听着,代码骑师。我即将传授一些知识,帮助您将 aurora postgresql 游戏从业余游戏转变为大联盟游戏。我们正在谈论 java 模型和数据库访问器,它们会让您的高级开发人员喜极而泣,而您的 dba 会不会给您买啤酒(取决于您的年龄)。
现在,让我们来分解一下:
public class user { private uuid id; private string email; private string hashedpassword; private instant createdat; private instant updatedat; // constructors, getters, and setters omitted for brevity public boolean ispasswordvalid(string password) { // implement password hashing and validation logic } public void updatepassword(string newpassword) { this.hashedpassword = // hash the new password this.updatedat = instant.now(); } // other business logic methods }
为什么有效:
public interface userdao { optional<user> findbyid(uuid id); list<user> findbyemail(string email); void save(user user); void update(user user); void delete(uuid id); list<user> findrecentusers(int limit); }
为什么如此震撼:
public class aurorapostgresuserdao implements userdao { private final datasource datasource; public aurorapostgresuserdao(datasource datasource) { this.datasource = datasource; } @override public optional<user> findbyid(uuid id) { string sql = "select * from users where id = ?"; try (connection conn = datasource.getconnection(); preparedstatement pstmt = conn.preparestatement(sql)) { pstmt.setobject(1, id); try (resultset rs = pstmt.executequery()) { if (rs.next()) { return optional.of(mapresultsettouser(rs)); } } } catch (sqlexception e) { throw new databaseexception("error finding user by id", e); } return optional.empty(); } @override public void save(user user) { string sql = "insert into users (id, email, hashed_password, created_at, updated_at) values (?, ?, ?, ?, ?)"; try (connection conn = datasource.getconnection(); preparedstatement pstmt = conn.preparestatement(sql)) { pstmt.setobject(1, user.getid()); pstmt.setstring(2, user.getemail()); pstmt.setstring(3, user.gethashedpassword()); pstmt.settimestamp(4, timestamp.from(user.getcreatedat())); pstmt.settimestamp(5, timestamp.from(user.getupdatedat())); pstmt.executeupdate(); } catch (sqlexception e) { throw new databaseexception("error saving user", e); } } // other method implementations... private user mapresultsettouser(resultset rs) throws sqlexception { return new user( (uuid) rs.getobject("id"), rs.getstring("email"), rs.getstring("hashed_password"), rs.gettimestamp("created_at").toinstant(), rs.gettimestamp("updated_at").toinstant() ); } }
为什么这是天才:
aurora 可以处理大量连接,但不要浪费。使用 hikaricp 或类似的连接池。
当需要插入或更新多条记录时,请使用批量操作。
public void saveusers(list<user> users) { string sql = "insert into users (id, email, hashed_password, created_at, updated_at) values (?, ?, ?, ?, ?)"; try (connection conn = datasource.getconnection(); preparedstatement pstmt = conn.preparestatement(sql)) { for (user user : users) { pstmt.setobject(1, user.getid()); pstmt.setstring(2, user.getemail()); pstmt.setstring(3, user.gethashedpassword()); pstmt.settimestamp(4, timestamp.from(user.getcreatedat())); pstmt.settimestamp(5, timestamp.from(user.getupdatedat())); pstmt.addbatch(); } pstmt.executebatch(); } catch (sqlexception e) { throw new databaseexception("error batch saving users", e); } }
使用单独的 datasource 进行读取操作以分散负载。
使用事务进行需要原子性的操作。
public void transferMoney(UUID fromId, UUID toId, BigDecimal amount) { String debitSql = "UPDATE accounts SET balance = balance - ? WHERE id = ?"; String creditSql = "UPDATE accounts SET balance = balance + ? WHERE id = ?"; try (Connection conn = dataSource.getConnection()) { conn.setAutoCommit(false); try (PreparedStatement debitStmt = conn.prepareStatement(debitSql); PreparedStatement creditStmt = conn.prepareStatement(creditSql)) { debitStmt.setBigDecimal(1, amount); debitStmt.setObject(2, fromId); debitStmt.executeUpdate(); creditStmt.setBigDecimal(1, amount); creditStmt.setObject(2, toId); creditStmt.executeUpdate(); conn.commit(); } catch (SQLException e) { conn.rollback(); throw new DatabaseException("Error transferring money", e); } finally { conn.setAutoCommit(true); } } catch (SQLException e) { throw new DatabaseException("Error managing transaction", e); } }
利用 aurora 的快速克隆进行测试,及其在连接处理中卓越的故障转移功能。
为 aurora postgresql 创建坚如磐石的 java 模型和 dao 不仅仅是编写有效的代码。它是关于打造一个强大、高效且能够满足您的任何需求的数据层。
请记住,您的模型和 dao 是应用程序的基础。把它们做好,你就为成功做好了准备。如果弄错了,你就会在流沙上建造。
现在停止阅读并开始编码。您的 aurora postgresql 数据库正在等待被驯服。