如何用JAVA在Oracle中编写“如果存在则插入更新”

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

public class InsertOrUpdateExample {
    public static void main(String[] args) {
        String url = "jdbc:oracle:thin:@localhost:1521:xe"; // Oracle数据库连接URL
        String username = "your_username"; // 数据库用户名
        String password = "your_password"; // 数据库密码

        try {
            // 连接到Oracle数据库
            Connection connection = DriverManager.getConnection(url, username, password);

            // 定义SQL语句，使用MERGE语句实现"如果存在则插入更新"操作
            String sql = "MERGE INTO your_table t " +
                    "USING (SELECT ? AS id, ? AS name FROM dual) s " +
                    "ON (t.id = s.id) " +
                    "WHEN MATCHED THEN UPDATE SET t.name = s.name " +
                    "WHEN NOT MATCHED THEN INSERT (id, name) VALUES (s.id, s.name)";

            // 创建PreparedStatement对象，并设置参数
            PreparedStatement statement = connection.prepareStatement(sql);
            statement.setInt(1, 1); // 设置id参数
            statement.setString(2, "John"); // 设置name参数

            // 执行SQL语句
            int rowsAffected = statement.executeUpdate();

            if (rowsAffected > 0) {
                System.out.println("插入或更新成功");
            } else {
                System.out.println("插入或更新失败");
            }

            // 关闭连接和Statement对象
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}