+         return jdbcTemplate.query("SELECT id FROM sys_config WHERE update_time > ? LIMIT 1",
+                 ResultSet::next, maxUpdateTime);
+    }
+
+    private List<SysConfigDO> getSysConfigList() {
+        return jdbcTemplate.query("SELECT `key`, `value`, update_time, deleted FROM sys_config", new BeanPropertyRowMapper<>(SysConfigDO.class));
+    }
+
 }