java-8

问题 *To preface, I posted a similar question but this time, the output I want is going to be different. Suppose we have a person named Bob, and he has a list of integers he wrote down: bobList = [10, 25, 30, 50] Say there are 3 other lists of random integers that was generated by a system and put into 1 master list: list1 = [1, 10, 20, 25, 33, 55] list2 = [2, 3, 5, 6, 9, 30] list3 = [25, 30, 50, 100] List<List<Integer>> masterList = new ArrayList<>() masterList.add(list1) masterList.add(list2)

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 I'm searching for an ability to chain Predicates and test them together. Thoughts We have conditions for predicates(or else) : 1. P<T>, P<R>, P<S> 2. P<T>.and(P<T>) => P<T> as result P<T>.test(t1, t2) 3. P<T>.and(P<R>) => P<T,R> as result P<T,R>.test(t,r) 4. P<T>.and(P<R>.or(P<S>)) => P<T,R,S> as result P<T,R,S>.test(t,r,s) I have the models class User { private String name; private boolean isActive; public User(String name, boolean isActive) { this.name = name; this.isActive = isActive; } /

问题 We currently have code compiled in Java 8 but we are running that on Java 11 VM. Now we are trying to move our code to Java 11 compile time as well. Wondering if there are any benefits to compiled code in Java 8 vs Compiled code in Java 11 performance-wise, since both compilers will produce different class files (bytecode)? How does one differ from the other in terms of efficiency? 回答1: javac is not an optimizing compiler, so in general, don't expect it to produce "faster" bytecode from

问题 We currently have code compiled in Java 8 but we are running that on Java 11 VM. Now we are trying to move our code to Java 11 compile time as well. Wondering if there are any benefits to compiled code in Java 8 vs Compiled code in Java 11 performance-wise, since both compilers will produce different class files (bytecode)? How does one differ from the other in terms of efficiency? 回答1: javac is not an optimizing compiler, so in general, don't expect it to produce "faster" bytecode from

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