在Java编程中，连接Oracle数据库是一项基础且重要的任务，使我们能够与Oracle数据库进行交互。以下是简单的Java连接Oracle的测试代码示例。首先，引入Oracle的JDBC驱动：

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

在GetMetaData.java中：

public class GetMetaData {
    public static void main(String[] args) {
        String url = \"jdbc:oracle:thin:@//hostname:port/service_name\";
        String username = \"your_username\";
        String password = \"your_password\";
        try {
            Class.forName(\"oracle.jdbc.driver.OracleDriver\");
            Connection conn = DriverManager.getConnection(url, username, password);
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.getMetaData();
            while (rs.next()) {
                System.out.println(rs.getString(...));
            }
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}