From b91c2397eddc09351fec720940bd3886a1b9a147 Mon Sep 17 00:00:00 2001 From: xiangwbs Date: Fri, 16 Mar 2018 16:46:04 +0800 Subject: [PATCH] merge --- boot-service/src/main/java/com/xwbing/demo/Ademo.java | 7 +++++++ boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java | 6 +++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/boot-service/src/main/java/com/xwbing/demo/Ademo.java b/boot-service/src/main/java/com/xwbing/demo/Ademo.java index 2505118..d094d44 100644 --- a/boot-service/src/main/java/com/xwbing/demo/Ademo.java +++ b/boot-service/src/main/java/com/xwbing/demo/Ademo.java @@ -1,5 +1,8 @@ package com.xwbing.demo; +import java.util.ArrayList; +import java.util.List; + /** * 项目名称: boot-module-demo * 创建时间: 2018/1/23 14:45 @@ -16,5 +19,9 @@ public class Ademo { } System.out.println("11"=="11"); System.out.println("11".equalsIgnoreCase(new String("11"))); + List integers = new ArrayList<>(); + Integer integer1 = integers.stream().reduce((integer, integer2) -> integer + integer2).get(); + System.out.println(integer1); + } } diff --git a/boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java b/boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java index 3128d65..f0299b3 100644 --- a/boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java +++ b/boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java @@ -50,11 +50,11 @@ public class LambdaDemo { System.out.println("重用filter:" + lists.stream().filter(gt.and(lt)).collect(Collectors.toList())); //删除 lists.removeIf(item -> item > 3);//根据条件删除,不用收集 - //聚合 + //聚合(最好给默认值,不然如果list为空时,聚合计算时会报错) System.out.println("reduce:" + lists.stream().reduce((o1, o2) -> o1 + o2).get());//聚合 System.out.println("reduce:" + lists.stream().reduce(0, (o1, o2) -> o1 + o2));//聚合(给定默认值) - System.out.println("ids:" + list.stream().reduce((sum, item) -> sum + "," + item).get());//常用//list(a,b,c)-->,a,b,c-->a,b,c - System.out.println("ids:" + list.stream().reduce("", (sum, item) -> sum + "," + item).substring(1)); + System.out.println("ids:" + list.stream().reduce((sum, item) -> sum + "," + item).get());//list(a,b,c)-->,a,b,c + System.out.println("ids:" + list.stream().reduce("", (sum, item) -> sum + "," + item).substring(1));//list(a,b,c)-->,a,b,c-->a,b,c String s = list.stream().reduce("", (sum, item) -> sum + "'" + item + "',");//list(a,b,c)-->'a','b','c',-->'a','b','c' System.out.println("id in:" + s.substring(0, s.lastIndexOf(","))); //join