因为声明的顺序和徐老师不一样 private Component dependencyComponent; private Component componentComponent; 导致自动生成构造函数的参数顺序也不一样，查了半天，哈哈 public DependencyNotFoundException(Component dependencyComponent, Component componentComponent) { this.dependencyComponent= dependencyComponent; this.componentComponent= componentComponent; } 这个是错误的版本