First commit

src/main/java/link/at17/mid/tushare/component/ConfigAutoRegistrar.java

@@ -0,0 +1,74 @@
+package link.at17.mid.tushare.component;
+
+import org.apache.commons.lang3.StringUtils;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
+import org.springframework.context.annotation.DependsOn;
+import org.springframework.core.type.filter.AnnotationTypeFilter;
+import org.springframework.core.type.filter.AssignableTypeFilter;
+
+import link.at17.mid.tushare.annotation.ConfigInfo;
+import link.at17.mid.tushare.interfaces.IConfig;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * 实现自动化注册 Config
+ */
+@Slf4j
+@DependsOn("configService")
+public class ConfigAutoRegistrar implements BeanDefinitionRegistryPostProcessor {
+
+    @Override
+    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
+        ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(false);
+        scanner.addIncludeFilter(new AssignableTypeFilter(IConfig.class));
+        scanner.addIncludeFilter(new AnnotationTypeFilter(ConfigInfo.class));
+
+        scanner.findCandidateComponents("link.at17.mid.tushare.system.config").forEach(beanDefinition -> {
+            String className = beanDefinition.getBeanClassName();
+            try {
+                // 确保其 field 规则与 configService 内 field 生成规则一致，即：
+                // 如果 @ConfigInfo 指定了 field 的，使用该 field + "Config"
+                // 作为 beanName，否则使用首字母小写的 simpleClassName 作为
+                // beanName，且 simpleClassName 无论如何必须以 Config 作为结尾。
+                Class<?> clazz = Class.forName(className);
+                String beanName = clazz.getSimpleName().substring(0, 1).toLowerCase()
+                        + clazz.getSimpleName().substring(1);
+
+                if (!IConfig.class.isAssignableFrom(clazz)) {
+                    log.warn("Config {} does not implement IConfig, ignore", beanName);
+                    return;
+                }
+                
+                if (!beanName.endsWith("Config")) {
+                    log.warn("Config {}'s simple class name does not end with \"Config\", ignore", beanName);
+                    return;
+                }
+                
+                ConfigInfo info = clazz.getAnnotation(ConfigInfo.class);
+                if (info == null) {
+                    log.warn("Config {} does not have @ConfigInfo annotation, ignore", clazz.getName());
+                    return;
+                }
+                if (StringUtils.isNotBlank(info.field())) {
+                    beanName = info.field() + "Config";
+                }
+                
+                BeanDefinitionBuilder factoryBean = BeanDefinitionBuilder
+                        .genericBeanDefinition(ConfigServiceFactoryBean.class)
+                        .addConstructorArgValue(clazz);
+                // 注意此处注册 factoryBean 不意味着 FactoryBean.getObject() 方法立即被执行，
+                // Spring 管理的 Bean 默认在其被使用时才创建，所以如果 getObject() 调用一些方
+                // 法，这些方法会在初次使用 Bean 时才被创建。如果这些方法对于启动过程很重要，
+                // 需要在对应 Config(Bean) 上加上 @Bean 和 @Lazy(false) 注解，确保一旦准备好
+                // 相应的 Bean 就会被创建。
+                registry.registerBeanDefinition(beanName, factoryBean.getBeanDefinition());
+                log.info("Add config {} to bean register", beanName);
+            } catch (ClassNotFoundException e) {
+                throw new RuntimeException("Failed to load class: " + className, e);
+            }
+        });
+    }
+}