java中获取实体类列表中的某个字段

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;

 }

}