java - 谓词过滤器 rxjava2 - 如何传递动态过滤器参数

Question

我用 rxjava2 构建了一些基本过滤器，它按预期工作。我想知道如何将值/参数传递给过滤器 (return td.getTypeId() == **<value>**;) 。另外，如果有人有关于如何使用 rxjava2/过滤器构建(半)动态查询( Object.<field> == <value> )的想法/线索/示例，我们将不胜感激。

Predicate<TradeDetailed> testfilter;

Flowable<List<TradeDetailed>> td = tr.getTradesDetailedFlowable();

testfilter = new Predicate<TradeDetailed>() {
    @Override
    public boolean test(@NonNull TradeDetailed td) throws Exception {
        return td.getTypeId() == 0;
    }
};

Disposable d = td
        .flatMapIterable(e -> e)
        .filter(e-> testfilter.test(e))
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(t -> {
                        System.out.println("filtered "+t.getReference()));

                    },
                    err -> {
                        System.out.println("error");
                    }
        );

Answer 1

您可以为谓词创建一个单独的类:

class YourPredicate implements Predicate<TradeDetailed>(){

    private final int compareAgainst;

    public YourPredicate(int compareAgainst){
        this.compareAgainst = compareAgainst;
    }

    @Override
    public boolean test(@NonNull TradeDetailed td) throws Exception {
        return td.getTypeId() == compareAgainst;
    }

}