java-8

问题 I have this code. private static Map<Long, List<TimePitchValue>> alternativeMethod(AudioFormat audioformat, List<ChunkDTO> listChunkDTO, long index, int sizeChunk) { int numBytesPerSample = audioformat.getSampleSizeInBits() / 8; int quantitySamples = sizeChunk / numBytesPerSample; long baseTime = quantitySamples * index; Map<Long, List<TimePitchValue>> mapListTimePitchValue = new LinkedHashMap<>(); for (int i = 0; i < quantitySamples; i++) { int time = i; List<TimePitchValue>

问题 I have this code. private static Map<Long, List<TimePitchValue>> alternativeMethod(AudioFormat audioformat, List<ChunkDTO> listChunkDTO, long index, int sizeChunk) { int numBytesPerSample = audioformat.getSampleSizeInBits() / 8; int quantitySamples = sizeChunk / numBytesPerSample; long baseTime = quantitySamples * index; Map<Long, List<TimePitchValue>> mapListTimePitchValue = new LinkedHashMap<>(); for (int i = 0; i < quantitySamples; i++) { int time = i; List<TimePitchValue>

问题 This question already has answers here : Better way to generate array of all letters in the alphabet (16 answers) Closed last month . I want create a list with alphabets with each alphabets for 5 times. I tried a code and it worked, public class AlphabetsTest { public static void main(String[] args) { List<Character> alphabetList = new ArrayList<>(); for (int i=0; i<3; i++){ char chr='a'; if (i==1) chr = 'b'; if (i==2) chr = 'c'; for (int j=0; j<5; j++){ alphabetList.add(chr); } } } } But I

问题 For the example in Java 8 POJO objects filter pojo based on common multiple key combination and sum on one field After summing up, I need to create a new object of Sales type, having the totals ( sum result of group by ) Something like below { "month" : "Total", "year": "2000", "state" : "State1", "city" : "City1", "sales" : "15" } So i have created corresponding constructor in Sales and tried list.stream() .collect(groupingBy(Sale::getState, groupingBy(Sale::getCity, summingInt(Sale:

问题 This question already has answers here : Parsing a Date from a String in Java? (2 answers) Convert Human Date (Local Time GMT) to date (2 answers) How to get current moment in ISO 8601 format with date, hour, and minute? (22 answers) Java SimpleDateFormat for time zone with a colon separator? (11 answers) Closed last year . I need to convert some string date to another format string date String current = "Tue Apr 16 10:59:11 EDT 2019"; I want to get result date String in format ISO-8601 in

问题 This question already has answers here : Parsing a Date from a String in Java? (2 answers) Convert Human Date (Local Time GMT) to date (2 answers) How to get current moment in ISO 8601 format with date, hour, and minute? (22 answers) Java SimpleDateFormat for time zone with a colon separator? (11 answers) Closed last year . I need to convert some string date to another format string date String current = "Tue Apr 16 10:59:11 EDT 2019"; I want to get result date String in format ISO-8601 in

问题 When I do anything with a table, it always show the error: Hibernate: select nextval ('hibernate_sequence') 2019-07-20 16:15:44.877 WARN 58376 --- [nio-9000-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 42P01 2019-07-20 16:15:44.877 ERROR 58376 --- [nio-9000-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : ERROR: relation "hibernate_sequence" does not exist I DON'T want to use hibernate_sequence to share id sequence between tables, but want to define id seq for each

问题 This question already has answers here : Counting trailing zeros of numbers resulted from factorial (10 answers) Closed last month . I'm trying to count the number of trailing zero with a factorial. e.g 4! = 24 So you retrieve 0. 9! = 362880 So you retrieve 1. 10! = 9! x 10 = 3628800 So you retrieve 2. 11! = 10! x 11 = 3.99168E7 So you retrieve 2. static double factorial(double n) { double f = 1; for(int i = 1 ; i <= n ; i++) { f *= i; } return f; } static int numberOfZeros(double f) { int

问题 What is the default value of MetaspaceSize for 64-bit servers? I couldn't find it in the official documentation. I'm observing that in a server JVM process, at times, the GC frequency becomes high and keeps growing. If I restart the service a few times, it returns to stable. I think its due to the JRE upgrade. JVM Heap max size is set to be 6GB but when this problem occurs, we see only 3GB heap being used. Metaspace grows by very little and is almost always full. I tried increasing the

问题 What is the default value of MetaspaceSize for 64-bit servers? I couldn't find it in the official documentation. I'm observing that in a server JVM process, at times, the GC frequency becomes high and keeps growing. If I restart the service a few times, it returns to stable. I think its due to the JRE upgrade. JVM Heap max size is set to be 6GB but when this problem occurs, we see only 3GB heap being used. Metaspace grows by very little and is almost always full. I tried increasing the