在非静态上下文中组合双谓词

Question

我为所有过滤器定义了接口：

public interface Filter<I, C> extends BiPredicate<I, C> {}

我将所有这些过滤器作为一个列表注入到我的服务类中：

public class SomeClass {
    private List<BiPredicate<Status, Request>> filters;

    public List<Status> getStatus(final Request requestParameter) {
      final List<Status> summaries == this.repo
              .summary(requestParameter)
              .stream()
              .reduce(BiPredicate::and).orElse((x, y) -> true)
              .test();  //arg1=status from stream, arg2=requestParameter
  }
}

我正在努力完成上述操作并应用集合 filters 中的所有过滤器。 如何将status 和requestParameter 传递给test()？我也收到错误non-static method cannot be referenced from static context？

有没有比我尝试的以下更好的方法：

1. 将allFilters 初始化为字段：

   private BiPredicate<Status, Request> allFilters = 
       filters.stream().reduce(BiPredicate::and).orElse((x, y) -> true);
   

2. 然后调用调用：

   this.repo.statusSummary(request)
       .stream()
       .filter(status -> applyFilters(status, request))
       .collect(toList());`
   

applyFilters():

private boolean applyFilters(Status status, Request request) {
    return this.allFilters.test(status, request);
}

Answer 1

你可能想试试allMatch as

final List<Status> summaries ==this.repo
        .summary(requestParameter)
        .stream()
        .filter(r -> filters.stream()
                .allMatch(f -> f.test(s, requestParameter)))
        .collect(Collectors.toList();

Answer 2

基于answer from this post

final List<Status> getStatus = this.repo
                .summary(request)
                .stream()
                .filter(status-> this.filters.stream().reduce(BiPredicate::and).orElse((x, y) -> true).test(status, request))
                .collect(toList());