我一直以为使用的sort()方法是sorted(),导致代码出了个很严重的bug),两者的差异,sort()是对集合本身做操作,会改变集合本身的结构(还是原集合,元素顺序(单只做排序元素本身和排序前是一样的,即元素未发生改变))发生改变,而sorted()不一样,如果不做collect(Collectors.toList())是不会改变原集合的结构的,如下...
importjava.util.ArrayList;importjava.util.Comparator;importjava.util.List;publicclassStudent{privateStringname;privateintscore;publicStudent(Stringname,intscore){this.name=name;this.score=score;}publicStringgetName(){returnname;}publicintgetScore(){returnscore;}publicstaticvoidmain(String[]args){List<St...
1. Creating Comparators for Multiple Fields To sort on multiple fields, we must firstcreate simple comparatorsfor each field on which we want to sort the stream items. Then wechain theseComparatorinstancesin the desired order to give GROUP BY effect on complete sorting behavior. Note thatComparator...
List<Integer> userList2 = new ArrayList<>();userList2.addAll(userList);Long startTime1 = System.currentTimeMillis();userList2.stream().sorted(Comparator.comparing(Integer::intValue)).collect(Collectors.toList());System.out.println("stream.sort耗时:"+(System.currentTimeMillis() - startTime1...
[Java] Stream Sort Sream<Employee> emps =...; emps.sorted( Comparator.comparingInt(Employee::getSalary) .reversed() ).limit(10) .map(Employee::getName) .forEachOrdered(System.out::println); ParalleSteam with unordered() to improve efficiency:...
import java.util.stream.Collectors; public class Sort { public static void main(String[] args) { Listlist = Arrays.asList( new Obj("政府", null), new Obj("政府", new BigDecimal("1216.23")), new Obj("商业", new BigDecimal("123.23")), ...
8,redis使用单线程模型,数据顺序提交,redis支持主从模式,mencache只支持一致性hash做分布式;redis支持数据落地,rdb定时快照和aof实时记录操作命令的日志备份,memcache不支持;redis数据类型丰富,有string,hash,set,list, sort set,而memcache只支持简单数据类型;memcache使用cas乐观锁做一致性。
students.sort((o1,o2)-SpareByNameThenAge(o1,o2)); Assertions.assertEquals(students.get(0),newStudent("caocao",21)); } 6、使用stream排序 在流式计算时进行排序 @Test voidtest(){ ListStudentstudents=Lists.newArrayList( newStudent("caocao",21), newStudent("sunquan",20) ListStudentresult=student...
Back to Stream Sort ↑Question We would like to know how to sort by property value. Answer//fromwww.java2s.com import java.util.Arrays; import java.util.List; public class Main{ public static void main(String[] argv){ List<Person> persons = Arrays.asList(new...
import java.util.stream.Collectors; import java.util.List; import java.util.ArrayList; class HelloWorld { public static void main(String[] args) { AgeRange ageRange = new AgeRange(); ageRange.setBegin(1); ageRange.setEnd(18); Person p1 = new Person(); ...