JDK8简化if-else
简化if-else
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User user = ... if (user != null) { String userName = user.getUserName(); if (userName != null) { return userName.toUpperCase(); } else { return null; } } else { return null; }
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上面的代码可以简化成:
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User user = ... Optional<User> userOpt = Optional.ofNullable(user);
return user.map(User::getUserName) .map(String::toUpperCase) .orElse(null);
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原文地址:https://www.cnblogs.com/qiumingcheng/p/9951767.html