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1. HistoryDoug Cuttingis inspired by the the paper,MapReduce: Simplified Data Processing on Large Clusters by Jeffrey Dean and Sanjay Ghemawat from Go... 阅读全文
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虚拟化和抽象化无所不在，计算机科学里有一句老话：所有问题都可以通过增加一个间接层来解决。操作系统是对硬件的虚拟化；许多现代语言所用的虚拟机又是对操作系统的抽象；对象-关系映射层抽象了数据库；负载均衡和虚拟IP抽象了网络终端；云计算（infrastructure as service）虚拟化了Infr... 阅读全文
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如果我们在使用有一个枚举类型时，每次会用到其一项或多项（也就是enum set）时，会怎么做呢？在Java没有引入EnumSet之前，有一种叫int enum pattern（assigning a different power of 2 to each constant）的做法，例如一个字体的s... 阅读全文
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1. Why Use Nested Classes?There are several compelling reasons for using nested classes, among them:It is a way of logically grouping classes that are... 阅读全文
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By the time you write your first complete use case, you’ll realize you’re going to have more extensions than use cases. Extensions are the primary way... 阅读全文
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经常需要在Java中调用其它的脚本(shell,cmd), 以前都用：Runtime r = Runtime.getSystemRuntime();r.exec("whatever you want to run");但是有时侯其运行结果是不可预期的，带来很多麻烦。从java 5.0以后，引入了Pr... 阅读全文
