Question

我有一个连接到oracle数据库的java代码。它在Windows机器和Mac上运行良好。但是当我尝试从openstack机器运行代码（在centos上运行）时，我收到错误。通过调试，我发现机器甚至没有连接到数据库。

这是代码

public static void main(String[] args){
        System.out.println("Connection requested");
        String selectStatement = "SELECT * FROM TABLE_NAME";
        Connection connection = getConnection("username","password");
        try {
            PreparedStatement preparedStatement = connection.prepareStatement(selectStatement);
            ResultSet result = preparedStatement.executeQuery();
            System.out.println("Connection successful");
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }

    public static Connection getConnection(String username, String password) {
        Connection connection = null;
        try {
            Class.forName("classname");
            connection = DriverManager.getConnection("url",username, password);
        } catch (ClassNotFoundException e) {
            System.out.println("Connection error\n" + e);
        } catch (SQLException e) {
            System.out.println("Connection error\n" + e);
        }
        System.out.println("Connection acquired");

        return connection;
    }


Exception in thread "main" java.lang.NoClassDefFoundError: oracle/net/ns/Message
    at oracle.net.ns.NSProtocol.disconnect(NSProtocol.java:470)
    at oracle.jdbc.driver.T4CConnection.logoff(T4CConnection.java:515)
    at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:595)
    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(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at com.dal.OracleDBConnection.getConnection(OracleDBConnection.java:289)
    at com.data.format.FeedFormatter.getHistory(FeedFormatter.java:167)
    at com.data.FeedGenerator.generateJson(FeedGenerator.java:143)
    at com.data.FeedGenerator.main(FeedGenerator.java:55)
Caused by: java.lang.ClassNotFoundException: oracle.net.ns.Message
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

我已将代码导出为可运行的jar。因此jdbc驱动程序应该可用。我在这里缺少什么？

编辑：正如评论中所建议的那样，我查看了我创建的jar，我可以看到Message.class存在。而这个jar在OSX中运行良好，而在CentOS中根本没有连接。我可以看到Connection Requested，之后几分钟都没有看到。

无法从centos连接到Oracle DB

0 个答案: