java数据库数据分批读取的实现示例

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DatabaseUtil {
    public static Connection getConnection() throws SQLException {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String username = "root";
        String password = "password";
        
        return DriverManager.getConnection(url, username, password);
    }
}

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class StudentDAO {
    private static final int BATCH_SIZE = 100; // 每批读取的数据量

    public void processStudents() throws SQLException {
        Connection connection = DatabaseUtil.getConnection();
        PreparedStatement statement = connection.prepareStatement("SELECT * FROM student");
        ResultSet resultSet = statement.executeQuery();

        int count = 0;
        while (resultSet.next()) {
            String studentId = resultSet.getString("student_id");
            String name = resultSet.getString("name");
            int age = resultSet.getInt("age");
            String gender = resultSet.getString("gender");

            // 处理学生信息
            // ...

            count++;
            if (count % BATCH_SIZE == 0) {
                System.out.println("Processed " + count + " students");
            }
        }

        resultSet.close();
        statement.close();
        connection.close();
    }
}