public class SubjectOberser{
  private String subjectKey;
  private AbstractObserver abstractObserver;
  ...geter seter 方法...
 } 

 public interface Collector<T, A, R> { 
   Supplier<A> supplier();
   BiConsumer<A, T> accumulator();
   Function<A, R> finisher();
   BinaryOperator<A> combiner();
   Set<Characteristics> characteristics();
 }

 public BiConsumer<Map<String, List<AbstractObserver>>, SubjectObserver> accumulator() {
  return (Map<String, List<AbstractObserver>> acc, SubjectObserver v) -> {
   if (acc.containsKey(v.getSubjectKey())){
    acc.get(v.getSubjectKey()).add(v.getAbstractObserver());
   }else{
    List<AbstractObserver> l = new ArrayList<>();
    l.add(v.getAbstractObserver());
    acc.put(v.getSubjectKey(),l);
   }
  };
 }

 public Function<Map<String, List<AbstractObserver>>,
     Map<String, List<AbstractObserver>>> finisher(){
   return Function.identity();
 }

  public BinaryOperator<Map<String, List<AbstractObserver>>> combiner() {
  return ((Map<String, List<AbstractObserver>> map1, 
    Map<String, List<AbstractObserver>> map2) -> {
     map1.putAll(map2);
     return map1;
   });
 }

   public Set<Characteristics> characteristics() {
    return Collections.unmodifiableSet(EnumSet.of(Characteristics.IDENTITY_FINISH));
   }

 public class MyCollector implements Collector<SubjectObserver,
  Map<String, List<AbstractObserver>>,
  Map<String, List<AbstractObserver>>> {


  @Override
  public Supplier<Map<String, List<AbstractObserver>>> supplier() {
   return () -> new HashMap<>();
  }

  @Override
  public BiConsumer<Map<String, List<AbstractObserver>>, SubjectObserver> accumulator() {
   return (Map<String, List<AbstractObserver>> acc, SubjectObserver v) -> {
    if (acc.containsKey(v.getSubjectKey())) {
     acc.get(v.getSubjectKey()).add(v.getAbstractObserver());
    } else {
     List<AbstractObserver> l = new ArrayList<>();
     l.add(v.getAbstractObserver());
     acc.put(v.getSubjectKey(), l);
    }
   };
  }

  @Override
  public BinaryOperator<Map<String, List<AbstractObserver>>> combiner() {
   return ((Map<String, List<AbstractObserver>> map1, Map<String, List<AbstractObserver>> map2) -> {
    map1.putAll(map2);
    return map1;
   });
  }

  @Override
  public Function<Map<String, List<AbstractObserver>>, Map<String, List<AbstractObserver>>> finisher() {
   return Function.identity();
  }

  @Override
  public Set<Characteristics> characteristics() {
   return Collections.unmodifiableSet(EnumSet.of(Characteristics.IDENTITY_FINISH));
  }
 }

 public static Map<String, List<AbstractObserver>> initObjectMap() {
 ClassScaner classScaner = new ClassScaner();
 Set<Class> set = classScaner.doScan("com.souche.datacenter.observer");
 return set
   .stream()
   .filter(aClass -> SubjectAnnotationResolver.getAnnotationSubjectName(aClass) != null)
   .map(aClass -> {
    String subjectKey = SubjectAnnotationResolver.getAnnotationSubjectName(aClass);
    AbstractObserver abstractObserver = getBeanByClassName(aClass.getSimpleName());
    return new SubjectObserver(subjectKey, abstractObserver);
   }).collect(new MyCollector());
 }