使用JDBC预编译对象查询数据库并封装为List - Java示例

{"title":"使用jdbc预编译对象操作数据库 account表，. 查询所有记录，将其封装为List","content":"\n下面是使用JDBC预编译对象操作数据库account表并将其封装为List的示例代码：\n\njava\nimport java.sql.*;\nimport java.util.ArrayList;\nimport java.util.List;\n\npublic class Main {\n public static void main(String[] args) {\n List<Account> accounts = getAllAccounts();\n for (Account account : accounts) {\n System.out.println(account);\n }\n }\n\n public static List<Account> getAllAccounts() {\n List<Account> accounts = new ArrayList<>();\n\n try {\n // 1. 加载数据库驱动\n Class.forName("com.mysql.jdbc.Driver");\n\n // 2. 建立数据库连接\n Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "username", "password");\n\n // 3. 创建预编译对象\n String sql = "SELECT * FROM account";\n PreparedStatement statement = connection.prepareStatement(sql);\n\n // 4. 执行查询并获取结果集\n ResultSet resultSet = statement.executeQuery();\n\n // 5. 遍历结果集并封装为Account对象\n while (resultSet.next()) {\n int id = resultSet.getInt("id");\n String name = resultSet.getString("name");\n double balance = resultSet.getDouble("balance");\n Account account = new Account(id, name, balance);\n accounts.add(account);\n }\n\n // 6. 关闭连接\n resultSet.close();\n statement.close();\n connection.close();\n\n } catch (ClassNotFoundException | SQLException e) {\n e.printStackTrace();\n }\n\n return accounts;\n }\n}\n\nclass Account {\n private int id;\n private String name;\n private double balance;\n\n public Account(int id, String name, double balance) {\n this.id = id;\n this.name = name;\n this.balance = balance;\n }\n\n // getter and setter methods\n\n @Override\n public String toString() {\n return "Account{" +\n "id=" + id +\n ", name='" + name + "'" +\n ", balance=" + balance +\n '}';\n }\n}\n\n\n请注意，上述代码中的数据库连接URL、用户名和密码需要根据你的实际情况修改。另外，需要将MySQL JDBC驱动添加到项目的classpath中。"}