1.并行Stream和串行Stream
//并行 @Test public void parallelTest(){ List<String> bigLists = new ArrayList<>(); for (int i = 0; i < 10000000; i++) { UUID uuid = UUID.randomUUID(); bigLists.add(uuid.toString()); } long startTime=System.nanoTime(); long count=bigLists.parallelStream().sorted().count(); long endTime=System.nanoTime(); System.out.println(TimeUnit.NANOSECONDS.toMicros(endTime-startTime)); }结果:2124943
//串行 @Test public void parallelTest(){ List<String> bigLists = new ArrayList<>(); for (int i = 0; i < 10000000; i++) { UUID uuid = UUID.randomUUID(); bigLists.add(uuid.toString()); } long startTime=System.nanoTime(); long count=bigLists.stream().sorted().count(); long endTime=System.nanoTime(); System.out.println(TimeUnit.NANOSECONDS.toMicros(endTime-startTime)); }//结果:7690702
并行操作将性能提高了很多,根据实际场景将选择是否使用并行,如果你现在还是单核处理器,而数据量又不算很大的情况下,串行流仍然是这种不错的选择