整理了一下ppt的内容，java程序设计课程的课件。

软件开发(Software Development)

Agile Methodologies（敏捷方法）

这是一种快速部署应用程序的理念，优点包括：

  • persistent software delivery 持续提交软件

  • increased stakeholder satisfaction 增加利益方的满意度

  • inspect and adapt 检查调整

  • welcome to changes at any stage 支持任意阶段修改

  • design is important 设计至关重要

  • daily interaction 日常互动

版本控制（version control）

就是说需要一个git来控制一下版本，对多人合作很方便。而关于这个git的用法可以看看这篇博客 。

JVM

这里多说两句这个JVM，JVM（Java Virtucal Machine）是一个类似虚拟机的玩意，它运行在操作系统之下，通过与操作系统交互达到与硬件交互的目的。知道这个之后我们看看java文件怎么运行，首先写完一个.java文件之后通过编译器编译得到一个.class文件，然后通过类加载器把这个.class丢到JVM里面。这里再多提两句嘴，JVM内主要的五大块：方法区，堆是线程共享区域，有线程安全问题，栈和本地方法栈和计数器是独享区域，不存在线程安全问题。

Java语言基础

语言基础语法

这个去这里看。

UML图

呃就是一个类的图形化表示，举个例子吧~

递归

  • Mistakes like omitting the base case or writing the recursion step incorrectly can cause infinite recursion. 小心无限递归爆栈
  • Recursive programs may result in exponential method calls 递归可能导致指数级别调用
  • Each recursive method can be re-written using loops所有递归可重写为循环
  • Use recursive methods only if the problem is naturally recursive (i.e., to improve understanding) or there are performance benefits, or you need to impress in a job interview在必要的时候再用递归

Concurrency in Java （并发）

Complex applications may use multithreading to speed up performance or user experience 复杂的程序会使用多线程来加速性能或用户体验

Caveats of multithreading（多线程注意事项）

  • Calling methods from multiple threads may have undesired and unexpected side effects (things may not happen in the expected order) 可能有副作用
  • Only primitive variables that are declared final can be shared across threads 只有声明final的变量可以跨线程共享
  • Using keyword synchronized will “lock” the method execution and force other threads to wait until the execution completes 使用关键字同步将“锁定”方法的执行，并强制其他线程等待，直到执行完成
  • Thread can be in different states. After termination, thread can’t be started again (however, you can create a new thread). 线程终止后不能再次启动，但是可以创建一个新的线程

Exception handling （异常处理）

  • An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program’s instructions
  • Exception handler is a block of code that can handle the exception
  • Java allows to separate exception handling code from the normal code to improve the readability
  • Exceptions are propagated across the call stack until exception handler is found so developer can choose at which level exceptions should be handled
  • Each organisation will have its own house style on how to write and handle exceptions

主要层次结构如下：