java源码。能够写出上面的代码，对于一个程序员只能说只是达到了最基本的要求，对于一个程序员来说，最重要的是执着，耐心和锲而不舍。-java source code. Can write the above code, a programmer can only say that for just reached the minimum requirements, for a programmer, the most important thing is perseverance, patien