title: Error in connecting oracle 11G in localhost using JDBC
body: <pre class="lang-java prettyprint-override"><code>import java.sql.*;
  
  public class one {
  
      public static void main(String[] args)
  
      {
              Connection conn=null;
          Statement stmt=null;
  
          try
          {
          Class.forName("oracle.jdbc.driver.OracleDriver");
              conn=DriverManager.getConnection("jdbc:oracle:thin:@//localhost:1521/ecom","system","manager");
          stmt=conn.createStatement();
          String str="insert into country values(3,'bangladesh');";
          int k=stmt.executeUpdate(str);
          System.out.println(k);
              }
          catch(Exception e)
          {
              e.printStackTrace();
  
          }
  
      }
      }
  </code></pre>
  
  <p>The only jar file I added to the class path is <code>ojdbc6.jar</code> is there any other jar required for connecting with <code>oracle 11g(11.2.0.1.0)</code> I am using eclipse as IDE</p>
  
  <p>here are the errors</p>
  
  <pre><code>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.&lt;init&gt;(PhysicalConnection.java:531)
      at oracle.jdbc.driver.T4CConnection.&lt;init&gt;(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 one.main(one.java:17)
  Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
      at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:359)
      at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:422)
      at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:672)
      at oracle.net.ns.NSProtocol.connect(NSProtocol.java:237)
      at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
      at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
      ... 7 more
  Caused by: java.net.ConnectException: Connection refused: connect
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocket`Impl.doConnect(Unknown Source)
      at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
      at java.net.PlainSocketImpl.connect(Unknown Source)
      at java.net.SocksSocketImpl.connect(Unknown Source)
      at java.net.Socket.connect(Unknown Source)
      at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:141)
  </code></pre>