Dear Planet Java programmers brothers:
Hello! I am a Java programmer from Earth, Earth First, on behalf of your high commander of the planet came to Earth to teach Java language, for the benefit of all mankind, for the benefit of the entire planet to express my sincere thanks!
Remember the high commander first came to Earth, he does not speak Mandarin Chinese, could not speak English, one of the international lingua franca, in order to talk to people on earth normal communication, he decided to teach their people the planet Earth Java language. Considering the human race from an early age to learn their mother tongue, and suddenly learning a new language is certainly difficult. Java can be used as elite planets, James Gosling considered methods better than more difficult.
Before the high commander to observe the child has not officially go to school, we have been able to understand so many things to learn Chinese after he certainly is helpful. He felt that he could do this, put these simple concepts Java language the most simple variables, constants, data types, and speak to the human, so that human understanding of these things, over time, like a child would say simple words like break out of. After then, we can further increase the difficulty, teach human understanding "object-oriented", for this, they grew to know "people in groups feather flock together," and then come back to understand the "object" is not hard, Java language is "life is full of all objects," from childhood by the object class awareness, and the link between Java classes recognized by the object, is very close to the target as long as people have a certain understanding, learning Java language is no longer a difficult thing.
"No rules, no set blueprints", Chinese have Chinese "rules", which rules the children need to go to school to learn a professional system of. We continue to say that the child I mentioned above it, and he was learning with parents the Qinghai dialect, in elementary school, the teacher asked the school not say "native dialect", and should speak Mandarin official regulations, and patiently teaching them the law say Mandarin. Children learn very seriously, phonetic grasp well, naturally speak Mandarin nothing wrong. Later the teacher took the children to learn Chinese characters, from easy to difficult, from entry to the master, the students while being read to write, learning the whole day. Over time, the child will be able to write some commonly used Chinese characters, a child my father taught his cats and dogs, elephants, tigers he would write a small Yin very happy, learning more and more interested.
High school commander saw Seohyun so well, inspired, he is also well aware of the Java language Java language "rules", such as variable before it comes in, although variable understand the very simple, but there are rules, not the variable name start with a number, is case sensitive, so are the rules hump nomenclature, the human need to "train" high commander of the professional system. And other humans know some basic rules, the high commander with humans practice, with a kind of sacred ritual with a sense of humanity output the first sentence of the Java language "in the computer the Hello World ." Since then, some simple output to humans is no longer a problem, variables, constants, data types, operators, etc. can skillfully use, rules and practices complement each other, easy to use.
Chinese culture is profound, Junior strong, the country strong, for the country more prosperous, Chinese people worked hard, study hard, small Yin is no exception, after he learned to write, the teacher gave them teach group of words, idioms teach, teach sentences , to teach poetry, this process has a problem, a lot of kids do not know the word, but it does not matter, the teacher responsible to teach them the dictionary, are all learning rhythmic, smooth writing. Still later teach kids writing, writing poetry when more appropriate reference may be good sentence, quote, the higher the quality of writing. High commander to see this, are not quoted Zhou Enlai's words, "the rise of the China study," children, refueling.
All things are connected, you're going to find the meaning behind, which the law, and now I do not have this ability, but not the same high commander, group of words to see the children learn, learning idioms, sentences to learn, learn poetry thus he taught human language Java in process control, arrays, functions, in fact, not difficult to understand, because they are based on the rules before, and now just use, streamlined package, in order to form a more perfect practice. Object-oriented before humans have a certain understanding, and now some of them talk about deep, they can understand, the three characteristics of object-oriented encapsulation, inheritance, polymorphism, and then to grasp learned from the master, the essence of the Java language has slowly It flows into the mind of a human. The children write poems give references add luster to the article, Java language is also the same token, in the form of object-oriented class show, you can play in the unlimited class, the reasonable use of the function, precise process control and use an array of fine and Jane, "high cohesion, low coupling" is the plus point of the Java language. Class can be packaged, classification, can be reused. When children learn poetry poetry division, which for the first reference to it in which the first article, Java language, too, was doing the project, which will import the class for which class, then the question is, so many classes, how You know which class to use it? The high commander has long been thought to us, we are ready to give the API documentation, almost a child with the dictionary meaning, but each check required nothing more. Children can not read to check the Xinhua Dictionary, Java programmers do not know which class to import, you check the API documentation. This can be learned after originally thought the class was over, but the high commander enough, say Java language forms, meaningful, and so you learn the notes and reflections on more experience, and later commander of the human listen high notes and reflective finish , could not help lamenting, good magic ah.
千秋无绝色！悦目是佳人！倾国倾城貌！惊为天下人！对于“美”大家都是喜欢的，"美"有很多种表达形式，美术是其中一种。孩子们也学美术，还记得小贤吗，他对“美”的要求是很高的，他喜欢画画，画的也确实不错，有板有眼，惟妙惟肖，值得称赞。但是如果把这些美的东西放到文章中去，就没有那么简单了，因为要考虑的东西很多，排版、读者的感受等等你都要考虑，不过小贤基本功扎实，这些问题对小贤来说也就不是问题了。从写文章，到文章的美化，小贤都是行云流水般一气呵成，堪称奇才。
高司令也是个爱“美”的人，虽然那些表达“美”的方式和地球上不一样，高司令是个全才，除了Java语言之外，他还会HTML,CSS,JavaScript等语言，这三种语言也是表达“美”的一种形式，HTML和CSS展示静态美，JavaScript展示动态美。高司令是个乐于分享的人，他相信“越懂得分享，你的价值增值越大”，这就是他来地球的使命。高司令又要开课了，把这三个“美”的艺术教给了人类，人类用它们做出了很多炫酷的作品。小贤凭着他的基本功和审美标准，能把文章和相应的美化装饰完美的结合起来，但是要想把用Java语言完成的项目进行美化装饰，可没这么简单，中间得有个过度，Servlet就是将Java后端和前端进行衔接的桥梁，Servlet其实是在服务器上运行的小程序，说白了就是一个Java类，只不过这个类比较特殊，既然比较特殊就肯定要特殊照顾了。为何特殊呢？刚说过了啊，桥梁嘛，客户端发出的请求会交给Servlet处理，等Servlet处理完后又要由它做出响应。不过万事万物“有利必有弊”，Servlet的弊端就在于它在完成响应的时候描述太复杂了，需要写很多代码，哈哈，还有一句叫“有因必有果”，既然麻烦，那就换个不麻烦的。JSP,它能很好的解决“麻烦”，JSP其实也是一个Servlet,只是它俩功能有些差别，Servlet擅长于处理后端数据，JSP擅长于完成前端响应，如果能合理应用它俩，那就锦上添花了。说到JSP,高司令又多说了点，他说在用JSP的时候，你要是能用EL表达式，JSP的代码就更简洁了，EL表达式就是为了使JSP写起来更加简单。
中华汉字那么多，要想全部记住是不可能的，最好的方法就是把所有的汉字都“存储”到字典中，等到我们忘了的时候可以查阅字典重新记忆。高司令对人类说：“在用编程语言做项目的过程中，也需要存储大量的数据，而且这很重要，等你们能用编程语言进行编程后，会经常对数据进行存储操作，用Java编程语言存储的数据可不是放在字典中了，而是放在‘数据库’中，一般情况下我们常用的数据库有两种，一种叫MySQL，另一种叫Oracle,你可以选择其中的一种进行数据的存储。不过需要注意的是，不论你选择哪一种，你在存储数据的时候都要用到一套操作数据库的标准规范叫JDBC。如果没有JDBC,可能你要用MySQL，你就需要用操作MySQL所对应的操作步骤，用Oracle，就又要考虑用操作Oracle所对应的操作步骤，但有了JDBC,存储数据就不用考虑那么多了，不管你用哪个数据库，就只有JDBC这一套操作步骤，省力省时间，何乐而不为。”
“昨夜江边春水生，艨艟巨舰一毛轻。向来枉费推移力，此日中流自在行”。人们对“效率”的要求似乎一直是只高不低，尤其生活在大城市的人们，每天都在过快节奏的生活，每个人都争分夺秒，一刻都不敢停下来。再看小贤，如今的小贤已经能独当一面了，写文章不在话下，不过现在他也在追求所谓的“效率”，凭着他扎实的基本功和多年写文章的经验积累，他为自己设计了几套“模版”，假如他要写信，就有专门的书信模版，要写作文，也有相对应类型的作文模版，有的模版是按总分总形式写的，开头和结尾部分都已经写好了，写的时候只需要把内容写进去即可。就问你服不服，效率高不高，别人吭哧吭哧写半天，小贤手到拈来，高司令看了不由感叹，“青出于蓝而胜于蓝”啊！
不过人类学编程的速度也是够快了，在高司令的耐心教导下，他们都能独立完成完整的项目了。人类现在考虑的也是“效率”问题，他们每天研究如何快速开发一个项目。高司令看时机成熟，在人类最需要他的时候出现了，他一出现就直奔主题，对人类说：“如今你们技术小成，我很欣慰，为了表示奖励，我决定帮你们解决你们近日苦思的问题。我最近看到你们在写作文的时候有一些相对应的作文模板，其实今天我教你们的东西跟这个模板是一个意思，首先说一个概念叫JSTL,也叫JSP标准标签库，它的作用就是能让你们这些开发人员利用它的标签取代JSP页面上的Java代码，其实就是让你们根据需求自定义模板，等到你再做开发时，你就可以根据项目需求选择合适的模板，选好后就可以直接套用模板，而不用再重复去写了。所以你们现在会比之前多一些选择，你们开发项目的时候可以选择用别人的模板，也可以自定义模板，这样就能增加开发效率，这个模板也叫框架，就是名字不一样，但涵义是一样的。”人类听完，很兴奋也很激动，此后不断努力研究，最终，好多各种著名的框架横空出世，有Spring,SpringMVC,Mybatis(也称SSM),Struts,Hibernate(也称SSH)，还有SpringBoot等多种框架，被后面的人广泛应用，已成佳话。
“万丈高楼平地起”，就这样，高司令费尽心思把这笔知识财富留给了人类，最后腾空而起，在人类“风萧萧兮易水寒，壮士一去兮不复还”的悲调中消失，回到了Java星球，成为地球人心中最美的太阳。
备注：在此声明文中的高司令只是虚构人物，非Java之父“高司令”
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Java学习路线：【学习目录及学习资源获取】
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【原创声明】：此篇由泰斗贤若如所作，来源：https://www.cnblogs.com/zyx110/