[Java] 패키지 탐색하기~!

Java에서 Reflection을 편리하게? 사용하기 위한 라이브러리가 있다. 아래와 같이 사용하면 된다.~!

1. 라이브러리 추가

<dependency>
      <groupId>org.reflections</groupId>
      <artifactId>reflections</artifactId>
      <version>0.9.9-RC1</version>
</dependency>

2. 사용법

Reflections reflections = new Reflections("my.project.prefix");

     Set<Class<? extends SomeType>> subTypes = 
               reflections.getSubTypesOf(SomeType.class);

     Set<Class<?>> annotated = 
               reflections.getTypesAnnotatedWith(SomeAnnotation.class);

 Reflections reflections = new Reflections("my.package.prefix");
     //or
     Reflections reflections = new Reflections(ClasspathHelper.forPackage("my.package.prefix"), 
          new SubTypesScanner(), new TypesAnnotationScanner(), new FilterBuilder().includePackage(...), ...);

     //or using the ConfigurationBuilder
     new Reflections(new ConfigurationBuilder()
          .filterInputsBy(new FilterBuilder().includePackage("my.project.prefix"))
          .setUrls(ClasspathHelper.forPackage("my.project.prefix"))
          .setScanners(new SubTypesScanner(), new TypeAnnotationsScanner().filterResultsBy(optionalFilter), ...));

     //then query, for example:
     Set<Class<? extends Module>> modules = reflections.getSubTypesOf(com.google.inject.Module.class);
     Set<Class<?>> singletons =             reflections.getTypesAnnotatedWith(javax.inject.Singleton.class);
     
     Set<String> properties =       reflections.getResources(Pattern.compile(".*\\.properties"));
     Set<Constructor> injectables = reflections.getConstructorsAnnotatedWith(javax.inject.Inject.class);
     Set<Method> deprecateds =      reflections.getMethodsAnnotatedWith(javax.ws.rs.Path.class);
     Set<Field> ids =               reflections.getFieldsAnnotatedWith(javax.persistence.Id.class);

     Set<Method> someMethods =      reflections.getMethodsMatchParams(long.class, int.class);
     Set<Method> voidMethods =      reflections.getMethodsReturn(void.class);
     Set<Method> pathParamMethods = reflections.getMethodsWithAnyParamAnnotated(PathParam.class);
     Set<Method> floatToString =    reflections.getConverters(Float.class, String.class);