jdbc连接数据库操作

好久没有操作数据库，今天上午连接Oracle的，竟然不知道怎么操作了，还是把代码贴起来吧，以备后用

Class.forName("oracle.jdbc.driver.OracleDriver");
      conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:dbname", "user", "pwd");
//      state = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
//                                   ResultSet.CONCUR_READ_ONLY);
      state = conn.createStatement();
      tag = true;
      String str = "adsfasdfasdf";
      ResultSet rs = null;
//      rs = state.executeQuery(" select count(*) from LIB_URL where URL = 'b'");
      int b = state.executeUpdate("insert into LIB_URL(URL) values('"+str+"')");
      System.out.println(" ===========b : " + b);