java中获取实体类列表中的某个字段
List<SysUser> sysUserList
List<String> usernameList = sysUserList.stream().map(SysUser::getUsername).collect(Collectors.toList());
String usernames = StringUtils.join(usernameList.toArray(), ",");
java中在实体类列表中根据id条件筛选
List<SysUser> sysUserList
List<String> idList = Arrays.asList(ids.split(","));
List<SysUser> exportList = sysUserList.stream().filter(item -> idList.contains(getId(item))).collect(Collectors.toList());
private String getId(SysUser item) {
try {
return PropertyUtils.getProperty(item, "id").toString();
} catch (Exception e) {
e.printStackTrace();
return null;
}
}