List转字符串

public MainMessageEntity buildInsert(Long userId, Integer tenantId) {
    return MainMessageEntity.builder()
            .messType(messType)
            .messTitle(messTitle)
            .messContent(messContent)
            .publishTime(publishTime)
            .publishUser(publishUser)
            .status(SysMessageStatusEnum.MSG_STATUS_DRAFT)
            .createTime(LocalDateTime.now())
            .lastModifyTime(LocalDateTime.now())
            .createUser(userId)
            .tenantId(tenantId)
            .lastModifyUser(userId)
            .messReceiveRoleId(Joiner.on(",").join(roleIds))
            .messReceiveRoleName(Joiner.on(",").join(roleName))
            .build();
}
通过Joiner.on(",").join(roleIds) 将list<Long> 属性 roleIds 转换成字符串messReceiveRoleId 保存

另外一种方法

public MainMessageEntity buildUpdate(Long userId, Integer tenantId) {
    return MainMessageEntity.builder()
            .id(id)
            .messType(messType)
            .messTitle(messTitle)
            .messContent(messContent)
            .publishTime(publishTime)
            .publishUser(publishUser)
            .lastModifyTime(LocalDateTime.now())
            .lastModifyUser(userId)
            .tenantId(tenantId)
            .messReceiveRoleId(roleIds.stream().map(n->String.valueOf(n)).collect(Collectors.joining(",")))
            .messReceiveRoleName(roleName.stream().map(n->String.valueOf(n)).collect(Collectors.joining(",")))
            .build();
}
通过 roleIds.stream().map(n->String.valueOf(n)).collect(Collectors.joining(",")) 也可以实现转换。