关于 classpath 和 java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver 问题求解

Question

JB9在开发时使用自己的Libarary库,和系统的classpath无关.

Answer 1

JDBC的驱动程序是动态加载(Class.forName())，不建议在classpath中使用绝对路径

Answer 2

package plusin;import plusin.PConnection;
import plusin.ConnectionException;
import java.util.Properties;
import plusin.PData;
import java.sql.*;
import javax.swing.JOptionPane;/**
 * <p>Title: Oracle connection</p>
 * <p>Description: Oracle connection</p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: www.sclh.com</p>
 * @author etl.zc
 * @version 1.0
 */public class PlusinConnection implements PConnection
{
  private static final String PROPERTY_USER = "user";
  private static final String PROPERTY_PASSWORD = "password";
  private static final String PROPERTY_URL = "url";
  private static final String PROPERTY_TABLE = "table";  private Properties properties = new Properties();
  private Connection connection = null;  public PlusinConnection()
  {
    properties.setProperty( PROPERTY_URL,"");
    properties.setProperty( PROPERTY_USER,"");
    properties.setProperty( PROPERTY_PASSWORD,"");
    properties.setProperty( PROPERTY_TABLE,"");
  }  public void setProperty(String parm1, String parm2) throws plusin.ConnectionException {
    properties.setProperty(parm1, parm2);
  }  public String getProperty(String parm1) throws plusin.ConnectionException {
    return properties.getProperty( parm1 );
  }
  public Properties getProperties() throws plusin.ConnectionException {
    return properties;
  }  public void open() throws plusin.ConnectionException
  {
    if( connection != null )
      throw new ConnectionException("已经打开了数据库连接");
    try
    {
      Class.forName("oracle.jdbc.driver.OracleDriver");
      connection = DriverManager.getConnection(getProperty(PROPERTY_URL),
                                               getProperty(PROPERTY_USER),
                                               getProperty(PROPERTY_PASSWORD));
    }
    catch( SQLException ex )
    {
      throw new plusin.ConnectionException("open操作出现SQLException异常");
    }
    catch( ClassNotFoundException ex )
    {
      ex.printStackTrace();
      throw new plusin.ConnectionException("open操作出现ClassNotFoundException异常");
    }  }
  public void close() throws plusin.ConnectionException
  {
    if(connection == null)
      throw new plusin.ConnectionException("没有打开数据连接,close操作被忽略!");    try
    {
      connection.close();
      connection = null;
      System.gc();
    }
    catch( SQLException ex )
    {
      throw new plusin.ConnectionException("close操作失败(SQLException)!");
    }
  }  public PData getData() throws plusin.ConnectionException
  {
    if( connection == null )
      throw new plusin.ConnectionException(",没有打开数据库连接, getData操作失败!");    OracleData data  = new OracleData();
    Statement  state = null;
    ResultSet  set   = null;
    StringBuffer sbSql = new StringBuffer(50);    try
    {
      state = connection.createStatement();
      sbSql.append( "select * from ");
      sbSql.append( getProperty(PROPERTY_TABLE) );      set = state.executeQuery(sbSql.toString());      ResultSetMetaData rsmd = set.getMetaData();
      int iColumnCount = rsmd.getColumnCount();
      for( int i = 1; i <= iColumnCount; i++ )
        data.appendLine( rsmd.getColumnName(i) + " -> " + rsmd.getColumnType(i) );      set.close();
      state.close();
    }
    catch( SQLException ex )
    {
      ex.printStackTrace();
      throw new plusin.ConnectionException("getData操作出现SQLException异常");
    }    return data;
  }  public static void main(String[] args) throws Exception
  {
    PlusinConnection oracleConnection1 = new PlusinConnection();
    oracleConnection1.setProperty(PlusinConnection.PROPERTY_URL,"jdbc:oracle:thin:@192.168.0.250:1521:orcl");
    oracleConnection1.setProperty(PlusinConnection.PROPERTY_USER,"lfj");
    oracleConnection1.setProperty(PlusinConnection.PROPERTY_PASSWORD,"lfj");
    oracleConnection1.setProperty(PlusinConnection.PROPERTY_TABLE,"isep.rk_jbxx");    PData data = null;
    oracleConnection1.open();
    data = oracleConnection1.getData();
    System.out.println(data);
    oracleConnection1.close();
  }
}

Answer 3

我的代码就这样的,应为我这个是个插件. 在工程里面没有添加 oracle for jdbc driver. 
我相单独编译出一个jar出来三.