java-stream

问题 I'm reviewing some old code, where I'm grouping elements. It looks more or less like this: Map<Long,List<Items>> groupedItems = ... for (long groupid : groups){ for (Item item :items){ if (isGroupAccepting(item.getId(),groupid) || groupid == item.getGroup()) { groupedItems.get(groupid).add(item); } } } I planned to replace it using grouping from stream API, but I'm stuck. It works fine for my second condition, but how to deal with the first one, where item should be added to every group which

问题 I'm reviewing some old code, where I'm grouping elements. It looks more or less like this: Map<Long,List<Items>> groupedItems = ... for (long groupid : groups){ for (Item item :items){ if (isGroupAccepting(item.getId(),groupid) || groupid == item.getGroup()) { groupedItems.get(groupid).add(item); } } } I planned to replace it using grouping from stream API, but I'm stuck. It works fine for my second condition, but how to deal with the first one, where item should be added to every group which

问题 I am using this method: public boolean checkRowsFilterNameBy(String filter){ waitForElmContainsText(searchButton, "Search"); List<AuditRow> listRows = auditTable.getTable(); for(AuditRow row : listRows){ if(!row.nameStr.equals(filter)||!row.nameStr.contains(filter)) return false; } return true; } and I want to be able to change it using Stream , I've tried the following, but I am missing something: listRows.stream().forEach(auditRow -> { if(auditRow.actionStr.equals(filter))return true;} else

问题 I am trying to write a java 8 stream collector which mirrors the functionality of rxjava buffer operator I have a working code for this: // This will gather numbers 1 to 13 and combine them in groups of // three while preserving the order even if its a parallel stream. final List<List<String>> triads = IntStream.range(1, 14) .parallel() .boxed() .map(Object::toString) .collect(ArrayList::new, accumulator, combiner); System.out.println(triads.toString()) The accumulator here is this: final

问题 I am trying to write a java 8 stream collector which mirrors the functionality of rxjava buffer operator I have a working code for this: // This will gather numbers 1 to 13 and combine them in groups of // three while preserving the order even if its a parallel stream. final List<List<String>> triads = IntStream.range(1, 14) .parallel() .boxed() .map(Object::toString) .collect(ArrayList::new, accumulator, combiner); System.out.println(triads.toString()) The accumulator here is this: final

问题 I am trying to write a java 8 stream collector which mirrors the functionality of rxjava buffer operator I have a working code for this: // This will gather numbers 1 to 13 and combine them in groups of // three while preserving the order even if its a parallel stream. final List<List<String>> triads = IntStream.range(1, 14) .parallel() .boxed() .map(Object::toString) .collect(ArrayList::new, accumulator, combiner); System.out.println(triads.toString()) The accumulator here is this: final

问题 The following code works and is readable but it seems to me I have intermediate operations that feel like they shouldn't be necessary. I've written this simplified version as the actual code is part of a much larger process. I've got a Collection of Widget , each with a name and multiple types (indicated by constants of the WidgetType enum). These multiple types are gettable as a Stream<WidgetType> though, if necessary, I could return those as some other type. (For various reasons, it is

问题 The following code works and is readable but it seems to me I have intermediate operations that feel like they shouldn't be necessary. I've written this simplified version as the actual code is part of a much larger process. I've got a Collection of Widget , each with a name and multiple types (indicated by constants of the WidgetType enum). These multiple types are gettable as a Stream<WidgetType> though, if necessary, I could return those as some other type. (For various reasons, it is

问题 The following code works and is readable but it seems to me I have intermediate operations that feel like they shouldn't be necessary. I've written this simplified version as the actual code is part of a much larger process. I've got a Collection of Widget , each with a name and multiple types (indicated by constants of the WidgetType enum). These multiple types are gettable as a Stream<WidgetType> though, if necessary, I could return those as some other type. (For various reasons, it is

问题 I have the Person class: import java.util.*; public class Person { private String name; Map<String,Integer> Skills=new HashMap<>(); // skill name(String) and level(int) public String getName(){ return this.name; } public Map<String,Integer> getSkills(){ return this.Skills; } } And the App class: import java.util.*; import java.util.Map.Entry; import static java.util.stream.Collectors.*; import static java.util.Comparator.*; public class App { private List<Person> people=new ArrayList<>(); //