java连接oracle11g报错问题

用java程序连接oracle11一直报以下错：

java.sql.SQLException: The Network Adapter could not establish the connection
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at db.DBTest.main(DBTest.java:19)

问题猜测：
1、网络出问题了
2、监听没启动
3、oracle驱动包有问题

连接代码：

<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />      
       <property name="url" value="jdbc:oracle:thin:@localhost:1521:ORCL" /> 

找了好久都没得到好的解决方法，一直以为是oracle驱动架包的问题，换成最新的驱动架包还是出现此问题，最后在网上看到可能是数据库端口未打开引起的

查看数据库服务器端口1521是否打开

在命令提示符中输入命令：netstat -an如果没有tcp:0.0.0.0:1521说明1521端口没打开

查看后果然没有1521端口，最后在listener.ora和tnsnames.ora文件中看到

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1527))
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1527))
    )
  )

LISTENER_ORCL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1527))


ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1527))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

恍然大悟端口怎么是1527，哎  最后把1521改成1527问题解决