java代码实现mysql数据库同步

可以使用Java中的JDBC（Java Database Connectivity）技术来实现MySQL数据库同步。以下是一个简单的示例代码：

import java.sql.*;

public class MySQLSync {
    public static void main(String[] args) {
        String sourceURL = "jdbc:mysql://localhost:3306/source_db";
        String targetURL = "jdbc:mysql://localhost:3306/target_db";
        String username = "root";
        String password = "password";

        try {
            // 连接源数据库
            Connection sourceConnection = DriverManager.getConnection(sourceURL, username, password);
            Statement sourceStatement = sourceConnection.createStatement();

            // 连接目标数据库
            Connection targetConnection = DriverManager.getConnection(targetURL, username, password);
            Statement targetStatement = targetConnection.createStatement();

            // 查询源数据库表
            ResultSet resultSet = sourceStatement.executeQuery("SELECT * FROM source_table");

            // 遍历查询结果并插入目标数据库表
            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                int age = resultSet.getInt("age");

                String insertQuery = "INSERT INTO target_table (id, name, age) VALUES (" + id + ", '" + name + "', " + age + ")";
                targetStatement.executeUpdate(insertQuery);
            }

            System.out.println("MySQL database sync successful!");

            // 关闭连接
            resultSet.close();
            sourceStatement.close();
            sourceConnection.close();
            targetStatement.close();
            targetConnection.close();
        } catch (SQLException e) {
            System.out.println("MySQL database sync failed! Error message: " + e.getMessage());
        }
    }
}

以上代码仅作为示例，实际应用中需要根据具体需求进行修改。在实际应用中，还需要考虑多线程、增量同步等问题。