java 多线程批量修改数据

以下是Java多线程批量修改数据的示例代码：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class BatchUpdateDemo {
    private static final String URL = "jdbc:mysql://localhost:3306/test";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";

    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
            conn.setAutoCommit(false);
            String sql = "update user set age = ? where id = ?";
            pstmt = conn.prepareStatement(sql);

            // 模拟需要修改的数据
            int[] ids = {1, 2, 3, 4, 5};
            int[] ages = {20,21, 22, 23, 24};

            // 创建线程池
            ExecutorService executorService = Executors.newFixedThreadPool(5);

            // 批量修改数据
            for (int i = 0; i < ids.length; i++) {
                int id = ids[i];
                int age = ages[i];
                executorService.execute(() -> {
                    try {
                        pstmt.setInt(1, age);
                        pstmt.setInt(2, id);
                        pstmt.executeUpdate();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                });
            }

            // 关闭线程池
            executorService.shutdown();
            while (!executorService.isTerminated()) {
                Thread.sleep(100);
            }

            // 提交事务
            conn.commit();
        } catch (ClassNotFoundException | SQLException | InterruptedException e) {
            e.printStackTrace();
            try {
                if (conn != null) {
                    conn.rollback();
                }
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        } finally {
            try {
                if (pstmt != null) {
                    pstmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

该示例代码使用了线程池来批量修改数据，通过创建一个固定大小的线程池，将每个修改操作封装成一个任务，交给线程池去执行。这样可以避免频繁地创建和销毁线程，提高了程序的性能。