java连接远程oracle的问题,请帮忙看看什么原因,怎么解决?谢谢!
这是连接远程oracle数据库的代码:
public static Statement conn(String DBServer_IP, String DB_name, String username, String password){// 实现数据库的连接,并返回Statement对象
try {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String url = "jdbc:oracle:thin:@" + DBServer_IP + ":1521:" + DB_name;
Connection conn = DriverManager.getConnection(url, username, password);
Statement stmt = conn.createStatement();
return stmt;
}catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}
下面是在eclipse中运行时显示的错误信息:请帮忙看看是什么原因,怎样解决?
java.sql.SQLException: Io 异常: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=186647552)(ERR=12505)(ERROR_STACK=(ERROR=(CODE=12505)(EMFI=4))))
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:180)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:222)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:335)
at oracle.jdbc.driver.OracleConnection.(OracleConnection.java:361)
at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:442)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:321)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at DB_Oracle.conn(DB_Oracle.java:44)
at DB_Oracle.query(DB_Oracle.java:58)
at DB_Oracle.main(DB_Oracle.java:24)
Exception in thread "main" java.lang.NullPointerException
at DB_Oracle.query(DB_Oracle.java:71)
at DB_Oracle.main(DB_Oracle.java:24)