go知识重新整理

Go/DesignPattern/observer/observer.go

@@ -0,0 +1,51 @@
+package observer
+
+import "fmt"
+
+//观察者模式：用于触发联动，一个对象的改变会触发其他观察者的相关动作，而此对象无需关心联动对象的具体实现
+
+func NewSubject() *Subject {
+	return &Subject{
+		observers: make([]Observer, 0),
+	}
+}
+
+type Subject struct {
+	observers []Observer
+	context   string
+}
+
+type Observer interface {
+	Update(*Subject)
+}
+
+func (s *Subject) Attach(o Observer) {
+	s.observers = append(s.observers, o)
+}
+
+//notify every observers
+func (s *Subject) notify() {
+	for _, o := range s.observers {
+		o.Update(s)
+	}
+}
+
+func (s *Subject) UpdateContext(context string) {
+	s.context = context
+	//notify all observers
+	s.notify()
+}
+
+func NewReader(name string) *Reader {
+	return &Reader{
+		name: name,
+	}
+}
+
+type Reader struct {
+	name string
+}
+
+func (r *Reader) Update(s *Subject) {
+	fmt.Printf("%s receive %s\n", r.name, s.context)
+}