装饰器模式.java

// 应该可以为接口或是抽象类
interface Component {
  Object operate();
}

class ComponentImpl {
  Object operate() { }
}

// 实现接口或是抽象类
class ComponentDecarator implement Component {
  Component component;
  ComponentDecarator(Component _component) {
    component = _component
  }
  
  @Override
  Object operate() {
    Object obj = component.operate();
    this.doSomething();
    return obj;
  }
  
}