使用DBC技术，把班级通讯录管理系统的数据保存在数据库中，实现学生通讯信息管理Java代码及其详细信息

DBC（Database Connectivity）通常指数据库连接，用于在Java程序中操作数据库。为了实现班级通讯录管理系统，我们可以使用JDBC（Java Database Connectivity）API来完成数据存储和管理。以下是一个简单的示例，展示了如何创建表、插入数据以及查询学生信息：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

public class StudentManager {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/class_directory";
    private static final String USER = "username";
    private static final String PASS = "password";

    // 连接到数据库
    public static void connectToDB() throws Exception {
        Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
        if (conn != null) {
            System.out.println("Connected to the database");
        } else {
            throw new Exception("Failed to connect to the database");
        }
    }

    // 插入学生信息
    public static void insertStudentInfo(String studentId, String name, String email) {
        String sqlInsert = "INSERT INTO students (id, name, email) VALUES (?, ?, ?)";
        try (Connection conn = connectToDB();
             PreparedStatement pstmt = conn.prepareStatement(sqlInsert)) {

            pstmt.setString(1, studentId);
            pstmt.setString(2, name);
            pstmt.setString(3, email);

            int rowsInserted = pstmt.executeUpdate();
            if (rowsInserted > 0) {
                System.out.printf("Inserted student %s successfully%n", name);
            } else {
                System.err.println("Failed to insert student information");
            }
        } catch (Exception e) {
            System.err.println("Error while inserting data: " + e.getMessage());
        }
    }

    // 查询学生信息
    public static void queryStudentInfo(String id) {
        String sqlSelect = "SELECT * FROM students WHERE id = ?";
        try (Connection conn = connectToDB();
             PreparedStatement pstmt = conn.prepareStatement(sqlSelect)) {

            pstmt.setString(1, id);
            ResultSet rs = pstmt.executeQuery();

            if (rs.next()) {
                String name = rs.getString("name");
                String email = rs.getString("email");
                System.out.println("Found student with ID " + id + ": Name - " + name + ", Email - " + email);
            } else {
                System.out.println("No student found with ID: " + id);
            }
        } catch (Exception e) {
            System.err.println("Error while querying data: " + e.getMessage());
        }
    }

    public static void main(String[] args) {
        // 示例用法
        insertStudentInfo("101", "张三", "zhangsan@example.com");
        queryStudentInfo("101");
    }
}

在这个例子中，我们假设有一个名为`students`的表，包含`id`, `name`, 和 `email`字段。注意，你需要将`DB_URL`, `USER`, 和 `PASS`替换为你实际的数据库连接信息。