Oracle JDBC连接BUG如何解决

package com;
import java.sql.Connection;
import java.util.Properties;
import oracle.jdbc.driver.OracleDriver;
/**
 * 数据库连接对象管理类
 * @说明
 * @author cuisuqiang
 * @version 1.0
 * @since
 */
public class ConnectionManager {
	private static final String url = "jdbc:oracle:thin:@192.168.1.155:1521:orcl";
	private static final String username = "scott";
	private static final String userpass = "bi123";
	public static void main(String[] args) throws Exception {
		Connection conn = getConnection("1");
		if (null != conn) {
			System.out.println(conn.toString());
		} else {
			System.out.println("NO LINK");
		}
	}
	public static Connection getConnection(String tar) {
		Connection conn = null;
		try {
			OracleDriver driver = new OracleDriver();
			Properties properties = new Properties();
			properties.put("user", username);
			properties.put("password", userpass);
			conn = driver.connect(url, properties);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return conn;
	}
}