开心激情五月天

This is very understandable. The purpose of the command mode is to decouple the sender and executor of the command and separate the request from the execution. Students familiar with Struts should know that Struts is actually a technology that separates the request from the presentation, which inevitably involves the idea of the command mode!Liskov Substitution Principle, LSP (Richter Substitution Principle) means that subclasses must replace their parent types. In other words, in the process of software development, after the subclass replaces the parent class, the behavior of the program is the same. Only when the subclass replaces the parent class and the function of the software is not affected can the parent class be truly reused, and the subclass can also add new behaviors to the parent class. In order to look at an example of violation of LSP principles, the specific code is as follows:　　终于，三个孩子的亲生父母相继现身，而他们又经历了各自的辛酸苦辣。总是你我没有血缘关系，但我们的亲情早已胜过一切……　　刚刚18岁的大姑娘方瑾，为了家中病重的父亲，为了弟妹们能有口饭吃，不再受苦，只有和自己的心上人高可可西里，包括西藏北部被称为“羌塘草原”的部分、青海昆仑山以南地区和新疆的同西藏、青海毗邻的地区；可可西里自然保护区位于青海西南部的玉树藏族自治州境内，面积4.5万平方公里；同时可可西里也是导演陆川的一部反映可可西里自然保护区的电影。正沉吟间，就听张杨问道：白大人真的是从梅县城外的河边找回他的？大苞谷大叫道：他撒谎。杨长帆抱着翘儿悄声道，这梦，始终是咱们的，绝不会有第三个人。