Blog / 2010 / September / 20

Java can't connect to Oracle Database

September 20, 2010

I had a problem talking to my Oracle database from Java. Python worked fine. SQL*Plus worked fine. telnet to the Oracle port worked fine. Any connections from Java would give an error with the root cause of:

Io exception: The Network Adapter could not establish the connection.

This had me stumped for a while. We tried copying in a co-workers configuration and Oracle driver (ojdbc6.jar) with no benefit, although the newer driver did give a slightly different error:

java.sql.SQLException: The Network Adapter could not establish the connection
  oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)
  oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
  oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
  oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
  oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
  oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:280)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:207)

oracle.net.ns.NetException: The Network Adapter could not establish the connection
  oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:359)
  oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:422)
  oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:672)
  oracle.net.ns.NSProtocol.connect(NSProtocol.java:237)
  oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
  oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
  oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
  oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
  oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
  oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
  oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:280)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:207)
  oracle.jdbc.pool.OracleConnectionPoolDataSource.getPhysicalConnection(OracleConnectionPoolDataSource.java:139)
  oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:88)
  oracle.jdbc.pool.OracleImplicitConnectionCache.makeCacheConnection(OracleImplicitConnectionCache.java:1583)
  oracle.jdbc.pool.OracleImplicitConnectionCache.makeOneConnection(OracleImplicitConnectionCache.java:515)
  oracle.jdbc.pool.OracleImplicitConnectionCache.defaultUserPrePopulateCache(OracleImplicitConnectionCache.java:222)
  oracle.jdbc.pool.OracleImplicitConnectionCache.<init>(OracleImplicitConnectionCache.java:198)
  oracle.jdbc.pool.OracleConnectionCacheManager.createCache(OracleConnectionCacheManager.java:298)
  oracle.jdbc.pool.OracleDataSource.cacheInitialize(OracleDataSource.java:412)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:393)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:179)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:157)

java.net.SocketException: Malformed reply from SOCKS server
  java.net.SocksSocketImpl.readSocksReply(SocksSocketImpl.java:87)
  java.net.SocksSocketImpl.connect(SocksSocketImpl.java:429)
  java.net.Socket.connect(Socket.java:519)
  oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:141)
  oracle.net.nt.ConnOption.connect(ConnOption.java:123)
  oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:337)
  oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:422)
  oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:672)
  oracle.net.ns.NSProtocol.connect(NSProtocol.java:237)
  oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
  oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
  oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
  oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
  oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
  oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
  oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:280)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:207)
  oracle.jdbc.pool.OracleConnectionPoolDataSource.getPhysicalConnection(OracleConnectionPoolDataSource.java:139)
  oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:88)
  oracle.jdbc.pool.OracleImplicitConnectionCache.makeCacheConnection(OracleImplicitConnectionCache.java:1583)
  oracle.jdbc.pool.OracleImplicitConnectionCache.makeOneConnection(OracleImplicitConnectionCache.java:515)
  oracle.jdbc.pool.OracleImplicitConnectionCache.defaultUserPrePopulateCache(OracleImplicitConnectionCache.java:222)
  oracle.jdbc.pool.OracleImplicitConnectionCache.<init>(OracleImplicitConnectionCache.java:198)
  oracle.jdbc.pool.OracleConnectionCacheManager.createCache(OracleConnectionCacheManager.java:298)
  oracle.jdbc.pool.OracleDataSource.cacheInitialize(OracleDataSource.java:412)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:393)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:179)
  oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:157)

The problem? The SOCKS proxy was configured to use our LAN web proxy. I went into Internet Options, turned the proxy off, and everything worked fine.

References

Tags: oracle java socks