java连接oracle数据库代码

package com.yang.jdbc;

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

public class DBUtil {
public static String username = "system";
public static String password = "root";
public static String driver = "oracle.jdbc.driver.OracleDriver";
public static String url = "jdbc:oracle:thin:@localhost:1521:orcl";

Connection conn = null;
PreparedStatement pst = null;
ResultSet rs = null;
public ResultSet getConnection(String sql){
try {
Class.forName(driver);
conn = DriverManager.getConnection(url,username,password);
pst = conn.prepareStatement(sql);
rs = pst.executeQuery();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}

public void close(){
try {
this.rs.close();
this.pst.close();
this.conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
String sql = "select * from emp";
DBUtil a = new DBUtil();
ResultSet rs = null;
try {
rs = a.getConnection(sql);
while(rs.next()){
String empno = rs.getString(1);
String ename = rs.getString(2);
System.out.println("工号："+empno+"，姓名："+ename);
}
a.close();
} catch (SQLException e) {
e.printStackTrace();
}

}
}