Question

任何人都可以帮我转换java流吗？

private List<String> takeAllPages(Long iId, String clientId, List<PageSummaryList> pages) {
    IssueHeader issuetHeader = issueApi.get(iId);
    String issueSub = issueHeader.getSubject();
    Set<String> samplePageNames = new HashSet<>();
    for (PageSummaryList samplePage : pages) {
        String entityId = "issue-" + clientId + "-doc-" + samplePage.getName().replace(" ", "-");
        List<TickType> tickList = tickTypeApi.getTickForEntity(EntityType.DELL_SOP, entityId);
        for (TickType tickType : tickList) {            
            String tickName = tickType.getName();
            if (issueSub.contains(tickName)) {
                samplePageNames.add(samplePage.getName());
            }
        }
    }
    return Lists.newArrayList(samplePageNames);
}

Answer 1

因为你没有提供你的代码使用的每个类我都无法测试它，但这是一个应该工作的实现（或者一些小的修复可以工作）。

private List<String> takeAllPages(Long iId, String clientId, List<PageSummaryList> pages){
        IssueHeader issuetHeader = issueApi.get(iId);
        String issueSub = issueHeader.getSubject();

        return pages.stream()
                .flatMap(sp -> {
                    String entityId = "issue-" + clientId + "-doc-" + sp.getName().replace(" ", "-");
                    return tickTypeApi.getTickForEntity(EntityType.DELL_SOP, entityId).stream();
                 })
                .filter(tickType -> !issueSub.contains(tickType.getName()))
                .collect(Collectors.toList());
    }

编辑在基本代码中有一些概念错误（我没有看到你的要求中的一些细节，对不起）但我已经制作了另一个版本，我将保留第一个实现仅供参考

这是正确的代码我认为xD（测试它，我们会弄清楚）。

private List<String> takeAllPages(Long iId, String clientId, List<PageSummaryList> pages){
    IssueHeader issuetHeader = issueApi.get(iId);
    String issueSub = issueHeader.getSubject();
    // Until here it is the same as the code you provided
    // This code should do the exact same as yours but using Streams API.

    // Using the @stream() method i am converting your @pages list (List<PageSummaryList>) to
    // a Stream<PageSummaryList>, so that i can perform various operations upon every item in that list (@pages).
    return pages.stream()
            // Firstly i am converting every PageSummaryList into a Pair (javafx.util.Pair but if you want you can create your own).
            // This pair contains a PageSummaryList and its corresponding Stream<TickType>, basically your first for loop.
            // After this map operation i will have a Stream<Pair<PageSummaryList, List<TickType>>>.
            .map(sp -> {
                String entityId = "issue-" + clientId + "-doc-" + sp.getName().replace(" ", "-");
                List<TickType> stream =  tickTypeApi.getTickForEntity(EntityType.DELL_SOP, entityId);
                return new Pair<PageSummaryList, List<TickType>>(sp, stream);
             }) 
             // Here i have Stream<Pair<PageSummaryList, List<TickType>>>
             // and i want only to keep those where their List<TickType> contains an element whose name is in @issueSub
            .filter(pair -> {
                return pair.getValue().stream()
                    .filter( tp -> !issueSub.contains(tp.getName())
                    .count() > 0;

            })
            // Now i want only the names (its basically i want the Stream<String> (it is in someway your Set<String>
            .map(pair -> pair.getKey().getName())
            .collect(Collectors.toList()); // this is what you want to return, a List<String> (equal to your return statement.
}

Java Stream，如何使用java流中的代码

1 个答案: