merge

boot-service/src/main/java/com/xwbing/demo/CollectionDemo.java

@@ -118,6 +118,8 @@ public class CollectionDemo {
          * lambda表达式
          */
         list.forEach(o -> System.out.println(o));
+        //删除某元素
+        list.removeIf(integer -> integer == 0);
 
         /**
          * 迭代器

boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java

@@ -1,5 +1,6 @@
 package com.xwbing.demo;
 
+import com.alibaba.fastjson.JSONObject;
 import com.xwbing.domain.entity.sys.SysUser;
 import com.xwbing.domain.entity.sys.SysUserRole;
 import com.xwbing.service.sys.SysUserRoleService;
@@ -38,16 +39,23 @@ public class LambdaDemo {
 //        //遍历
 //        Arrays.stream(arrays).forEach(System.out::println);
         list.forEach(System.out::println);
+        lists.sort((o1, o2) -> o1 - o2);//升序排序，不需要收集
         System.out.println("sort:" + lists.stream().sorted((o1, o2) -> o2 - o1).collect(Collectors.toList()));//排序
         System.out.println("map:" + lists.stream().map(o1 -> o1 * 2).collect(Collectors.toList()));//转换
         System.out.println("distinct:" + lists.stream().distinct().collect(Collectors.toList()));//去重(去重逻辑依赖元素的equals方法)
         System.out.println("limit:" + lists.stream().limit(4).collect(Collectors.toList()));//截取
         System.out.println("skip:" + lists.stream().skip(4).collect(Collectors.toList()));//丢弃
+        //匹配
+        boolean b1 = lists.stream().anyMatch(o -> o == 1);
+        boolean b = lists.stream().allMatch(o -> o == 1);
+        boolean b2 = lists.stream().noneMatch(o -> o == 1);
         //过滤
         System.out.println("filter:" + lists.stream().filter(o1 -> o1 > 3 && o1 < 8).collect(Collectors.toList()));
         Predicate<Integer> gt = integer -> integer > 3;//函数式接口Predicate
         Predicate<Integer> lt = integer -> integer < 8;
         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
         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)
@@ -69,6 +77,8 @@ public class LambdaDemo {
         System.out.println("all:" + lists.stream().filter(Objects::nonNull).distinct().mapToInt(num -> num * 2).skip(2).limit(4).sum());
         //遍历list存入map里
         Map<String, SysUser> userMap = new SysUserService().listAll().stream().collect(Collectors.toMap(SysUser::getId, Function.identity()));
+        Map<String, String> nameMap = new SysUserService().listAll().stream().collect(Collectors.toMap(SysUser::getId, SysUser::getName));
+        Map<String, String> jsonMap = new ArrayList<JSONObject>().stream().collect(Collectors.toMap(o1 -> o1.getString(""), o2 -> o2.getString("")));
         //分组
         Map<String, List<SysUser>> groupMap = new SysUserService().listAll().stream().collect(Collectors.groupingBy(SysUser::getSex));//(分组条件为key，分组成员为value)
         //非空判断

boot-service/src/main/java/com/xwbing/service/DemoService.java

@@ -1,4 +1,20 @@
 package com.xwbing.service;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
 public class DemoService {
+    public static void main(String[] args) {
+        List<Integer> list = new ArrayList<Integer>();// 有序
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(5);
+        list.add(4);
+        list.add(6);
+        System.out.println("filter:" + list.stream().filter(o1 -> o1 > 3 && o1 < 8).collect(Collectors.toList()));
+        list.removeIf(o1 -> o1 > 3 && o1 < 8);
+        System.out.println(list);
+    }
 }