英文:
How can I convert a for loop into Stream and break it in the middle?
问题
如何将以下代码片段转换为流格式？尝试了filter、foreach和map，但仍然有些问题。
```java
private Status validate(final Type type, final String id) {
for(Validator validator : validators) {
Status status = validator.validate(type, id);
if (status == Status.INVALID || status == Status.VALID) {
return status;
}
}
return Status.UNKNOWN;
}
英文:
How can I convert the following piece of code into stream format, tried filter, foreach and map but still something is wrong.
private Status validate(final Type type, final String id) {
for(Validator validator : validators) {
Status status = validator.validate(type, id);
if (status == Status.INVALID || status == Status.VALID) {
return status;
}
}
return Status.UNKNOWN;
}
答案1
得分: 3
让我们来分解这个循环。首先，您会遍历所有的验证器并调用 validate 函数 - 这是一个 map 操作。如果 status 是 INVALID 或者 VALID，您会返回它 - 这是一个带有 findFirst 逻辑的 filter 操作。如果您找不到任何一个符合条件的，您会返回 UNKNOWN - 这是一个 orElse 操作。将所有这些放在一起：
private Status validate(final Type type, final String id) {
return validators.stream()
.map(v -> v.validate(type, id))
.filter(s -> s == Status.INVALID || s == Status.VALID)
.findFirst()
.orElse(Status.UNKNOWN);
}
英文:
Let's break this loop down. You first go over all the validators and call validate - that's a map operation. If the status is INVALID or VALID, you return it - that's a filter operation with findFirst logic. And if you can't find one, you return UNKNOWN - that's an orElse operation. Putting it all together:
private Status validate(final Type type, final String id) {
return validators.stream()
.map(v -> v.validate(type, id))
.filter(s -> s == Status.INVALID || s == Status.VALID)
.findFirst()
.orElse(Status.UNKNOWN);
}
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