对于Java中null的缺点和如何处理,大家讨论了很多遍,guava给出的解决方法是Optional<T>
public static Optional<String> getYourName () { return Optional.of("malone"); } public static void main (String[] args) { Optional<String> result = getYourName(); if (!result.isPresent()) { throw new RuntimeException("错误的返回结果!"); } System.out.println(result.get()); Optional<String> newResult = result.or(Optional.of("hi")); System.out.println(newResult.get()); }
Optional<T> 基本用法如上,具体的可以参考api,当你的返回返回单个对象时,最好使用Optional<T>,这样的代码更容易让你想起去做非空校验;Optional<T>不会缩减你的代码量,只是当返回值为null的时候,给你提供一个更有意义的null,降低null在系统中引起的bug
这里是一个更高级的用法http://www.blogbus.com/logs/235334714.html,扩展了Option<T>,扩展成了一种Fluent风格的代码,代码量不会减少,而且有可能变多,不过使代码更优雅,不过这种东西和设计模式差不多,可以帮你加深理解Optional和Fluent风格的代码,但实际应用中很少会做这种扩展
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