求Spring Modulith中ApplicationModuleDetectionStrategy接口实现示例

Spring Modulith的ApplicationModuleDetectionStrategy接口用于自定义模块的检测逻辑，可替代默认的包结构检测规则。下面是两个实用的实现示例：

示例1：基于指定包前缀的模块检测 #

此实现会将所有以com.myapp.module.开头的子包识别为独立模块：

import org.springframework.modulith.core.ApplicationModule;
import org.springframework.modulith.core.ApplicationModuleDetectionStrategy;
import org.springframework.modulith.core.NamedInterface;
import org.springframework.modulith.core.Types;

import java.util.Set;
import java.util.stream.Collectors;

public class PrefixBasedModuleDetectionStrategy implements ApplicationModuleDetectionStrategy {

    private static final String MODULE_PREFIX = "com.myapp.module.";

    @Override
    public Set<ApplicationModule> detect(Types types) {
        // 过滤符合前缀的包，每个包对应一个模块
        return types.getTypesByPackage()
                .keySet()
                .stream()
                .filter(pkg -> pkg.startsWith(MODULE_PREFIX))
                .map(pkg -> ApplicationModule.of(pkg, types))
                .collect(Collectors.toSet());
    }

    @Override
    public Set<NamedInterface> detectNamedInterfaces(ApplicationModule module) {
        // 将模块下的api子包标记为公开接口
        return module.getPackage()
                .getSubpackages("api")
                .stream()
                .map(subpkg -> NamedInterface.of("api", subpkg))
                .collect(Collectors.toSet());
    }
}

示例2：基于类注解的模块检测 #

此实现会将包含自定义@MyModule注解的类所在包识别为模块：

import org.springframework.modulith.core.ApplicationModule;
import org.springframework.modulith.core.ApplicationModuleDetectionStrategy;
import org.springframework.modulith.core.NamedInterface;
import org.springframework.modulith.core.Types;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.Set;
import java.util.stream.Collectors;

// 自定义模块标记注解
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyModule {}

// 检测策略实现
public class AnnotationBasedModuleDetectionStrategy implements ApplicationModuleDetectionStrategy {

    @Override
    public Set<ApplicationModule> detect(Types types) {
        // 提取所有标注@MyModule的类所在包，去重后生成模块
        return types.getTypesAnnotatedWith(MyModule.class)
                .stream()
                .map(type -> type.getPackage())
                .distinct()
                .map(pkg -> ApplicationModule.of(pkg, types))
                .collect(Collectors.toSet());
    }

    @Override
    public Set<NamedInterface> detectNamedInterfaces(ApplicationModule module) {
        // 将模块根包作为默认公开接口
        return Set.of(NamedInterface.of("public", module.getPackage()));
    }
}

启用自定义策略 #

在Spring Boot应用中，只需将自定义策略类注册为Spring Bean即可生效：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ModulithConfig {

    @Bean
    public ApplicationModuleDetectionStrategy customModuleDetectionStrategy() {
        return new PrefixBasedModuleDetectionStrategy(); // 可替换为AnnotationBasedModuleDetectionStrategy
    }
}

内容的提问来源于stack exchange，提问作者Diferdin