1.JVM总结 https://www.nowcoder.com/discuss/562730?source_id=profile_create_nctrack&channel=-1 2.java集合总结 https://www.nowcoder.com/discuss/565073?source_id=profile_create_nctrack&channel=-1 3.数据库MySQL总结 https://www.nowcoder.com/discuss/579647?source_id=profile_create_nctrack&channel=-1 感谢牛客,元旦快乐