zoukankan      html  css  js  c++  java
  • JDK1.8新特性之Stream类初识

    JDK1.8新特性之Stream类初识

    import java.util.Arrays;
    import java.util.List;
    import java.util.Optional;
    import java.util.stream.Collectors;
    import java.util.stream.Stream;
    
    public class StreamDemo {
    
        public static void main(String[] args) {
    	    Stream<String> stream = Stream.of("good", "good", "study", "day", "day", "up");
    	    // forEach方法
        	    stream.forEach(System.out::println);
    
    	    // filter方法(输出长度大于3的字符串)
    	    stream.filter((s) -> s.length() > 3).forEach(System.out::println);
    
    	    // distinct(去重复)
    	    // stream.distinct().forEach(System.out::println);
    
    	    // map映射操作,将字符串转大写后再输出
    	    stream.map(s -> s.toUpperCase()).forEach(System.out::println);
    
    	    // flatMap
    	    Stream<List<Integer>> ss = Stream.of(Arrays.asList(1, 2, 3), Arrays.asList(5, 6));
    	    ss.flatMap(list -> list.stream()).forEach(System.out::println);
    
    	    // reduce,找出流中长度最大的字符串
    	    Optional<String> opt = stream.reduce((s1, s2) -> s1.length() >= s2.length() ? s1 : s2);
    	    System.out.println(opt.get());
    
    	    // collect
    	    List<String> list = stream.collect(Collectors.toList());
    	    list.forEach(System.out::println);
    
    	    // ::方法引用
    	    // 引用静态方法:Integer.valueOf
    	    // 引用实例方法:list::add
    	    // 引用构造方法:ArrayList::new
    
        }
    }
  • 相关阅读:
    ixgbe dma 控制器
    per cpu
    HDU 4597 Play Game
    HDU 5115 Dire Wolf
    hdu 5900 QSC and Master
    CodeForces933A A Twisty Movement
    CodeForces 245H Queries for Number of Palindromes
    CodeForces596D Wilbur and Trees
    CodeForces509F Progress Monitoring
    CodeForces149D Coloring Brackets
  • 原文地址:https://www.cnblogs.com/zxfei/p/10907452.html
Copyright © 2011-2022 走看看