Java的Lambda表达式应用(持续更新)

1.集合过滤

list.stream().filter(x->条件).collect(Collectors.toList())

示例

List userList= userService.queryAll();
userList = userList.stream().filter(x -> "zhang".equals(x.getUserName())).collect(Collectors.toList());

2.把老集合的字段提取出来重新生成一个新的集合

list.stream().map(条件).collect(Collectors.toList());

示例

List userList= userService.queryAll();
List collect = userList.stream().map(x -> x.getUserName()).collect(Collectors.toList());