JDBC连接oracle RAC数据库配置
配置过程，找到tnsname.ora，查看对应的sid的description，为
(DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = werprac3-vip.ttmtech.com.hk)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = werprac1-vip.ttmtech.com.hk)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = werprac2-vip.ttmtech.com.hk)(PORT = 1521))
     )
    (LOAD_BALANCE = YES)
    (FAILOVER = ON)
    (CONNECT_DATA =
      (SERVICE_NAME = PRD1)
    )
  )

java连接RAC:

public static Connection getConnForOracleLive(String username,String password) throws Exception{
		
		//驱动名
		String driverName = "oracle.jdbc.driver.OracleDriver";
		//连接服务器和数据库名
		String url = "jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=werprac3-vip.ttmtech.com.hk)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=172.30.254.36)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=werprac1-vip.ttmtech.com.hk)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=172.30.254.38)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=werprac2-vip.ttmtech.com.hk)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=172.30.254.37)(PORT=1521)))(LOAD_BALANCE=YES)(FAILOVER=ON)(CONNECT_DATA=(SERVICE_NAME=PRD1)))";

		Connection conn = null;
		//加载驱动
		Class.forName(driverName);
		//获取连接
		conn = DriverManager.getConnection(url, username, password);
		System.out.println("获取oracleLive连接成功！");
		return conn;
	}
}