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[英]Java - How to switch old way block of code null check to Optional null check?
[英]how can I put null check in conditional block when using optional in java?
這是代碼
Optional<Buyer> buyerOptional = Optional.ofNullable(buyerRepository.findById(buyerId).orElse(null));
Buyer buyer = buyerOptional.get();
if (buyer != null) {
} else if (buyerOptional == null) {
response = utility.createResponse(500, KeyWord.ERROR, "Invalid buyer");
}
我想進入 else if block,如果我能得到任何建議,那就太好了。
首先,您不需要再次創建Optional
,因為findById
已經返回Optional
。 您可以使用isPresent()
來檢查值是否存在。
Optional<Buyer> buyerOptional = buyerRepository.findById(buyerId);
if (buyerOptional.isPresent()) {
Buyer buyer = buyerOptional.get();
... // preparing response
} else {
response = utility.createResponse(500, KeyWord.ERROR, "Invalid buyer");
}
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