[JAVA的写法]之List的stream()操作

List里的遍历
pmDesignFiles = pmDesignFiles.stream().map((m) -> {
m.setLocalPath(“234234”);
return m;
}).collect(Collectors.toList());

List分组
Map<String, List> engMap = proEngList.stream().collect(Collectors.groupingBy(PjDemandBundle :: getEngId));

List里取值某字段的列表
List proList = proEngList.stream().map(p -> p.getProId()).collect(Collectors.toList());

List里取某条件的列表：
List pcList = lstDetail.stream().filter(e -> "1".equals(e.getSource())).collect(Collectors.toList());

List里用逗号拼接某列：
String nodesName = lstData.stream().map(m -> m.getNodeName()).collect(Collectors.joining(","));

import org.apache.commons.lang3.StringUtils
StringUtils.join(list1, ",")

字符串转数组
List lstStatus = Arrays.asList("2,4".split(","));

对象转数组
Arrays.asList(a) 或 new ArrayList<>(a)

import com.google.common.collect.Lists;
Lists.newArrayList("2","4" )